TreePlantingSolutions_BestPracticesManual

Tree Planting Solutions in Hard Boulevard Surfaces Best Practices Manual Project # A210 65 Date February 8, 2013

Recipient

Submitted by

City of Toronto

DTAH, Lead Consultant ARUP, Eng ine eri ng James Urban, Urban Trees + Soils Urban Forest Innovations, Arborist

| ARUP | James Urban - Urban Trees + Soils Soils | Urban Forest Innovations Inc.

Consultant Team

Ack now le ledgm dgm en ents ts

Hillier,, DTAH Adam Nicklin, G erardo Paez-Alonso, John Hillier Clara Kwon, Michelle Lazar, Donna Bridgeman, Karen Honsinger, Elnaz Sanati, Ayako KItta, Johanna Evers, Jacob Mitchell, Bob Allsopp, René Biberstein

City of Toronto

Parks, Forestry & Recreation Peter Simon, Mark Ventr esc a, Jul Julia ia M urn agh an, Mar k Mulli M ulli ns City Planning Robert Freedman, Jane Welsh, Sheila Boudreau

ARU P Harold Sich, Ken Bontius

Toronto Water Patrick Cheung, Carmelo Pompeo Technical Services Mario Goolsarran, Chris Myers, Nhat-

Urban Trees + Soils James Urban Urban Forestry Innovations Philip van Wassenaer, Alex Satel

Anh Ngu yen, Pete r Pilat P ilateri eri s, Wai Yeung Transportation Services And Services And re Rud Rudnick nick y, Ely ze Park P arker, er, Susan Samuels, Robert Mays Waterfront Secretariat Chris Ronson

Client - City of Toronto

Economic Development & Culture Ant Antone one lla Nic Nicaso aso

Major Capital Infrastructure Coordination Doodnauth Coordination Doodnauth Sharma

Enbridge Gas Rob Milne, Vince Cina Toronto Public Utilities Coordinating Committee

(Cogeco Data Services) Patricia Ritchie DeepRoot Canada Mike James Citygreen Jeremy Bailey ACO Steven Tonaj Gro-bark Earthco Soil Mixtures

II

Tree Planting Solutions for Hard Boulevard Surfaces Best

Practices Manual

Contents Executive Summary

iii

1. Introduction

1

2. General Principles

3

2.1 Principle 1: More Soil Yields Larger, Healthier Trees

4

2.2 Principle 2: Larger Pavement Openings Yield Larger, Healthier Trees 6 2.3 Principle 3: Integrate Utilities into Root Zones, Increase Soil Volume 9

2.4 Principle 4: Strategic Cost-Efficient Design

11

3. Construction Methods & Repair Regimes

13

3.1 Type-1: Pavement Brid ge Syste m

14

3.2 Type-2: Soil Cell System

18

3.3 Type-3: Open Planter System

20

3.4 Hybrid Solutions and Retrofits

21

3.5 Sub-standard Sidewalk Conditions

23

4. Sidewalk Arrangements 4.1 Sidew alk with Growi ng Mediu m Trench (Types -1A, -1B & -2)

26

4.2 Sidewalk with Open Planter and Low Curb (Type-3)

27

4.3 Sidewalk with Open Planter and Raised Seat Wall (Type-3)

28

4.4 Trees and Overhead Wires

29

5. Details

i

25

33

5.1 Tree Opening Surface Options

34

5.2 Tree Protection

36

5.3 Water

38

5.4 Root Zone ID

42


Practices Manual

6. Horticultural Elements

43

6.1 Nursery Stock Quality

44

6.2 Tree Installation

46

6.3 Tree Maintenance

48

6.4 Tree Species Suitabilit y List

50

6.5 Growing Medium

56

6.6 Tree Preservation

63

7. Demonstration Projects

69

7.1 7. 1 Toronto Water Utility Access Exercise

70

7.2 Enbridge Gas Lateral Line and Riser Installation

73

7.3 Bloor Street West at Dovercourt Rd. and

77

Concord Ave. Demonstration Project

Appen dices Appen dix A Construction Drawings Appen dix B Construction Specifications Appen dix C Cost Comparison Appen dix D Nashdene Yard Demonstration Project Appen dix E Bloor-Dovercourt Demonstration Project

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Practices Manual

Executive Summary The City of Toronto has established a goal to increase

SECTION 3 TYPES

both the number and size of its street trees ( Toronto Toronto Street Trees: Guide to Standard Planting Options, Options, April 2010). The City aims to grow large-canopy trees in hard 2010). boulevard surfaces that have a complete 40+ year life span and are 40 cm in diameter at brea st height. This manual examines and provides cost-efficient options to reach this goal. Downtown streetscapes are harsh environments for trees, and many do not sur vive or never grow to a large canopy

S T N E M E G N A R R A Growing 4 Medium N Trench O I T Open C E Planter S with

3.5m min. sidewalk width

5.7m min. sidewalk width

TYPE 1: Pavement Bridge

TYPE 3: Open Planter

1A X

TYPE 2: On-Grade Pavement Over Soil Cells

1B X

X

X

Curb Edge Compatibility between types identified in Section 3 and

size. Large-canopy trees provide enormous climatic, environmental, health, aesthetic and psychological

arrangements identified in Section 4.

benefits. There is room for considerable improvement in the quality of the urban fores t in downtown streetscapes and this report examines how this can be done. Section 1 of this report, the Introduction, defines ‘criteria

for success’ for urban tree planting in Toronto, and sets the tone for the manual and its futur e implementation. Section 2 provides fundamental principles for growing

large trees. At minimum, trees require 20 to 30 m 3 of soil each in order to grow to matur ity. In order to achieve this, integration of soil/root zones with utilities is pro posed to reach the target soil volume under urban sidewalks. Larger openings in the pavement also help to increase longevity. Cost savings are achieved by eliminating

Sidewalk trees on Yorkville Ave.

unnecessary hardware and designing structural concrete to withstand the load of occasional s nowploughs and

Section 6 offers insightful information to ensure that

service vehicles, but not firetrucks.

each planted tree has the best opportunity to thrive. Horticultural topics such as tree preservation, installation

Sections 3 and 4 provide various technical solutions

and maintenance, tree species suitability, nurser y stock quality and soil specific requirements are discussed.

that have been developed as part of this manual. They address both new and retrofit construction and repair techniques to respond to a variety of site-specific requirements such as sidewalk width, public realm condition, and infrastructure arrangement for a range of budgets.

Lastly, Section 7 documents two demonstration projects where the City of Toronto and consultants field-tested a number of the tree planting construction methods. A wa ter mai main n br eak sce nar io was rec rea reated ted and a gas g as lateral and riser were installed throu gh soil cells. In both cases, the soil cells posed no significant hindrance to

Section 5 evaluates essential material components

utility work.

that are required for successful tree growth in an urban streetscape. These are tree opening area materials such as mulch; flexible plastic mesh bark protectors; pas sive

The Ap pe pendi ndi ce ces s include construction drawings, specifications, cost estimates, letters of product

rainwater harvesting and distribution; and root zone ID markers to prevent construction damage.

availability,, responses to Cit y comments and the stre et availability

ii i


tree precedents r eview eview..

Practices Manual

iv


Practices Manual

1. Introduction Purpose

Criteria for Success

The purpose of this report is to outline the best practices

Toronto is a green city with an extensive canopy cover cover..

and technical requirements that are necessary to create healthy growing conditions for trees planted in

Ask anyo ne who has enjo yed the view out of a se con dstorey window in Riverdale, High Park or any one of its

hard boulevard sur faces within the public right-of-way in Toronto. Specifically, Specifically, the document addresses how

established neighbourhoods.

continuous soil trenches can be better implemented

App rox roximat imately ely 10.2 mill million ion tre trees es make up this gre en

in the city to maximize the inherent benefits of tree

cover in Toronto: 6.1 million (60%) on private proper ty

planting projects, while minimizing costs and other encumbrances.

and 4.1 million million (40%) on private propert y. Of the trees on

Background

are crowded out by above- or below-grade u tilities. They struggle to grow and often die and leave a poor

The City of Toronto has made a commitment to planting trees on city streets in order to provide an amenity for

impression on visitors to the city’s core.

pedestrians and beautify the city, as well as to reap the environmental benefits of a healthy urban forest.

In order to meet Toronto’s Toronto’s ambition to grow more and larger urban trees, various departments have come

This commitment is suppor ted by a variety of policy documents, guidelines, bylaws, and planting detail

together to commission this report to evaluate current methods and how they might be improved.

public property, about 600,000 are street trees. These trees often have inadequate soil volume for growth and

standards. In doing so, three overarching directives need to be Continuous soil trenches are part of the City’s Urban

embraced:

Design Streetscape Manual and and have been constructed in the past few year s adjacent to pr ivate development,

Solutions need to support large-sized urban trees.

as well as public road reconstruction projects. Results from these continuous soil tre nch projects indicate that

Solutions must be acceptable to cur rent City of Toronto

the City’s current details add significant costs to road reconstruction budgets and do not provide options for retrofitting areas with existing planting or for projects where only part of the sidewalk is being reconstructed.

standards, and affordable within the current fiscal climate. Solutions must be viable from a utility access and maintenance point of view. They must be designed in a way that it can be realistically maintained. Prior to the report, the team spent time observing and documenting current City of Toronto standards and those of other municipalities and found that Toronto fares well as a progressive centre for urban tree planting. It is hoped that this report can continue the good work, pushing the potential to grow better urban trees, while understanding and respecting the ‘real world’ requirements of utility companies and City departments.

Sidewalk trees on Yorkville Ave.

1

Tree Planting Solutions for Hard Boulevard Surfaces Best Practices Manual / Introduction

The relationship between tree size and soil volume is evident on this section of Bay St., beside City Hall.

2

Tree Planting Solutions for Hard Boulevard Surfaces Best Practices Manual / General Principles

2. General Principles This section provides basic principles for growing large,

The following principles described in this section address

healthy urban street trees in a cost-effective manner.

these needs:

For trees to thrive, they require soil volume, air and water, protection from disturbances and no physical obstacles

2.1 Principle 1: More soil yields larger, healthier trees

to growth. A succe ssful sidewalk requires a safe and durable walking surface that can handle the load of

2.2 Principle 2: Larger pavement openings yield larger, healthier trees

snowploughs and the occasional deliver y vehicle without caving in.

2.3 Principle 3: Integrating utilities into tree root zones increases soil volume

2.4 Principle 4: Strategic, cost-efficient design yields larger, healthier trees

Treed streetscape on St. George St., University of Toronto St. George campus.

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2.1 Principle 1: More Soil Yields Larger, Healthier Trees It is a fact that more lateral s oil volume will yield larger,

Key Recommendations

healthier trees. •

Individually-planted trees each need a minimum of 30m 3 of soil (in contrast to the current City

•

•

•

•

standard of 9m 3 of soil per tree).

Each cubic metre of soil volume will support approximately 2.2m 2 of tree canopy area (canopy area

A g rou pi ping ng of ≥ 2 tr tree ees s i n a soi l b ed nee d a

is defined as the area on the ground directly under the canopy). Accommodations must be made laterally, as

minimum of 20m 3 of soil per tree.

trees roots run laterally rather than vertically down.

Ade qua te soi l d ep epth th is 1m; gr grea eater ter de dept pth h if if

A sing s ingle, le, mat mature ure tre e wi th a cano c anopy py diam d iameter eter of 4 m

available is better; minimum soil depth is the depth of the tree’s root ball

requires 30m 3 of soil volume. Street trees that share soil resources in a continuous trench or planting bed

Where existing soil resources are available, t hey

require 20m 3 of soil volume per tree to achieve a healthy, mature size. In places where especially large, long -lived

should be used.

trees are essential to the streetscape, such as important boulevards and promenades, shared soil volumes of

An ap appr proac oac h t ha hatt pri p rior orit itize ize s tota t ota l t re e c an anopy opy si size ze

40m 3 per tree should be pr ovided, if space and budget allow.

over quantity of trees, should be used. 30-40 m 3 Soil = 66-88 m 2 Canopy

3

9 m Soil = 19.8 m 2 Canopy

Native soil resources may be available in the urban condition. This can off set the volume of new growing medium brought to site to reach the reco mmended soil volume. Urban trees find soil resou rces in many places besides the planting soil provided. These can include

3m

d a r d a n S t i t y 3 C m 9

m 1

3

m 0 - 4 0 3

3m 5.5 m 5.5 m Comparison of the tree height attainabl e from the soil volume of the

Single, large trees have a significant streetscape impact.

current City standard tree detail (covered trench T3-A) to the tree height attainable with recommended target of 30-40 m 3 soil volume.

4


cracks within the pavement and thin spaces under the

sizable canopies, not precise layout, provide streets cape

pavement; soft soils not properly compacted by the contractor; backfills around utility lines; air spaces or

impact.

poorly compacted soil along baseme nt walls and the walls of utility structures. There are also many areas

Tree canopy size is a better measure of impact than the quantity of trees. In order to grow large, healthy trees,

in Toronto where remnant native soils exist under the pavement that are accessible to tree roots. In areas

they must be planted at a distance wide enough to allow each tree the recommended so il volume.

where it can be demonstr ated that the existing soil can contribute to the required soil volume, these existing soil

As an exam ple, con side r an a n inst i nst anc ance e wher w her e a str stretch etch of

resources should be counted in the overall soil volume

sidewalk will support the addition of approximately 80m 3

calculation.

of planting soil. Spacing trees 6m apar t would result in seven trees with just over 11m 3 of soil each and a canopy

Current urban design practices of dense tree spacing do

diameter of 2.8m per tree. On the othe r hand, spacing four trees approximately 10m apar t would achieve a

not allow the recommended minimum of 20 to 40m 3 of soil per tree. Because densely-spaced trees with less soil each have smaller canopies and shor ter lifespans than widely spaced trees, the design details that accompany this report re commend the latter, so that each tree will

shared volume per tree of 20m 3 and a ca nopy diameter of 4.6m per tree. With fewer trees a nd greater soil volume per tree, the difference in tree growth and impact on the streetscape will be significant.

achieve 20 to 40m 3 soil volume. Designers can also adjust the positioning of trees from a perfect grid to irregular spacing in order to avoid growthlimiting conflicts with utilities and street furniture. A s any large, mature stre et tree will immediately illustrate,

6 m spacing

10 m spacing Tighter tree spacing, less soil and smaller canopies on Church St. near its intersection with Yonge St.

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2.2 Principle 2: Larger Pavement Openings Yield Larger, Healthier Trees Key Recommendations •

•

Trees are living organisms that need room to g row. Larger

A 1. 5m x 1. 5m or gr great eat er ope nin g i s ade a dequ quate ate in a

tree openings in the pavement provide room for root flare, trunk growth, ox ygen exchange and rainwater capture

sidewalk condition.

and absorption.

A 1. 2m x 1. 2m ope nin g s hou ld be the ab absol sol ute

An acc accept eptabl able e co mpr mpromi omise se bet wee ween n the t he t ree’s nee ds and the City’s requirements for safe pedestrian areas

minimum size.

is a preferred pavement opening size of 1.5m x 1.5m •

Particular soil-covering materials and practices

or greater and no les s than 1.2m x 1.2m. Where

are preferred for the open area (outlined in Section

pedestrian and City re quirements allow, the tree planting space should be made wider and longer than these

5).

measurements and run par allel to the sidewalk direction. This will significantly increase the health and long evity of the trees. The current City street tree practice provides small root-ball-size openings to minimize trip hazards for pedestrians. Maximizing walking space and allowing pedestrians to walk right up to the tree trunk takes priority over street tree health and longevity. These openings do not allow for trunk growth and provide little opportunity to receive rain water. Trees Trees struggle and die

Inadequate tree opening with priority placed on pedestrian traf fic at

Large tree openings secure more water water,, oxygen and unobstructed

King St. W. and York St.

growing medium for the tree to develop.

6


in these conditions. Next to inadequate soil volume, small pavement openings are the greatest cause of tre e decline or poor growth. The rationale for the 1.5m x 1.5m tree opening recommendation is derived from the following six considerations:

1) Room for root ball and planting: The typical root ball diameter for a 75mm caliper tree is 0.75m. To get this into the ground, an additional 0.3m is needed on each side of it. 2) Room for water infiltration: Trees need regular watering during the first few years after planting. To recover from transplant shock, water is required not just for the root ball soil but also the soil in the rest of the planting space. A small pavement opening makes it very difficult for water to infiltrate the entire planting space. A larger pavement opening for the tree allows water to mor e easily infiltrate the entire soil volume. 3) Room for air exchange: Trees also need soil aeration. The greater the surface area between the air and the soil, the easier it is for air to circulate into the soil. It is critical for newly-planted trees to se nd out roots quickly into the soil to replace lost roots. Many cities have resolved that a 1.2m x 1.2m planting space that provides about 0.25m of space aroun d the tree is sufficient. Outcomes achieved in these tight conditions, compared to larger planting areas, have shown that more space is imperative for rapid establishment. While there is no absolute minimum or even an optimal minimum in the industry, a larger opening is simply bet ter. City safety and maintenance concerns must be bet ter balanced with the needs of trees. 4) Room for root collar development: Some of the first roots that emerge from the root ball develop into the tree’s structural root system. These root s ensure that the tree stands upright and remains firmly in the ground. They run laterally away from the trunk. Ideally, paving would be at least 2m away from the trunk so that these structural roots are firmly established. This would require a large tree opening in the pavement and would cons ume more sidewalk width than is available on most city streets. A compromise would be to r un the planting space

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Tree outgrowing its opening at the corner of Cumberland St. and Bellair St.

Unmanaged precast tree cover on Spadina Ave. now poses a trip hazard.


parallel to the sidewalk alignment. The tree can adapt and develop an asymmetrical structural root collar which, would still be adequate for long-term health and growth. finish ished ed gra de, 5) Room for trunk flare growth: At t he fin the trunk subdivides into a number of structural roots that run perpendicularly away from it. The tree transfers vertical stress loads horizontally outwards and develops large amounts of wood in this area, which causes the trunk flare. This is analogous to a structural engineer adding more steel or reinforcing at a s imilar stress joint in a structure. The trunk flare is typically up to three times the diameter of the trunk, as measured 1 m above the ground. Any obstruction of the developing trunk flare will cause significant problems for the future growth of the tree. Trees growing in 20m 3 (grouped trees) or 30m 3 (individual trees) of soil would be expected to grow to at least a 0.4 to 0.5m trunk diameter diameter,, with a 1.2 to 1.5m diameter trunk flare. This is in addition to any expansion needed for the root collar. To fully accommodate this growth, planting spaces wider than a typical sidewalk would ideally be made available. However, However, because this is unrealistic in an urban set ting, the larger the planting space that can be provided, the better. This dynamic zone requires a surface tr eatment that accommodates the change from soil to wood over a 20- to 30-year period, while not posing a trip hazard. Recommended materials are discussed in Section 5 of this report.

Tree at the corner of Queen St. W. and Northcote Ave. Note the large trunk flare in relation to trunk size.

6) Room for maintenance: When the tree dies, the stump, all the wood in the trunk flare, and much of the wood in the root collar will require rem oval to make room for a new tree. The Cit y of Toronto typically uses a hydro vac to remove the soil. The stump is then cut ou t of the ground. These machines nee d space to operate safely and effectively. The cutting blade can be damaged if it hits the adjacent paving, if it is located too close to the tree. A larger tre e opening makes this work easier.

Trunk flare development is directly linked to the growth of the tree.

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2.3 Principle 3: Integrate Utilities into Root Zones, Increase Soil Volume Key Recommendations •

Utilities should be permitted to run through tree

Current standard practice for utilities and tree placement restricts allowable soil volumes for tree root zones. ‘Horizontal zoning’ of utilities and tree zones is practiced

root and soil zones.

where trees must be horizontally set back away from utilities above and below finished gr ade. Utilities and

•

Existing root ball setbacks should be maintained.

trees are not permitted to to overlap, greatly reducing the area into which tree roots can spread.

•

New standard street tree details are proposed to

•

allow for easy utility maintenance and repair.

In order to attain the soil volumes recommended for

New standard street tree details are proposed to

healthy, mature, long- lived street trees, utilities should healthy, be permitted within tree root zones. Utilities can be

accommodate a range of utility scenarios.

Vertical Zoning

combined with the area of soil volume below the sidewalk. This approach might be referred to as ‘vertical zoning,’ allowing the root zone to be above or even in the same space as the utilities. Current standard setbacks for root balls should largely remain unchanged. The latest Enbridge Gas standards allow for root balls on top of main and lateral gas lines, except within a 2m radius of main and lateral intersections. Integrating utilities within the root zone requires the acceptance and support of utility stakeholders. This new standard asks utility companies to become comfortable in accessing utilities through a ro ot zone, whether the sidewalk is a structural concrete slab or supported by soil cells. L A R E T A L S A G

No root balls

Proposed tree trench can be combined with utilities corridor when

2 m s u d i r a

necessary and where possible have a vertical zoning. GAS MAIN

Root Ball

Root Ball

No root balls

Horizontal Zoning

Root Ball

Latest Enbridge Gas standard: No root ball above intersection of main and lateral gas lines and within 2m of this intersection. Root Existing tree planting standard emphasizes the separation of

ball can be placed above main and lateral lines outside of the 2m

utilities and root zone

radial clearance zone

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The roots of the tre e, including mature ones, taper r apidly

Type 1: Pavement Bridge System

beyond 1 m from the trunk, making cutting through or breaking the roots fairly simple–either in open soil or in soil cells. In fact, most u tility companies are proficient in working close to root zones in the many pre-War single family home neighbourhoods aro und Toronto, where front yard street trees grow to considerable sizes. Section 3 of this report outlines proposed new City standards for urban s treet tree planting in hard boulevard surfaces. Each one has unique implications for access to

Poured in place reinforced concrete paving slab

utilities. They are explained in more detail in that section, along with detailed instructions for utility access and sidewalk repair. All tre e pl ant anting ing sys system tems s prop p ropose ose d in this rep or t are a re designed to allow easy and efficient res toration of the sidewalk to the original state after utility repair below grade. Three types of pavement construction are proposed: Type 1, a ‘pavement bridge system,’ where the

Precast concrete panel under unit paving

pavement spans from one suppor t to another; Type 2, a ‘soil cell system’; and, Type 3, an ‘open planter system.’

Type 2: Soil Cell System

The pavement bridge system requires immediate repair or replacement of the structural bridge to re-establish a safe walking surface. The soil cell system can be repaired with a two-stage process if desired. This is due to the pavement surface itself not being required as str ucture. Pavement could be a slab-on-grade or unit paving over granular base. The

Unit paving over soil cells

rigidity comes from the soil cell system, which would require replacing prior to finishing the sur face repair. The open planter system offers fairly free access to any utilities within the root zone. Some repairs to retaining walls or curbs around the planting zone may be required. All sta nda ndards rds pro pos ed in t his rep repor or t are a re des design igned ed wit with h maintenance access and repair in mind.

Poured in place concrete paving over soil cells Type 3: Open Planter System

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2.4 Principle 4: Strategic Cost-Efficient Design Key Recommendations •

•

•

The challenge to design new City of Toronto street tree

Use the open planter system where space permits.

standards was two-fold: to both improve tree grow th potential and to reduce costs. While the cur rent City of

Use fewer components.

Toronto standards are very progressive for North America in many ways, their s oil volume yield is too low.

Assum As sum e s tr truc uctu tura rall s id idewa ewa lk loa ds for mi d-s ize

To provide the desired 20 to 30m 3 of soil to grow trees to

service vehicles, but not firetrucks.

maturity, the design of hard boulevard surfaces requires a structural suppor t to allow the sidewalk to span over

•

Invest in fewer trees per soil volume to increase the potential for each to reach maturity.

a non-compacted soil zone. The area of structural pavement in the proposed details is almost double that of

Precast tree covers at Spadina Ave. in conflict with trunk flare.

Unmanaged tree guard at Park Rd. and Church St. cutting into tree

Unmanaged tree grate at Queens Quay Blvd. is now a trip hazard.

trunk.

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the current City details, which provide only 10 to 12 12m m 3 of

repair might be necessary, but it seems prudent not to waste

soil per tree.

money in over-designing. To upgrade the sidewalk details to withstand fire truck loading would typically be an upcharge

The majority of the costs of the new details lie in this structural system, running significantly over and above

of 10 to 20% of capital cost–a considerable expense when considered city-wide.

those of a non-stru ctural sidewalk. However, However, in order to provide adequate soil volume for mature tree growth, a

4) Fewer but healthier trees: This report makes a case

structural sidewalk is required. This incre ase in cost is

for quality versus quantity of trees (discussed in section

therefore unavoidable, but can be offset by other savings.

2.1).Following this principle, further savings can be made.

The proposed details provide a rang e of options for a range of budgets and site conditions, while providing the 20 to 30 m 3 of soil required to grow tr ees to maturity. Where possible, reductions in material, components, structural load and trees are recommended as follows:

Although the volume of s oil being made available may be the same, a reduction of the number of trees planted will improve tree health and size, while reducing costs. This is achieved by cutting down on the number of tree openings and by reduced labour associated with planting. Most importantly, growing larger, longer-lasting trees which do not need to be replaced as often cuts down on long-term replacement costs.

1) The open planter system: The open planter system

has the least amount of concrete and requires no structural support system. Where sidewalk widths are great enough, it is the most cost effective approach for planting in urban conditions. Successful installations can be found on Dundas St. E. near Regent Park, as well as by the Market St. condominiums, south of St. Lawrence Market. Planters can be aligned near the curb or at the inside of the sidewalk, by the building frontage. Adequate pedestrian clearways should be provided for both options. If the overall tree planting implementation budget decreases, then the City will have to consider this approach in an growing number of situations. 2) Fewer components: Where there is not adequate

sidewalk width to accommodate the open planter system, the next step is to reduce the number of components required. The priority should always be placed on budgeting for and providing the recommended minimum soil volume. Any extra budget can be spent on openin g interfaces such su ch as tree grates or guards. While guards and grates provide additional pedestrian area and prevent soil compaction, they may also become an encumbrance once the tree starts to take on girth or if it needs replacing. 3) Less Load: Details included in this report are engineered

to support the load of sidewalk ploughs and mid-size service vehicles. Currently, it is the policy of the Toronto Fire Services to not drive on a sidewalk or put down an outrigger unless it is part of a dedicated fire route. In the rare event that the sidewalk load is exceeded due to misuse, some

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3. Construction Methods & Repair Regimes Three different systems for tree planting in sidewalks are laid out in this section. T hey form the basis for the proposed City of Toronto tree planting details that accompany this report in the Appendices. In addition, this section makes recommendations for hybrid solutions and retrofits and dealing with substandard sidewalk conditions. 3.1 Type-1: Pavement bridge system: A structural

pavement surface or subsurface spans between supporting ends over the g rowing medium trench. Reinforced precast and cast-in-place concrete panels provide the ‘bridge’. Refer to the T-1A and T-1B Construction Drawings in Appendix A. 3.1 Type 1: Pavement bridge system

3.2 Type-2: Soil cells system: Modular rigid soil cells

support a pavement system above the growing medium. The pavement surface and base can be built directly on top of the hard deck of the soil cells. Refer to T-2 Construction Drawings in Appendix A. 3.3 Type-3: Open planter system: There is no paving

around the tree base. Where there is space for this system on the sidewalk, it is the most c ost-efficient option available for growing large urban trees. R efer to T-3 Construction Drawings in Appendix A. 3.4 Hybrid solution and retrofits: The street is not

rebuilt wholesale, just one or two trees in a block may be affected.

3.2 Type 2: Soil cells system

3.5 Sub-standard sidewalk conditions: Conditions

where the existing space or utility constraints are such that the standards advocated in this repor t are not achievable.

Note: In the following descriptions for utility compatibility with various construction methods, review is based upon the general feasibility of working with such utilities a nd repairs. Ultimately, individual utility companies and City departments will have to reach an agreement for the access and repair of the various conditions generated, and the responsibility thereof. The recommendations in this report are intended to provide a framework for these policy decisions to be made.

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3.3 Type 3: Open planter system

Tree Planting Solutions for Hard Boulevard Surfaces Best Practices Manual / Construction Methods & Repair Regimes

3.1 Type-1: Pavement Bridge System The ‘bridge’ is the simplest concept of continuous hard

below. The slab can also be core drilled at cor ners

pavement surface over the root zone. Two bridge options have been designed: reinforced cast-in-place concrete

and hooks inser ted to lift it out. To avoid core drilling into internal reinforcing, the reinforcing bars should be

panels ( TypeType-1A) 1A) and prec ast panels (Type(Type-1B) 1B).. So il cells can also be used to support the panels.

located by conventional scanning prior to core drilling. Utility is accessed by excavation of planting soil or granular.

Type-1A: Cast-in-place structural concrete panel ‘bridge’

Repair

Construction

If the concrete slab must be broken ope n to access the

A conc c onc rete sla slab b is cas t in plac e and a nd spa spans ns the roo t and a nd

utility, the slab must be repoured with reinforcing to reinstate it as a walkable surface. In this case, a two-

soil zone and around the tree opening. The concrete

stage repair is not possible.

requires reinforcement. See S-1 Construction Drawing in Appendix A). The structural concrete slab rests on the back saddle of the curb at the roadside an d a grade

If the slab is core drilled and lifted o ut, it could be replaced after utility work, the core drill holes grouted

beam (concrete shoulder) at the back of the sidewalk. Soil is backfilled prior to pouring the structural slab

and the inevitable unevenness between the replaced slab and existing condition feathered smooth with asphalt.

using biodegradable foam board on top of the soil as the concrete form. See T-1A T-1A Construction Drawings in

In this case, a two-stage repair is possible, but not recommended.

App end endix ix A. Recommended compatible utilities Utility access

The slab must be broken open in order to access u tilities

Recommended compatible utilities are those that are generally only accessed in planned repairs, i.e. unlikely

Type 1A 1A -Cast-in-place structural concrete panel ‘bridge’

14


to fail in an emergency situation, except by damage via

Surface finish

other utility works in the area: The concrete surface of the structural slab provides the • New generation storm line (concrete) • New generation sanitary line (concrete)

finished sidewalk surface when poure d in place. This could be used as a base for unit paving. The precast

• Concrete-encased hydro duct, combined data • District energy

option is easier for repair work. See next section on Type-1B.

Not generally recommended:

Pros and Cons

• Pressurized water main • Gas (main or lateral)

The cast-in-place structural concr ete panel ‘bridge’ is

• Bare conduit (street lighting, telephone, etc.)

with unit paving to provide a finished surface. Options for

fairly cost-effective as it does not need to be covered utility access and pavement repair are limited, though.

Utility access, step 1




15


Type-1B: Precast structural concrete panel ‘bridge’

is accessed via excavation of planting soil / granular below.

Construction Repair

A prec p rec ast str uct uctura ura l conc c onc rete pane l fo rms the bas e fo r unit paving. See T-1B T-1B and S -2 Construction D rawings in

After Af ter util ity is back fill ed with gr granu anular lar to u nde nders rside ide of

App end endix ix A. The pan panel el spa spans ns bet wee ween n the t he b ack sad saddle dle

root zone, planting soil is backfilled and pr ecast concrete

of the curb at the roadside, and a grade beam (concrete

slab is laid. Filter fabric is laid back on top of the pr ecast

shoulder) at the back of the sidewalk. So il is backfilled

panels. When a one-stage planned repair is possible, unit

prior to placing the precast structural slab. Once the

pavers should be replaced. When this is not possible,

slab is in place, filter fabric is laid down over the precast panels in order to prevent migration of fines. Setting bed

the finish surface could be replaced with asphalt until permanent repair. This is not recommended un der normal

and unit pavers are installed on top.

circumstances.

Utility access

Recommended utilities compatible with root zone

Unit pavers are removed and set aside. In an emergency

This system is generally compatible with utilities listed

situation where a two-stage repair is absolutely

below since the panels can be lifted out. Procedures

necessary and the crew is not capable of replacing unit

/ agre a gre eme ements nts woul d need n eed to b e nego n ego tiat tiated ed in ord order er to

paving, the unit pavers would be removed from site for future installation. Filter fabric is cut and peeled back,

facilitate the additional scope of the panel removal / replacement:

precast concrete panel is lifted ou t and set aside. Utility

Type 1B 1B - Precast structural concrete panel ‘bridge’

16


• New generation storm line (concrete) • New generation sanitary line (concrete) • Concrete-encased hydro duct, combined data • District energy • Pressurized water main • Gas (main or lateral) • Bare conduit (street lighting, telephone, etc.) Surface finish

Since the precast panels are designed with notches as lifting points, and would not be reliably flus h to each other due to on-site construction tolerances, a surface finish of unit paving is required to be installed on top. Pros / cons

Two pavement systems are re quired: the precast concrete base and unit paving finished sur face. This system is fairly efficient for dismantling and r epairing and revising components. Utility access, step 1


17


3.2 Type-2: Soil Cell System On-grade pavement over soil cells allows for traditional

Construction

pavement on-grade on top of the soil cell a ssembly and has been used in a number of pilot projects in

Space allotted for root zone and foundation are

Toronto and other North American cities. This system requires utility companies and City agencies to become

excavated out, and a compacted gr anular base is excavated installed for the soil cells. Soil cells are installed per

comfortable with the concept of a modular support system, and will require a new protocol to include

manufacturer’s instructions. The pavement system is installed with granular base above the soil cells. T he new

removal and replacement of the soil cells.

paving can be installed in a similar way to any on-gr ade pavement system.

Construction Drawings T-2 in Appendix A provides details on this system.

Utility access

Where there is concrete, the pavement is sawcut. Where there is unit paving, the pavers are removed. Filter fabric is peeled back, and soil cells are removed and set aside. In frozen conditions, the soil cells may be removed forcibly with an excavator, requiring them to be r eplaced with new soil cells prior to repairing surface paving. Once soil cells are removed, the utility is accessed via excavation of planting soil or gr anular below. Repair

Af ter the uti After utilit lity y is i s back b ack fill filled ed wit with h gran g ran ula ularr to the und under ersid side e of the root zone and compacted, soil cells are reinstalled per manufacturer’s instructions. Filter fabric is laid down on top of replaced soil cells, then pavement system is made good either temporarily o r permanently. Recommended utilities compatible with root zone

On-grade pavement over soil c ells is generally compatible with utilities below the root zone, ideally where frequent access is not anticipated. Some shallower utilities may be compatible for placement within root zone / so il cell zone depending on agreement with the u tility company concerned such as gas or hydro laterals. • Utilities below root zones: • New generation storm line (concrete) • New generation sanitary line (concrete) • Concrete-encased hydro duct, combined data • District energy • Pressurized water main • Gas (main or lateral) • Bare conduit (street lighting, telephone, etc.) Type 2: On-grade pavement over soil cells

18


Surface finish

Since the structural support is provided by the soil cells, the pavement system can be any type or finish such as concrete or unit paving over concrete. Pros / cons

If the work crew is comfor table removing and replacing soil cells, the access and repair procedure is similar to current practices. T he pavement system is equivalent to an on-grade construction. It can be repaired as a permanent repair or a temporary two-stage repair. Utility access, step 1

Utility access with pavers, step 1


Utility access with pavers, step 2


19


3.3 Type-3: Open Planter System The open planter is the simplest and most cost efficient

soil is replaced.

way to plant a tree in urban conditions, though it requires the greatest sidewalk space. The planter can be adjacent

Recommended utilities compatible with root zone

to the curb or at the back of the sidewalk adjacent to the building frontage, Currently this system is not a primary

The open planter is gener ally compatible with utilities

approach to sidewalk planting due to spatial concerns; however,, it will inevitably nee d to be a m ore commonly however used standard if overall costs a re to be controlled while delivering better trees. See Construction Drawings T-3 in

below the root zone, since there are no encumbrances. Utility access should be through non-compacted soil. Utilities below root zones:

App end endix ix A fo r deta d etailil d raw rawing ings. s. utiliti liti es tha thatt wo uld be acc access ess ible bel below ow a sof tsc tscape ape • All uti area, can be acces sed through the open planter. Usual

Construction

offsets from tree root ball itself to utility lines should An ope n pl ante r is i s comp c ompose ose d of o f a cur b or o r low l ow s eat wall.

still be respected.

The pavement system is built independently, abutting the open planter. In some instances the edging curb o r low

Surface finish

wall of the open planter may need replacing if the utility straddles them.

The pavement system is independent of the open planter, and can therefore be any surface treatment.

Utility access Pros / cons

An are a of non -c -comp ompacte acte d soil s oil is excav excavated ated to expo e xpo se the utility to be repaired below the root zone. In some

The open planter is the simplest co nstruction and the

instances planting material will require removal.

most cost effective way of delivering a goo d urban tree planting condition. It only suits sidewalks where there is

Repair

sidewalk width for it.

The repaired utility is back filled and compacted; planting

8.00m

Type 3: Open planter system

20


3.4 Hybrid Solutions and Retrofits To implement the pavement bridge or soil cell system, it is assumed that the entire s idewalk is going to be reconstructed for an entire block. An example would be the utility reconstruction of a street revitalization project. In many instances, however however,, funding is made available for minor street alterations, often working in conjunction with a street’s Business Improvement Area (BIA) to make cosmetic improvements to the street. Upgrades can be made to existing tree conditions or to the planting conditions for tree replacements. The following is a guide for minor stre et upgrades to improve growing conditions of street trees: Consider an open planter

The most cost ef fective way to improve growing conditions is to introduce an open planter condition. This may be as simple as enlarging the hole around an existing tree. This can be done on an individual individual tree by tree basis. In a retrof it situation where it is not feasible to greatly improve below ground soil volume, an

Hybrid system: suspended slab on soil cells

enlargement of the planting hole is the be st way to make a tangible improvement. A tree opening of 1.2m 1.2m minimum (1.5m (1 .5m ideal) will make a great impact to a tree’s health. Add soi l c ell s

Combining soil cells to the pavement bridge and open planter systems is another option when existing utilities are in place. As par t of this study, a street retrofit ‘hybrid’ system was designed to improve street tree growing conditions on Bloor Street at Dovercourt Road. In this instance, soil cells were used in conjunction with a precast slab in order to maximize the soil volume in a tight urban street while working around an existing gas main line. Take advantage of existing good soil

Older streets in the cit y that are slated for improvements may have existing soil conditions that are favourable for tree growth. You can often get an indication of this by observing the co ndition of existing street trees nearby. Designers and engineers can also look for for other opportunities to take advantage of nearby soil resources

21

Hybrid system: narrow planter combined with soil cells


in, or even outside of the right of way. way. This might be

Take caution around existing utilities

an area of open garden or parkland, that can be linked to the soil volume around an exiting or pro posed tree

Where pavement is to be removed adjacent to a single,

by installing soil cells or a root path. A root path is a small (150-300 (150-300 mm diameter) sub grade tunnel of non-

existing or proposed tree, a pavement support system such as soil cells or str uctural slab can be installed to

compacted soil that can give a tree roots access to large areas of adjacent soil. They are small enough in size size to

introduce more uncompacted soil volume. It is ge nerally not recommended to install a str uctural slab or soil cell

not affect the stru ctural stability of the pavement system.

system over a legacy utility, such as a clay or brick storm or sewer line. Mos t utilities built from the 1970’s 1970’s onwards are fairly robust and stable.

Possible retrofit for existing trees: install larger open planter whe re conditions are favourable

22


3.5 Sub-standard Sidew Sidewalk alk Conditions Inevitably,, there will be situations where the best Inevitably intentions of this report cannot be met. Tw Two o possible reasons are: Emergency repair of legacy installation

In the instance where an emergency repair is required in the vicinity of a ‘legacy’ or older tree planting installation, it may not always be possible to make improvements without delaying the repair. In this instance, the utility company or City division should notify the Urban Forestry Department that they are dealing with an emergency repair in a legacy tree planting condition. T his gives the Urban Forestry Department an opportunity to inspect the site and make suggestions for modes t improvements, or to confirm proceeding with a repair to match the legacy (existing condition). Other physical constraints

The physical constraints of the surface or below-grade configuration may be such that the s tandards in this report are not achievable. achievable. In a planned repair or street rebuild/improvement, there will be time to consult with the Urban Forestry Department to coordinate an understanding of existing conditions and to agree on an approach that best meets the guidelines given the constraints.

23


Dearborn Parkway, Chicago

24

Tree Planting Solutions for Hard Boulevard Surfaces Best Practices Manual / Sidewalk Arrangements

4. Sidewalk Arrangements Each tree planting system described in Sec tion 3 makes

The three sidewalk arrangements discussed are:

different spatial demands on the streetscape. O ne system will work better than another, depending on the par ticular

4.1 4. 1 Sidewalk with growing medium t rench: A covered

conditions of the streetscape in question.

trench with a series of openings.

The recommendations in this sec tion are intended for use with the most recent City of Toronto Urban Design

4.2. Sidewalk with open planter and low curb : A

14-m-long open trench framed by a sidewalk.

Streetscape Streetscap e Manual and and to be compatible with the selected surface treatment for individual projects as

4.3 Open planter with raised seat wall : A similarly long

desired by the City.

trench framed by a low wall instead of a curb, allowing it to be nar rower.

The only recommended alteration to surface detailing is where it may have an effect on soil volume in narrow sidewalks. Widths are calculated using the recommended

Addi tio tional nally, ly, grou g rou ndnd-leve levell arr a rrang angeme eme nt sol soluti utions ons are discussed with regards to:

minimum pedestrian clear way of 2.1m 2.1m from the City of Toronto’s Vibrant Streets Guidelines. Guidelines . In retrofit or

4.4 Trees and overhead wires: Certain types of wires

substandard sidewalk conditions, this can be re duced to 1.7m clear, as per City guidelines.

can share space with tree foliage, while other s must be avoided for safety reasons. To prevent damage to trees

Tree planting on one side of the street: No

by excessive pruning, care should be taken in where trees are planted relative to overhead wires.

overhead wires or other major underground

No tree planting or small tree planting

restriction.

recommended on any sidewalk where major overhead-wire installation is aligned with the tree planting zone

25


4.1 Sidewalk 4.1 Si dewalk with Growing Medium Med ium Trench Trench (Types -1A, -1B & -2) This is the most spatially efficient arrangement, requiring as little as 3.5 m of sidewalk width. It is also expensive, whether using reinforced concrete or soil cells.

Examples of streets with minimum sidewalk width suitable for gro win g me diu m tr enc hes

In its tightest configuration, the tree opening is restricted to 1.2m wide and directly abuts the curb. In wider sidewalks of 4.4m and up, a deco rative paving band can be used and the optimum tree opening dimension of 1.5m x 1.5m 1.5m can be achieved. Tree spacing should be a minimum of 10m on centre along the curb line. Where underground utilities require at ypical arrangements, soil cells can be added to maximize growing conditions and soil volume.

Bloor St. W. W. west of Ossin gton Ave.

D u n d a s S t. W., we s t o f Hi g h Pa r k Ave .

Ba y S t ., n o r th o f Yo r k v i l l e Ave .

, m 5 . 1 d e d n e m m o c e r m g 2 . n i 1 n e m p u o m e i n e r i T m

d n a B g n i v a P e v i t a r o c e D

Tree spacing recommended 10.0m

y a w r d a e e d m l c n 1 e . n 2 m a i r m m t s o u m e c i d e i n R e P - m

26


d m n u a m B i n n o g i i n m s i v n n a i e P d i m e e d d v i u k t l l a r c a n w o i c t e e o d i D n s e e r t o t d m e 5 . k l s 3 a o : w p l s e o r i a d i p t S t e n d m e g u m n t e i m l i n n i p l a m M i p

4.2 Sidewalk with Open Planter and Low Curb (Type-3) This configuration requires more room on the sidewalk than the growing medium trench systems, with more of the sidewalk must be made available for open soil

Examples of streets with optimum sidewalk width for open planters adj ace nt to cur bs

volume. It is the most cost-ef fective option and due to the large volumes of soil with full exposure to air, it will likely yield the best results. This planting strategy has been used to good effect on Jarvis St. adjacent to the Market condominiums, which is presently showing good indications of tree establishment. The sidewalk requirement is 5.7 5.7m m in width. For this reason, this conf iguration’s use is probably limited to major avenues and new developments. Designers might also consider accommodating the planter s on one side of the street with no tre es on the other (and a tighter, functional sidewalk). This way, the City benefits from one

Bay St., south of Lakeshore Blvd.

row of outstanding trees and canopy, rather than two rows of substandard trees. Planters should be 14m long, plus the width of the surrounding curb. Each planter accommodates two trees, allowing the benefits of shared soil volume. Between planters is a 6m space either for pedestrian circulation or bike parking. Tree planting is still a minimum 10m on centre, both within the planters and from one to the next.

. s b r u c e d i w m 2 . 0 h t i w e d i w m 4 . m 2 8 . r 2 e t n h t a d l i p w n l a e t p o O T

Manitoba St., east of Grand Ave. Ave.,, Etobicoke.

d n a B g n i v a m P 8 . e 0 v i t m a r u m o i c n e i D m

Tree spacing recommended 10.0m Open planter 14m wide with 0.2 wide curbs. Total width 14.8m Tree spacing recommended 10.0m

6.0m

d e m d 1 . n 2 n e a i r y a m m t s w m u m e r o i c n d a i e e e l P c R m

27


m 7 . 5 t n : s e l i m a e t l e p d m i g n o i t t n k a l l a p w e e e d r i t S d m e u s m o i p n o i r M p

4.3 Sidewalk with Open Planter and Raised Seat Wall (Type-3) In this system, the open planter is frame d by a seat wall rather than a curb, allowing it to be narrower, while supporting the same volume of soil. It could be placed

Examples of streets with optimum sidewalk width for open planters adj ace nt to bui ldi ngs

at the back of the sidewalk or adjacent to the curb. T he required minimum width of sidewalk is 6.6m. Where the circulation space is adjacent to the roadway, the City should consider reducing the clear way dimension to 1.7m, which would decreas e the overall sidewalk width 1.7m, requirement to 5.2m. This kind of planter can be se en adjacent to the Regent Park Redevelopment along Dundas St. E. near Parliament St. These planters are cost effective, support great trees, and provide shaded street seating. Bay St., north of Dundas St. W.

Pa r l i a m e n t St ., n o r th of D u n d a s S t . E .

Ba y S t ., n o r th o f Fr o n t St . W.

Tree spacing recommended 10.0 m d e n v a i t B a r g n o i c v e a D P d m e 1 d . n , n 2 a y e i r a m m t u s w m m e r o i d a c i n e e l e m P c r

e h m d t 0 . i d i 2 w r 2 w . l e t 0 a n h t a t o l i T p w . n e s m e d b p i r u 4 . O w c 2

28

Open planter 14.0 m wide with 0.2 m wide curbs. Total width 14.8 m Tree spacing recommended 10.0 m

6.0 m

m m 0 . 5 . 1 2 . . n i n i m m


t n e m 6 m . e 6 l p : s l m i i a o t t e d h t g d i i n t w n k a l l a p w e e e d r i t S d m e u s m o i p n o i r M p

4.4 Trees Trees and Overhead Wires Tree canopies and overhead utility wires often conflict.

High-placed wires are primary distribution and

It is important, however however,, to balance both utility and tre e requirements. A city that resolves all conflicts in favour

transmission power lines, which carry high voltage power and are typically non-insulated bare conductors.

of utility lines is a city that will have a greatly reduced tree canopy. Cities can strike a balance between utility

There is also a t ype of super insulated electric wire that is occasionally used in the Toronto area that can come

needs, reliability of service, and the frequency and type of tree and branch management. Type of tree and the tree

much closer to tree limbs. Lower voltage distr ibution wires and individual building connections require less

location relative to the line alignment and pole height also play a role in this conflict resolution.

stand off distances and are typically lower to the ground. Telephone and other communications

Just as not all trees are the same, not all utility wire s are the same. Each type and class of utility has different needs and function in close pr oximity to trees. It is important that these differences be factored into each decision on how close trees and wires can be placed together.

Communication wires require less sta ndoff, due to the relatively low voltage of wire in these lines. Communication wires are typically the lowest s et of wires on the utility pole. They are often seen running through existing tree canopy rather than having the canopy pruned around these wires.

Hydro Tree height, overhead wires and streetscape quality

Hydro distribution lines have specific requirements for standoff distances to tre e branches. The Cit y of Toronto defers to the guidelines published by Ontario’s Electrical

The ESA guidelines for tree planting nea r hydro power

Safety Authority (ESA) in the document titled Planting

only small trees less than 4.5 m height at maturity. Urban

Under or Around Powerlines & Electrical Equipment . To

streetscapes often have sidewalk widths of 4.5 m o r less and would thus be limited to small trees. This is not in line

avoid tree contact with overhead wires, the guidelines designate Low, Medium and Tall Zones. The Low Zone is the area under the power lines and within 4.5 m of the line where trees or shr ubs should have a maximum 4.5 m height. In the Medium Zone, between the Low Zone and 7.6 m from the power line, maximum mature height of trees should be 7.6 m. Beyond this zone is the Tall Zone, greater than 7.6 m away from the power line, where tree height is not a concern. There is also a Base Zone that is defined around hydro poles where trees /shrubs should

lines permit trees to be planted under hydro lines but

with the goal of this study for large, mature street trees. The City and the ESA should revisit how large street trees can be grown safely around hydro infrastructure. Small trees not only fail to co ntribute significantly to the benefits of the urban tree c anopy anopy,, but the lower height of the branches and canopy cause their own conflicts with other parts of a functioning urban streetscape. Small trees provide few of the benefits desired in an

not be planted within 3.0 m of a pole. The problem with the ESA is that the Low Zone would apply to many str eet

urban streetscape. They do not cool the urban heat

tree locations. In order to create a strong urban ca nopy nopy,,

treat rain water, and do not create a sense of place. The

some modification to this zone is needed.

USDA Forest Service reports that large stature trees provide over four times the net community be nefits of

It is important that high voltage electric lines not come in

small stature trees (benefits minus cost). It is very difficult to prune a small tree and maintain a pleasing shape

contact with tree branches and that tree branches not be in position where a branch loss during a storm may fall on a wire. The higher the load in the line the greater the

island nearly as well as large tr ees, do not capture or

while reducing branch conflicts with re quired pedestrian and vehicular clearances. Low canopies s ignificantly

typical that the higher the lo ad in the wire, the higher the

reduce sight distances of sho p signs. They are never able to reach over the street to shade roadway paving. In

wire is placed on the pole.

addition to the obvious coo ling and rainwater catchment

standoff between the wire and tree limbs. Fortunately it is

benefits, trees shading the roadway sur face have been

29


shown to cause significant increase in the life expectancy

shape of the canopy, the tree can still grow an impressive

of the pavement.

canopy on either side that provides significant be nefits. Structural branch management requires less frequent

Except for with very high wires, there are few trees that are actually small enough to stay below hydro lines

pruning cycles than top shearing.

without some pruning management. Small trees that do eventually grow to the wire level are typically sheared to

The alternative would be to plant trees only whe re there are no overhead wires. Investment should be made in

the required wire standoff. Shearing causes a vigorous

creating large, mature tree canopies w here there are

flush of new branches the following year that grow faster

no obstructions. In an urban streetscape, there may

than the original tree’s growth rate. This then requires even more pruning. Large trees can be structurally

only be hydro poles on one side of the street. The side without hydro poles would be planted with large trees

pruned to grow beside the wires. While this does alter the

that could grow to maturity, provide shade over the

Lakeshore Blvd., east of Islington Ave.: Tree growth compromised by significa nt overhead wiring.

30


sidewalk and street and make a strong visual impact on the streetscape. The City or community must decide if it is worth investing in continuous tree planting on both sides of the street, even if it means small trees under hydro lines or if it is wor th investing in tree planting only where there are no hydro lines, s o that mature canopies are achieved. Species selection

Large trees that have broad and open branching structures such as plane, oak and locust are easier to manage around utility wires tha n more finely branched trees with ascending branch structures, such as maple, linden and pear. Trees such as maple that are prone to develop co-dominant leader s should be avoided. Different trees are k nown to heal from pruning more easily than others through a process of compartmentalization of the wood cell s tructure. Trees known for good compartmentalization should be selected for use under overhead wires. The ESA document Planting Under or Around Powerlines & Electrical Equipment also also provides a species list based on height for planting within var ying proximities to overhead power lines. See Section 6 of this report for an annotated list of appropriate tree species. Tree/wire location

In most street tree applications, particularly with narrow sidewalks, the overhead wires and the tree alignment are often in the same location. Where possible, consider placing some of the trees out into the parking lane to provide some amount of offset in alignment. Large stature trees can be placed in these locations, while smaller to medium stature trees might be placed under the wires. Often, the higher voltage hydro distribution lines are only on one side of the street while the other side may only be local distribution, street-light or building connections. These secondary lines are more compatible with larger stature trees. In these cases, the tendency to plant the same species on both sides of the street should be avoided. Trees, hydro wires and hydro pole on Queen St. W.

31


Street tree planting with low barriers in Columbus, Ohio.

32

Tree Planting Solutions for Hard Boulevard Surfaces Best Practices Manual / Details

5. Details In addition to providing adequate soil volume and complementary paving systems, a few more components are needed to ensure successful establishment of newlyplanted trees and their longterm health. With budget in mind, only the essential components that protect the tree and provide water are evaluated in this section. Design details are also provided in the Appendices. These components should not hinder the growth of the tree. Tree guards, for example, cause more damage than good as, aside from being expensive, they can get engulfed into a growing tree trunk. This section discusses detailing related to the following issues: 5.1 Tree opening surface options : The materials used

to cover the surface exposed by the wider tree openings proposed in this study, as well as fencing options to surround the openings. 5.2 Tree protection: Methods to guard trees from the

damage caused by pedestrians, cyclists, dogs and other hazards.

Minimal design around trees at Bloo r St. W., east of St. George St.

5.3 Water: Systems for collecting rainwater runoff and

directing it to street trees to ensure adequate irrigation. 5.4 Root zone ‘ID’: A proposed system for identifying

individual trees and their root systems to co ntractors and designers.

Tree covers that are now trip hazards and impeding trunk grow th.

33


5.1 5. 1 Tree Tree Opening Openi ng Surface Sur face Options The tree planting opening should be as large as possible. It must also lie outside the r ealm of the pedestrian clearway. The tree will continually increase its volume and shape in the opening and any fixed object in this space will impede its growth. That leaves a fairly large area of open soil in the sidewalk that is gradually changing fr om soil to the wood of the trunk flare and structural root collar. This soil needs to be covered and made more attractive. Of all the material options for tree openings, bark mulch does the greatest good for the tree. The oft-used tree grate is the worst option for tree health and longevity. Other options available for tree opening surfaces are g round covers, gravel mulches, stabilized aggregate and loose set pavers. These will be discussed in order of their impacts on the tree. Bark mulch

Bark mulches are simple, cheap, and ver y effective. Mulches should be shredded hardwood bark placed between 25 and 50mm thick. Filter fabric is not needed below the mulch. The shredded fibres interlo ck and stay in place much better than other types of mulch. Bark

Bark mulch at tree opening

mulch retains water, absorbs salts and chemicals, buffer s temperature and moisture fluctuations and decomposes,

have a positive impact on the tree. Groundcovers should

contributing small amounts of carbo n to the soil. It needs to be replaced periodically once every year until the tree establishes sufficient roots and trunk flare in the space, so that the mulch is no long er needed. The old mulch should be removed prior to adding new mulch so that any contamination can also be removed. This is best done

not be installed within the root ball area of the tree. In tree spaces 1.5m or smaller, there is not enough room for additional planting. Groundcovers are mos t effective in open planter situations with larger and longer tree spaces. To reduce the incidence of damage to these low growing plants, a low barrier or fence can be installed

in the early spring, so that trapped winter salts can be

around the tree space. Gr adually the tree will begin to out-compete the plantings, and they will decline. Trunk

removed before percolating down into the soil below.

flare and roots will fill the tree opening as the tree grows.

While this is the ideal surface option for the tree, it does not have the ‘clean’ image that is often desired for in

Hardy shrubs, perennials and grasses are likely to be the most successful in planter beds, but the list of

many commercial projects. Many designers prefer a machined, modern aesthetic for the ur ban public realm.

permanent plantings suit able for Toronto is limited and the seasonal interest is not n early as exciting as annual

However,, looking at the big picture, a streetscape with However

plantings. Annuals must be r eplaced each year as they

large, mature trees with mulch at their base would receive

will not survive the winter, though they offer a brig hter

greater appreciation than small trees in gravel mulch.

and wider range of colour and excitement in the summer. Ann ual uals s also a lso req requir uire e mo re wate water, r, weedi we eding, ng, rep replac laceme ement nt

Groundcover plantings

and maintenance, all of which is dependent on co ntinued funding. The continuous replanting of annuals does some

pleasing sight. The maintenance of these plantings —

damage to developing tree roots. If the planting is st arted at the time the tr ee is planted, however, the annuals will

watering, fertilizer, mulching and weeding — g enerally

cause the surface ro oting tendency of the tree to develop

A plan p lanting ting bed wit with h grou g rou ndc ndcover over s and a nd tre e is a ve ry

34


at a lower level which may have long-term benefits for

tree may already have occupied sufficient space by that

tree and paving management.

time with roots and the trunk flare that replacement is not needed.

Gravel mulch Perimeter fencing or barriers

Gravel mulch is more permanent than bark mulch. Many designers and developers prefer to use this material

Low fencing could be installed around the tre e opening

in commercial projects. The gravel should be 19 mm

and is useful especially where gro und covers will be

crushed granite, placed 50 mm thick. Filter fabric is not

planted. These low fences are a great opportunity for BIA

needed under the gravel. Gravel does not break down

groups and other street-design stakeholders to create a

and it helps retain water in the soil. Weeds will grow in the gravel as silt and organic material set tles into the gravel,

signature design element for their co mmunity.

so weeding is required. It needs periodic replacement, possibly every 10 years, to keep it fresh. Additionally,

This design element has bee n already considered by the

some maintenance may be required to sweep displaced gravel back into place. In a 1.5m tree opening space, the

2010, pg. 13) and is called “optional decorative protective 2010, railing.”

City of Toronto’s Urban Design Streetscape Manual (April (April

Groundcover planting at tree opening

Granite gravel mulch at E ast Bayfront, Toronto

Low barrier and groundcover at tree ope nings, Main St., Columbus, Ohio

35


5.2 Tree Protection To protect young trees from damage in an urban s etting,

The most common c ause of trunk damage is cyclists

tree protection is required. Protection str ategies, however,, should be cost ef ficient and not cut into the however

locking their bicycles to a tree when ther e are no rings available. The City should provide enough bicycle rings to

budget for the basic necessities for tree growth such as soil volume.

decrease the incidence of this kind of tre e damage. When placed on either side of the tree, bicycle rings also act as barriers to protect trees from pedestrian traffic.

Why a guard in the first place? Options

Newly planted trees have thin bark and are vulnerable to damage from snow plows, bicycles, dogs and other

In high-density and high-traffic sidewalks where tree

threats. As the tree grows thicker bark and a larger trunk, the tree can withstand greater abuse and the need for

protection is a necessity for tree survival, several options are available to protect the trunk during the establishment

trunk protection is reduced. Post-planting, some type of trunk protection can reduce the extent and likelihood of

period. These are low fences or barriers, plastic mesh and metal tree guards.

damage. This protection material must be able to expand with the tree’s growth. T he trunk will g row quickly, adding

Low fences or barriers

up to 12-15 mm to the trunk diameter each year after the tree is established. The tr unk of a newly planted tree

These barriers along the perimeter of the tree opening

also sways in the wind and could be damaged if closely

are very effective as they protect the trunk and ground

surrounded by a hard grate. The ideal trunk protector allows for growth and movement and would thus be

covers. They do not need to be removed and have a long service life. They are likely the most expensive option

flexible or at a sufficient distance to not cause damage.

depending on the design and materials.

Bi cy cyc l e s l o c ke d to to tr tr e e s at at Ja Ja r vi vi s St St. an an d Qu Qu e en en St St. E. E.

L ow fe fe n c e at op op en en i n g ke ke e p s p eo eo p le le aw away fr fr o m th th e tr tr e e an an d prevents damage.

36


Plastic mesh

A mold m olded ed pla plasti stic c me sh tre e tr unk pro tec tectio tion n is a simpl s impl e way to protect the bark. It is currently used on Bloor Street West with great success. It is cheap, reusable, effective, and easy to remove when no longer needed. They are highly recommended. Plastic mes h is cost effective and allows the budget to be directed towards soil volume which is fundamental to the grow th of large, healthy,, mature stre et trees. healthy Metal tree guards

Many different types of metal tree guards are available off-the-shelf. Often these ar e expensive and must be removed as the tree grows. Metal tr ee guards are usually supported by a tree grate or other solid structure. These structures, however, can damage the base of the tree. The tree guard itself mus t be quite large, a minimum of 500 mm in diameter to avoid damaging the tree. Depending on the design, the space bet ween the trunk and the guard can collect tr ash that is then difficult to remove. Tree guards are expensive when compared to

Effective tree bark protector protector (plastic mesh) and sign installed at

the plastic mesh and may be only slightly les s expensive

Bloor St. W. revitalization project.

than tree space barriers. Alt hou hough gh prev iou sly avail able mod models els have bee n inadequate in size to allow for the tree’s early growth, there are now better options available that give sufficient room for a young tree to grow. The minimum recommended clear diameter is 600 mm. Metal tree guards are not recommended for growing healthy,, mature street trees in u rban environments. Where healthy sidewalk conditions are tight and where soil volume and tree opening needs have been met, additional budget may be directed to a ‘hard’ tree guard. T he budget for removal of the tree guard must also be figured in. If the tree achieves the expected growth advocated for in these new standards, the tree tr unk will be larger than the grate. Tree protection is only required for the first t wo years of the trees establishment as long as the soil is sufficient to get the tree off to a good start. After this point, the bark is tough enough to withstand knocks with no detriment to its health.

37

Metal tree guard restricts tree trunk grow th.


5.3 Water Soil below the pavement is only as effective as its ability

from large rain events can continue o n into the traditional

to hold water in the soil. A tree is ef fectively a large pump drawing all available water out of the soil. Soil volume

storm sewer system.

calculations are based, in part, on capacity to hold sufficient water to support the tree between rain events.

Part of the cleaning of the first flush, includes large particulate matter, everything from cigarettes and candy

Toronto has enough summer rains to support trees without active irrigation. Newly planted trees do ne ed

wrappers, to sand, silts and leaves, seeds and plant parts. Even a relatively “clean” retail sidewalk maintains

additional watering, but within a few years they will be self-sufficient.

a constant flow of debris that washes off the pavement with each rain event. The rain har vesting system must

One of the great benefits of large soil volumes is the

be designed to intercept this flow and allow easy clean up for any traps and strainers provided. The debris must

soil’s improved ability to filter, soak up water and r estore some natural cycle functions to urban streets. Harvesting

be intercepted so that it does not clog the rainwater distribution system where it would be difficult to re move.

runoff and directing it into the soil volume provides the additional watering that newly planted trees require to get

The traps must be ea sy to clean and large enough to not require frequent cleaning. Even annual cleaning

established. It also reduces runoff surges on downstream

of these systems may be too much to expect. The

waterways and Lake Ontario.

system, channels, inlets and pipes must be r obust and contain redundant pathways. Cleanouts throughout the

The rainwater harvesting system must collect the first

system are critical. The technical aspects of the design

flush of the rain. Not only is this the most important part of the rain event from a treatment per spective, but many

must take precedence over aesthetic considerations. The responsibility for maintaining this system must be

rain events are small and capturing this smaller an d more frequent rain event provides an even flow of water for

determined and put in the budget. T hese aspects of the water harvesting approach have been significantly under

the tree. After the first flush, the remainder of the water

estimated at both the design and operations levels on

Illustration of water-harvesting of sidewalk runoff.

38


most past projects.

water applications. Heavier loam soils, including most

The type of soil placed u nder the pavement and the

harvested local soils, need water less frequently as they have good water holding capacity, but can also become

amount of soil volume has a big impact on the amount and frequency of water that needs to be added or may

waterlogged if too much water is applied.

also limit the amount of water that can be r eceived by the soil volume. Larger soil volumes ne ed and can

Options to bringing water into soil include pressur ized irrigation, bubbler activated passive irrigation, sur face

accept larger amount of water. Sandy soils, sand bas ed

water harvesting systems that direct water into rills,

soil mixes and bioretention soils can accept larger

trench drains or inlets, pervious paving, and hybrid

volumes of water but need regular infusio ns of water to support tree roots as they tend to be fairly dry between

systems that combine parts of each approach.

A pa ssi ve ir rig atio n sys tem w ith mult ipl e ac ces s po int s.

39


Pressurized irrigation

planting soil. The lines function by gravity to provide even

Standard drip irrigation lines r un under the pavement.

water distribution and getting the hydrology bet ween the pipes and soil is critical. Rigid pipes with the h oles near

This is quite typical for privately maintained landscapes; however,, these systems need significant amounts of however

the top of the pipe are best as water can flow down the length of the pipe to spread the water evenly around the

maintenance. The drip emitters can become clogged and the lines periodically need to be replaced. T he

planting soil. Maintenance of the main line and bubblers is made easier as the bubbler and the valve connections

system needs to be winterized and replacing clogged or

are all accessible inside the box. Winterization and other maintenance are still required. This type of system may

broken drip lines under the pavement is impossible. Due to this concern and City’s limited budget they are not recommended.

be appropriate for projects with suf ficient maintenance

Bubbler activated passive irrigation

Surface water harvesting

Perforated lines used for drainage can be set under the pavement within the soil. These are then connec ted to

Water flowing across the paving surface is co llected in a rill, trench drain or inlet and directed into perforated

a box within the pavement where a pressurized bubbler can be activated to let water flow from the box into

pipes set within the soil. The system must be designed to capture the first flush of each rain event. As with the

the perforated lines where the water infiltrates into the

bubbler activated system, pipe and soil hydrology is

T he he ca ca tc tc h b as as in in is is in in st st al al le le d t hr hr ou ou gh gh th th e n ot ot ch ch ed ed pr pr ec ec as as t c on on cr cr et et e s la la bs bs .

and budget to ensure operation.

P re re ca ca st st co co nc nc re re te te do do ub ub le le re re gl gl et et is is in in st st al al le le d o n t op op of of precast slab and takes water water into wide catch basin.

40


critical. The water must also pas s through a sediment-

by the water must be replaced after cleaning. A strip of

capturing device before entering the pipes under the pavement. This device can be a simple drop inlet with the

pervious pavers within the space bet ween trees over the soil zone can harvest most of the water needed by

outfall set higher than the bottom. The larger the inlet the greater the frequency between maintenance to r emove

the tree. Pervious paving is not currently in wide use and education on its benefits an d use would increase its

sediment and debris. This is the recommended option when pervious paving is not an option.

acceptance. Hybrid systems

Pervious paving

Bubbler activated irrigation, surface water harvesting Pervious paving offer s a low to no maintenance and reliable way to harvest runoff water water.. It only works where

and pervious paving can be used in combination to provide more reliable watering to the soil below the

there is no concrete base to the pavers. When it rains, sediment and debris wash over the paving and into the

pavement. The hybrid approach provides redundancy that permits one system to take over if another part of the

City storm system. Per vious paving will slowly clog but it never reaches the point where no water reache s the soil

assembly fails or slows down water intake volumes. The pressurized bubbler part of the system can be retained

below. As joints clog, they can be cleaned and perio dic pressure washing of pavements is suf ficient to keep

for drought periods; assuming that there are sufficient maintenance procedures to know that the system exists

the system operational. Joint filler material washed out

and could be activated.

The Th e cat catch ch bas basin in is in inst stal alled led wi with th th the e rei reinf nfor orci cing ng st steel eel,, pri prior or to pou pouri ring ng th the e con concr cret ete. e.

Too ooled led dou double ble re regl glet et in into to cas castt-in in-pl -plac ace e concrete takes water into a catch b asin.

41


5.4 Root Zone ID To maintain healthy trees, it is vital that the trees and their root zones are indicated in the same databases that contractors access in order to understand sub-surface conditions prior to repair work. This report recommends that the tree zones be mapped onto the TPUCC digital CADD database. Trees and their root zones would be locatable to both repair crews via the One-call system, and designers/engineers working on street retrofits. This would also give the utility companies a ‘heads up’ if there is a need to contact Toronto’s Urban Forestry Department in order to assist in tree removal. An ide identif ntif yin ying g mark m arker er disk is p rop ose d that t hat woul d be placed flush to the finished grade and directly adjacent to the tree. The disk would identify the method of pavement support above the root zone, which the contractor can use to determine methods for access and repair.

One root zone ID marker should be installed by every tree.

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6. Horticultural Hort icultural Elements Healthy,, mature urban street trees begin with healthy tree Healthy

6.3 Tree Maintenance: Healthy street trees must be

stock with good form and the right growing medium.

continually maintained for structurally optimal grow th and to avoid falling prey to pests.

Guidelines for these practices are described in this section of the repor t and detailed in the drawings and specifications in the appendices.

n umber er of pro s and a nd 6.4 Tree Species Suitability List : A numb cons must be considered when selecting tree species for planting.

Topics discussed in this section include: 6.5 Growing Medium : Trees must be planted in the 6.1 6. 1 Nursery Stock Quality : At the nurser y, quality

appropriate mix of topsoil, coarse sand and compost.

trees suitable for street planting must be selected. It is

Existing soil resources may also be present and put to use for new tree planting.

important to be able to identif y early signs of ill-health in nursery trees.

6.6 Tree Preservation: In retrofit situations, existing 6.2 Tree Installation: There are a number of

considerations related to the timing and techniques associated with planting.

43

trees that merit preservation should be saved with careful planning and correct tree preservation techniques.

Tree Planting Solutions for Hard Boulevard Surfaces Best Practices Manual / Horticultural Practices

6.1 Nursery Stock Quality Quality nursery stock is the first step in growing healthy, mature street trees. D efects in initial tree quality can impact health far into the future, future, reducing life expectancy and causing significant maintenance problems several decades after planting. Quality must be determined for the tree canopy, trunk and root system. In addition to basic tree quality, other issues related to root ball package types such as when and how the tree is harvested, stored, and transported must be specified to ensure that the resulting tree is ready to develop into the mature specimen intended. It is critical to inspect trees in the nursery to ensure quality stock will be delivered to the project. T he chart below outlines desirable and undesirable characteristics in tree selection at the nursery. Rejected nursery trees with poor branching structure and no central leader. Deeper root system in contact with less soil oxygen Lost root system

Nursery tree with unacceptable root ball

44


Root ball as harvested Correct ANLA root ball position

Re j e c te d n u r s e r y t re e s w i t h J - ro ot .

R e j e c t e d n u r s e r y t r e e s w i t h g i r d l i n g a n d a d ve n t i t i o u s r o o t s .

Ch ar a ct er i st ic

A c cept

R eje ct

Canopy

• • •

Single central leader Straight, vertical and tapering Central bud at highest part of tree

• • •

Co-dominant stems Main stem is lopsided, unbalanced or headed Unstable and will split apart

Branch attachment

•

Strong branch attachments

• •

Sharp angles between branch and trunk Too many branches to prune without compromising compromisi ng overall form Branches might break off

• Stakes and ties

•

At harv esti esting, ng, all stak es a nd t ies removed

•

Stakes and ties not removed. Ties can become embedded in the bark. Stakes too close to the trunk at the soil line can deform the future trunk flare.

Health

•

No wounds, insects or disease

•

Trees with wounds, insects or disease such as bores, sunscald cracks or frost cracks on trunk.

Grafted trees

•

The graft and developing trunk flare is visible at time of harvesting.

•

Buried graft points that force the trunk flare to be deep in the root ball Young branches suckering from rootstock below the graft

• Root flare

• •

• • Roots

• • • • •

45

Visi ble root flare at s oil level Visible Remove all excess soil above the root flare and near top of main roots before harvesting Any adve adventit ntit ious root roots s ab ove the trun k flare should be removed Consistent root flare around circumference

•

Roots radiate evenly around main stem Balled and burlapped (B&B) trees with jute and biode grad gradable able twin twine e Wire basket removed from top 300 mm of top of root ball Burlap tied around trunk should be removed Bare root trees

• • •

•

•

Buried flare within root ball are susceptible to form girdling roots and strangle the tree Adventit Adve ntit ious root s ab ove trun k flare f lare that grow in circular or semi-circular form

Asym metr metrical ical root arch architect itect ure J-roots where roots come out on one side T-roots where roots come out of trunk in 2 opposite directions Container grown trees have significant root structure issues that cannot be resolved


6.2 Tree Installation Proper plant material installation is one of the most

London planetree, and others, perform better when

critical elements of successful tree establishment and long-term survival.

transplanted in the spring.

The following factors must be cons idered during the

Ideally, project schedules should take the appropriate planting season for the propo sed plant material into

installation of plant materials. Implementation of the best practices outlined below will significantly increase the

consideration to ensure that the likelihood of tree survival is improved. If schedules a re inflexible, smaller planting

likelihood of successful establishment and long-term tree

stock or larger r oot ball to caliper ratios may increase the

survival.

chances of survival.

In addition to general planting site constraints (soil quality, soil volume, drainage, above- and below-g round

Plant material transportation, handling and irrigation

conflicts, etc.), there are additional factors which must be considered prior to, during, an d following the installation

Plant material is fragile, and must be handled accordingly.

of plant materials. These include:

maintain root ball integrity, prevent stem scarring, and reduce the likelihood of plant tissue dessication. Trees

• Root pruning • Season of planting

should therefore be thoroughly irrigated at the nursery prior to shipping, should be shipped in clos ed trucks

• Plant material transportation and handling • Planting hole preparation

or with foliage wrapped to reduce evapotranspiration, and should be kept out of direct su nlight until planting.

• Backfilling and irrigation • Staking/guying

Addi tio tional nally, ly, tr ees sho uld not be r oll olled ed on the their ir roo t balls b alls (to prevent cracking), and should never be lifted by the

The overall objectives of handling planting stock are to

trunk or dropped. These factors notwithstanding, the majority of failed plantings result from one or more of three key factors:

If trees are to be held on -site for an extended period

planting too deep, and under- or over-w over-watering. atering. If h ealthy ealthy,,

of time (exceeding two hours), they should be regularly irrigated. The holding area should be sheltered from both

site-appropriate trees are planted at the co rrect depth higher chance of success.

sun and wind. If B&B tre es are to be held on-site, the ro ot balls should be covered by soil, mulch or similar medium

Root pruning

to help prevent dessication. Bare-root root systems should be similarly treated, and application of anti-

and are properly irr igated, the plantings will stand a much

desiccant foliar sprays may be required. Trees 150 150 mm or larger may benefit from having been root pruned at least one growing season prior

Planting hole preparation

to harvesting. After root pruning the trees will need additional water. water. Better grower s will do this as part of

Proper preparation of the planting hole will have a

their normal practice. To ensure that this is under taken,

significant effect upon the o utcome of tree installation, and must take into account characteristics of the site

large trees should be pre-purchased at least one year in advance and arrangements with the grower made to root

soils.

prune and maintain the trees. Season of planting

In well-drained soils, the planting hole should be dug to a depth not exceeding or slightly shallower than the

In general, trees should be planted in early spring or

height of the root ball. Planting the tree too deep will deprive the root system of oxygen, prevent gas exchange,

fall, thereby avoiding periods of active shoot elongation

and restrict water. The bottom of the hole should be

when roots may grow poorly. However, a number of

undisturbed; if disturbed, soil should be fir mly tamped

tree species, including most oaks, red and silver maple,

to prevent root ball subsidence. The hole should be dug

46


as wide as possible, and at least three times the root ball

available, and selection of the proper system will be site-

diameter. The sides of the planting ho le should be sloped diameter. and scarified. The tree should be installed so that the

and species-dependent. A ll trees, however, should be tied to stakes using flexible and soft materials such as

top roots in the root ball are just below the soil surface; this may require removal (by hand) of some soil fr om the

rubber or elastic webbing. Hose-wrapped wire should not be used. Most an choring systems should be removed

root ball. The trunk flar e should be set slightly above final grade.

within one year following planting, unless trees are planted in poorly-drained or highly sandy soils which may

Backfilling and irrigation

inhibit the rapid development of strong anchor ro ots or a firm root/soil interface. Where appropriate, staking should be avoided altogether.

Backfill soil should be loose an d friable, with most large clods of soil being broken up. Some s oil clods (also called ‘peds’) should be retained to provide pore space and improved soil structure. Backfill soil sh ould be lightly tamped by foot once one-h alf of the planting hole is filled, and should be irrigated to eliminate air pockets

Trunk support staking may be required when smallcaliper or poorly-developed trees a re to be planted. It is always preferable to avoid planting tree s with weak or poorly-developed stems, but w hen such planting is required, support stakes should be installed. These

and provide moisture. The remainder of the planting hole should then be filled, without adding soil to the top of the

stakes should be installed to the lowest point necessary

root ball. In well-drained soils, a 25 to 40 mm high saucer

the trunk using soft webbing or similar materials.

to hold the tree upright, and should be installed close to

of soil should be formed arou nd the edge of the root ball. Mulch should be added on top of and ar ound the root ball

All anc anchor hor and sup suppor por t s tak ing mus mustt be b e remo r emoved ved in a

to a depth not exceeding 80 mm, and set a minimum of 40 mm away from the root flare/trunk.

timely manner, or the newly-planted trees risk being girdled or otherwise deformed.

Following planting, the root ball should be thoroughly irrigated; irrigating too quickly and for too short a period of time may not allow water to adequately penetrate the root ball. Staking/guying

Staking or guying can be used for two purposes: to anchor an unstable root ball, and to support a weak trunk. The objective of anchor staking is to prevent root ball rotation, which can lead to newly-planted trees falling over and can prevent proper root development. A nchor staking is usually achieved by driving two or more wooden stakes or metal posts into the ground and tying the tree to the stake. Stakes should be installed so that the root ball is firmly suppor ted while allowing the trunk to move slightly. slightly. This encourage s strengthening of the trunk, as the tree compensates for inherent weaknesses by developing wood where required. A numb n umber er of d iff iffere ere nt anc anchor hor sta kin g sy ste stems ms are

47


6.3 Tree Tree Maintenance Mai ntenance Four key horticultural elements mus t be taken into

establishment. Trees planted in mid-summer should

consideration following proper planting and mulching. These include:

be watered daily for at least one week, and then on the schedule outlined previously. Periods of drought may

• Watering • Pruning • Fertilization • Pest, disease and competition control

necessitate more frequent watering for spring or fallplanted trees. Larger trees may require watering every other day for up to three months, and container-grown trees may have a longer establishment per iod than fieldgrown, B&B trees. Properly hardened-off field-grown trees may require less-frequent watering for less time.

Watering

Trees should be irrigated such that soil is kept moist at Planted trees require supplemental irrigation until they become successfully established, at which time natural rainfall should be sufficient to supply the water needs of trees planted in good sites. In the Toronto region, the establishment period t ypically lasts approximately 12 months for every 2.5 cm of trunk diameter at time of planting. Container-grown trees often take one or two

nearly all times, but complete soil saturation should be avoided. There is no ‘right amount’ of water to apply, but as a general r ule a tree in well-drained soil should receive between four and eight litres of water per 2.5 cm trunk diameter at each irrigation. The exact amount will vary depending on soil drainage and other site-specific requirements.

months longer to establish than field-grown transplants. Container-grown trees are not recommended and should

A simp s imple le test t est to d eter mine soi soill mois m oistur tur e co nten t can c an be

not be planted.

conducted by squeezing a handful of root ball soil. If

The critical zone for irrigation is the newly-planted tree’s

water drips from the soil ball, water volume should be reduced. If the soil crumbles, water volume should be

root ball. Irrigating surrounding soils is not necessary and can in fact be counter-productive. Adequate

increased. Ideally, the soil should s tay together. Root ball moisture content can also be felt by inser ting a finger into

supplemental irrigation of the root ball encourages

the root ball.

establishment by increasing the rate of root development, especially root penetration out of the root ball and into

Pruning

surrounding landscape soils. Irrigation is absolutely critical to the success of tree

Newly-planted trees should not be pruned to ‘compensate’ for root loss due to trans planting, as such

plantings. If irrigation is cut off before establishment,

pruning is ineffective and may in fact slow ro ot growth.

the likelihood of tree mortality is substantially increased. Conversely, overabundant irrigation, especially in poorly

However,, young tree pruning should be undertaken to However

drained clay or compacted soils, can es sentially drown roots by depriving them of gas and nutrient exchange

promote good canopy structure, particularly for trees

capacity.

habit. Pruning should be undertaken at least 3 times

Proper watering needs to consider the irrigation system, the

within the first 10 to 15 years following planting, and more if required. The focus of such pruning should be

timing of watering, and the amount of water provided. Until the establishment period, trees should be watered using slow

to eliminate or prevent poor structural con ditions such as included bark, co-dominant stems or sprouts, or to

water emission devices, such as gator bags or root zone irrigation inlets.

remove broken, dead, diseased, badly injured or infested branches. Young trees should be trained to develop a

In general, trees planted in ear ly spring or fall will

central leader, if possible, although some species will not respond well to such pruning due to their natural form.

require watering every other day for approximately 1-2 months, with subsequent once -weekly watering until

48

with a natural decurrent (rounded and spreading) growth

Training should also be undertaken to encourage and maintain appropriate clearance from str uctures and over


streets and sidewalks. Consideration should be given to retaining temporary branches for two to five years, with the purpose of encouraging good stem taper and

requirements • Select densely-canopied trees to shade out weeds • Design sites for easy maintenance access

protecting the trunk. Site preparation Fertilization

Trees generally do not need to be fer tilized at time of planting. This does not mean, however, that fertilization is never appropriate – the decision to fer tilize should always be supported by a soil fer tility analysis and recommendations of a soil test.

• Remove weeds and cultivate site soils prior to planting • Prepare the site to ensure good drainage • Provide adequate irrigation • Plant new trees properly mulch ch • App ly mul Site maintenance

Pest, Disease and Competition Control

Due to the stresses associated with transplanting, newly-planted trees may be more susceptible to pest

• Monitor and remove weeds regularly throughout the growing season, and remove weeds before they are

competition from other types of vegetation.

well established • Establish thresholds for acceptable weed levels • Maintain adequate mulch levels

Pests and diseases

• Reduce mowing intensity to encourage deeper turfgrass rooting

infestation, disease and pathogen infection, and

Pests and disease problems affecting young trees frequently begin in the nursery before the trees are

Avoi d soil s oil cul cultiva tivatio tion n and a nd edg edging ing in r oot zon zones, es, as it • Avoid causes soil compaction and injures shallow roots

transplanted into the landscape. For this reason, careful inspection of nursery stock before delivery is important to ensure diseased or infested stock is not established. Should newly-planted trees show signs or symptoms of pest infestation or disease, an Integrated Pest Management (IPM) approach should be implemented to control the problem. Competing vegetation

Tree establishment can be delayed and overall tre e health may suffer on sites with competing vegetation, particularly herbaceous weeds and turfgrass. Cultural practices to minimize weed competition should be undertaken when trees are planted in the landscape. As outlined below, strategies to minimize weed competition include proper site design, correc t site preparation and planting, and adequate subsequent maintenance. Site design

• Select hardy and site-adapted species • Group plants with similar cultural, soil an d irrigation

49


6.4 Tree Species Suitability List Different species of trees are suited to different planting typologies, and vary with regard to a number of factors including, among others: • General physiological requirements • Soil moisture and nutrient requirements Adapta ptatio tion n to loc local al clim ate and mic microc roclima lima tes • Ada • Long-term maintenance requirements (e.g., pruning) • Root system characteristics • Canopy form • Pest and disease susceptibility • Pollution tolerance • Fruit and seed production • Invasive potential and ‘weediness’ • Biogenic volatile organic compound (VOC) emissions • Aes the thetic tics s The following chart outlines the general characteristics of tree species suitable for es tablishment within one or more of the tree planting ty pologies within the City of Toronto.. Due to the limited utility of conifer s for most Toronto street tree plantings, only deciduou s trees are included in this list.

50


Tree Selection Char t Botanical

Common

Name

Name

Acer nig nigrum rum

Black maple

S. Ontario

Similar to A. saccharum, S i mil ar to A . s ac c ha r u m potentially more tolerant of difficult sites. Underutilized and uncommon.

OL

16 -25 6.07.5 2

Acer rub rum

Red maple

S. Ontario

Brilliant colour. Hardy cultivars. Generally urban tolerant.

Po o r b r a n ch co n n e c ti o n s

OP, OL

16 -25 <7.2 2

Acer saccha sac cha rin um

Silver maple

S. Ontario

Fast growth. Good colour. Hardy cultivars. Urban tolerant.

Poor branch connections, weak wood, aggres sive roots, heavy seed. Limit use.

OP, OL

16 -25 4.57.0 2

Acer saccha sac cha rum

Sugar maple

S. Ontario

Brilliant colour. Strong wood. Emblematic tree. Dense shade. Some cultivars are more tolerant.

Limited tolerance to urban conditions. Sensitive to heat and drought. Some girdling roots. Some pest issues.

OL

16 -25 5.57.3 2

Acer x Freemanii

Freeman maple

Hybr Hy brid id

Hybr Hy brid id of A. rub rubru rum mx Poor branch attachment A. sacc har harinum. inum. Seve Several ral in some cultivars. cultivars available – Agg res sive root syst Aggres system; em; select appropriate for provide adequate site. Urban tolerant. opening to accommodate Combines both good planting in hard boulevard and bad traits of parent conditions. species.

OP, OL

16 -25 6.87.7 2

Aesc ulu ulus s gla bra

Ohio buckeye

N. Showy flowers. Dense America shade. Visual interest. Under-utilized.

Heavy fruit and messy leaves. Early leaf drop. Toxic. Limit use.

OP *, OL

15 -20 6.17.5 2

Ame lan chie r Amelan canadensis (standard form)

Serviceberry (tree)

S. Ontario

Small tree, also available in shrub form. Good for compact sites. Very show y flower fl ower s. Edible berries attract wildlife.

Strongly prefers moist soils with good drainage. Potential for fire blight.

OP, OL

5 -7

5.67.5 2

Carpinus betu lus lus,, esp. e sp. ‘Fastigata’

European hornbeam

Eur urop ope e

Urban Urba n tole tolera rant nt.. Fastigiate form good for compact sites. Tolerates heavy pruning.

Limited use as street tree due to low branching habit. Poor salt tolerance.

CT, OP, OL

10-15

5.0-8.0

Celtis occidentalis

Common hackberry

S. Ontario

Urban tolerant. Showy bark. Fruit attracts birds. Dense shade. Graceful mature form.

Requires careful pruning for good longterm form. Girdling and surface roots possible. Little decay resistance. Susceptible to mechanical damage.

CT, OP, OL

16-25 6.0-7.8

Cladrastis kent ukea (syn. lutea)

Yellowwood

N. Fairly hardy. Showy America flowers. Moderately drought tolerant.

Requires frequent structural pruning in first 15 years; do not plant if pruning program is not in place. Unpruned trees tend to fall apart within 30 years.

OP, OL

10 -14 6.0-7.8

51

O ri ri gi gi n

G en en er er al al At At tr tr ib ib ut ut es es /

Potential Issues /

Suitable

Comments

Limiting Factors

Locations


Height Range1 (metre)

Ideal pH


Common

O ri ri gi gi n


Potential Issues /

Suitable


Ideal

Name

Name

Comments

Limiting Factors

Locations

Corylus colurna

Turkish hazel, filbert

Europe/ Hardy; urban and Asia Asi a pollution tolerant. Good for smaller spaces.

Few if any issues. Nuts CT, OP, may be unsightly or messy OL to some.

12-15

5.5-8.5

Ginkgo biloba

G i nkg o

Asia

Use named cultivars only to ensure male trees; females develop foulsmelling fruit about 20 years after planting each fall. Prune to develop strong central leader due to tendency for co-dominant stems. Overutilized in some areas.

CT, OP, OL

15-22 5.07.0 2

Gleditsia triacanthos var. inermis

Thornless N. Urban tolerant. Fast honey America growing. Cast light locust shade.

Susceptible to aphids and defoliators. Over-utilized. Only thornless and seedless cultivars should be used. Branches can be brittle. Rarely grows with single leader; pr une to reduce co- dominant stems and tight crotches.

CT, OP, OL

15-22 5.5-8.0

Gymnocladus dioicus

Kentucky coffeetree

S. Urban tolerant. Winter Ontario interest. Almost entirely (limited) pest and disease-free. Relatively rare. Good canopy structure.

Male cultivars are strongly preferred due to unsightly, hard and large seed pods on female trees. Some object to sparse branching in young trees.

CT, OP, OL

15-22 6.0-8.0

Liquidambar styra sty racifl cifl ua

Sweetgum

N. Under-utilized. Good America canopy structure requires little pruning. Interesting fruit and foliage.

Agg res sive root syst Aggres system; em; provide adequate opening to accommodate planting in hard boulevard conditions. Does not tolerate soils above 7.5 pH.

OP *, OL

16 -20 5.57.0 2

Liriodendron tulipifera

Tul ip -t re e

S. Fairly urban tolerant. Ontario Fast- and large-growing. (limited) Good structure. Showy flowers and foliage.

Susceptible to aphids which cause honeydew drop. Aggressive root system; provide adequate opening to accommodate planting in hard boulevard conditions.

OP *, OL

20 -30 4.57.5 2

Nyssa sylva tica var. sylva tica

Black gum, tupelo

S. Fairly urban tolerant. Ontario Good structure. Under(limited) utilized. Good for poorly-drained soils.

Few issues. Low utilization CT*, OP, makes it difficult to find OL and to track progress.

15-20 5.57.0 2

Ur ba n to le r an t . L ig h t shade. Interesting foliage. Pest and disease resistant.

CT – Covered trench

OL – Open landscape

OP – Open planter

* – limited or untested applicability

52


pH


Common

Name

Name

Ostrya virginiana

I r o nwo o d


Potential Issues /

Suitable

Comments

Limiting Factors

Locations

S. Ontario

Urban tolerant. Midsized. Few pests and diseases. Winter interest. Good for birds. Should be utilized more.

Few issues. Salt-sensitive and does not thrive in wet soils.

CT, OP, OL

Phellodendron Amu Amurr amu ren se amuren cork-tree

Asia Asi a

Fairly Fair ly u rban tole ran rantt an d Male cultivars should be OP, OL hardy. Virtually pest and used to avoid messy fruit. disease-free. Potentially invasive. Needs adequate soil volume to be truly urban tolerant. Pruning required for good structure.

Platanus occidentalis

S yc a m o r e

S. Urban tolerant. Visual Ontario interest. Good canopy (limited) form. Prefers moist and will tolerate quite poor soils. Dense shade.

Platanus x acerif ace rifoli olia a

London Euro Eu rope pe plane-tree

Quercus bico lor

Swamp white oak

Quercus mac roc ar macroc arpa pa

B u r o ak

Quercus Chinkapin muehlenb mueh lenberg ergii ii oak

O ri ri gi gi n

Susceptible to several diseases and pests.


Ideal

8-12

4.27.6 2

pH

10 -15 6.0-8.0

CT* (due to spreading roots), OP, OL

20-25 4.96.5 2

Urban Urba n tole tolera rant nt.. Visu Visual al Aggres Agg res sive root syst system; em; interest. Good canopy provide adequate form. Drought tolerant. opening to accommodate More pest and disease planting in hard boulevard tolerant than Sycamore. conditions.

CT* (due to spreading roots), OP, OL

20-25 3.7-8.2 (6.52 for var. ‘Bloodgood’)

S. Ontario (ltd.)

Under-utilized and not tested, but a promising urban tolerant tree. Tolerates wet, compacted soils. Does not tolerate alkaline soils.

As mos mostt oa ks, sus suscept ceptible ible to a number of pests and diseases. Untested in urban areas. Transplant in spring.

CT*, OP, OL

15-20 4.36.5 2

S. Ontario

Urban tolerant. Largegrowing. Visual interest. Good form and strong wood. Drought tolerant and adaptable to a wide range of soils.

Like most oaks, difficult to transplant. Spring planting. Requires ample soil volume to avoid root/ sidewalk conflicts.

CT, OP, OL

20-25 4.57.5 2

S. Ontario (ltd.)

Urban tolerant. Midsized. Well suited for streetscapes. Highly under-utilized and difficult to procure, should be utilized far more frequently. Few pest and disease problems. Adaptable to most soils.

Few issues. Difficult to procure. Spring planting.

CT, OP, OL

12-15

6.5-8 2

1 In optimal growing conditions. Difficult sites often result in shorter trees. 2 Ensure that growing medium pH is acceptabl e for species. The Growing Medium Spe cification that accompanies this report defines the acceptable pH range as 6.0 to 7.8. Where species require less alkaline soil, the pH maximum should be l owered to an appropriate level for those plants. Note that lower pH growing medium will cost more due to to the lack of availability of lower pH components.

53



Common

Name

Name

Quercus plaustr pla ustr is

P in o a k

Quercus rob ur

O ri ri gi gi n


Potential Issues /

Suitable

Comments

Limiting Factors

Locations

N. Urban tolerant in acidic America soils. Good canopy form.

Chlorotic in alkaline soils (>7 pH). Susceptible to several pests and diseases.

OP, OL

15 -20 5.06.5 2

English oak

Eur urop ope e

Winter-persistent leaves can be attractive or a nuisance, depending on perspective. Columnar trees may have poor structure. Large acorns may be problematic.

OP, OL

15 -18 4.57.5 2

Quercus shumar shu mar dii

Shumard oak

N. Urban tolerant. Brilliant America foliage. Under-utilized. Tolerates a wide range of soils; wider than red oak.

Susceptible to gypsy moth and other pests and pathogens, but not sufficiently to preclude its use. Large-growing at maturity. Potentially difficult to procure.

OP, OL

20 -25 5.87.6 2

Robinia pseudoa pse udoa cac cacia ia ‘Purple Robe’ or ‘Frisia’

Black locust

N. Urban tolerant. Showy America and fragrant flowers. Attrac Att ractive tive to polli p ollinato nators. rs. Light shade. Decayresistant wood.

Invasive. Brittle br anches; Invasive. fine twigs can cause litter. Requires dedicated pruning to form good structure. Use sparingly and only in difficult conditions, avoid planting in open landscapes due to invasive potential. Thorny.

CT, OP

15 -20 4.57.5 2

Sophora japoni jap onica ca

Japanese Asi Asia a pagoda tree, sophora

Requires some pruning to form good structure. Flowers and fruit potentially messy. Unknown invasiveness potential.

CT, OP, OL

15-20 4.5-8.2

Tilia x ‘Redmond’

‘RedN. Urban tolerant. Good mond’ America pyramidal form. Showy basswood – flowers. Vigorous and cultivar more decay-resistant than other lindens. Increasingly common but not over-utilized yet.

Expansive root system. Susceptible to aphids which cause honeydew drop. Occasional suckers at base.

OP, OL

15 -20 4.5-8.5

Urban Urba n tole tolera rant nt.. Adapt able to wide w ide ran range ge of soils and moisture regimes, including drought. Fastigiate and standard forms available. Few pests and diseases.

High ly u rban tole Highly toleran rant. t. Tolerant of heat and drought. Showy flowers after approx 10 years.

CT – Covered trench

OL – Open landscape

OP – Open planter

* – limited or untested applicability

54



Ideal pH


Common

Name

Name

Tilia cordata/ tomentosa

Littleleaf/ silver linden

O ri ri gi gi n

Euro Eu rope pe


Potential Issues /

Suitable

Comments

Limiting Factors

Locations

Urban Urba n tol tolera erant nt,, esp esp.. cordata. Adaptable to a wide range of soils. Moderately droughttolerant.

Generally over-utilized. Susceptible to aphids which cause honeydew drop. Suckers at base when stressed. Tendency to form co-dominant stems; requires early pruning to provide good structure.

CT (cordata), OP, OL


Ideal pH

15-20 6.5-8.2 (cordata) / 6.2-7.2 (tomentosa)

Ulmus ame ric ricana ana cvs.

White elm cultivars

S. Urban tolerant. Graceful All U. am eri ericana cana cult cultivar ivar s Ontario form reminiscent of are still susceptible to -cultivars stately elms which DED to some degree, once dominated and to other pests and urban forests. Strong pathogens. Ex tensive wood. Adaptable to shallow root system a wide range of soils. requires space. Limit Cultivars such as ‘New use due to DED, but Harmony’, ‘Liberty’, and use where hardy trees ‘Valley Forge’ appear are necessary in small to have some Dutch numbers. Requires early Elm Disease (DED) pruning to develop good resistance. form and strong canopy.

CT*, OP, OL

20-30 5.5-8.0 (varies by cultivar)

Ulmus hybr ids

Elm hybrids

Varie s Varies (typ. Asia) Asi a)

Zelk ova Zelkova ser rat a

Japanese Asi Asia a zelkova

Urban tolerant. A range of more DEDresistant elm hybrids are available, incl. ‘Accolade’, ‘Cathedral’, ‘Homestead’, etc. Wide variety in canopy shapes, from typical vase-shape to more rounded. Adaptable to wide range of soils.

DED resistance of all cultivars is not longterm tested. Some have aggressive root systems. Require early pruning to develop good form and strong canopy.

CT, OP, OL

18-22 Varies

Urba n toler to lerant. ant. Simi Similar lar in form to graceful U. americana, but shorter and more rounded. ‘Green Vase’ is closest. Adapt able to most m ost soil types and moisture regimes. Almost pestfree. Should be planted in difficult spaces more often. Potentially largegrowing.

Branches form in whorls around main stem; require pruning to select best branches and form good canopy. Subject to canker if injured/wounded. Potential for branch breakage if branches too large.

CT, OP, OL

15-22 5.57.5 2

1 In optimal growing conditions. Difficult sites often result in shorter trees. 2 Ensure that growing medium pH is acceptabl e for species. The Growing Medium Spe cification that accompanies this report defines the acceptable pH range as 6.0 to 7.8. Where species require less alkaline soil, the pH maximum should be l owered to an appropriate level for those plants. Note that lower pH growing medium will cost more due to to the lack of availability of lower pH components.

55


6.5 Growing Medium Growing medium quality and volume are a cr itical

Agr icu icultu ltural ral soi soill la bs sif t the t he gra gravel vel out of t he sam ple

component to growing healthy mature trees. Soil to support trees must exhibit physical, chemical and

before determining the % of each par ticle. The gravel is reported separately and o nly if requested. Gravel and

biological properties suitable for tree growth. Soil volume must be sufficient to support the desired canopy

other inert o bjects should never be more than 8% of the total soil sample.

size. Finally soil sources must be factored into the requirements of any soil design.

The size of sand in soil varies fro m 0.05 mm to 2.0 mm. Sand larger than 0. 25 mm is considered medium to coarse sand. These larger sand sizes contribute to

Physical properties

improving drainage in soil. Agricultural soil labs also do not report different sand particle sizes. Special testing is

The physical properties of soil include texture, structure, profile, density and drainage. Th e following are the

required to make this determination. Natural soils in the Toronto area generally have mostly finer sands.

physical properties requirements for a healthy soil to support urban trees. Texture

While the above soil types are ideal for existing s oil, once these soils are heavily graded or compacted they tend

Soil texture is expressed in the no menclature of the soil

to become less usable for tree rooting due to increased density and loss of structure. Sandy loam soil with

texture triangle. Generally loam, s andy loam, sandy clay

the majority of the san d medium to coarse in size are

loam and silty loam soils are the best soils to support tree growth provided they are in a fairly narrow area of

considered the best soil in urban areas to import into new

the center portion of the textural triangle.

region, often manufactured s oil blends are created to

planting beds. Because these so ils are rare in the Toronto

Structure Clumps / clods peds

Density

AI R AIR + WATER +

weight / volume pore space

Texture

HEALTHY

sand / silt / clay

Soil Organisms Organic matter Carbon

Nutrients NPK+

pH Acidity

56


= GROWING MEDIUM

within the peds. Small spaces called micro po res hold water in capillary action. This water is w hat the plant roots use. Large spaces called macro pores are the critical pathways for air, water and soil biology. Understanding soil structure is critical to understanding soil quality, but structure cannot be tested, it can only be observed in the soil. Maintaining s oil peds to the greatest extent possible is critical when working with soil. Profile

Natural soils generally change in qualit y with depth and often layers of different soils can be identified in a section Loamy growing medium mix with peds is desir able.

cut into the soil. The upper layers (called horizons) of so il are normally higher in or ganic content and have strong structure. The soil generally changes colour with depth becoming lighter and less brown the deeper in the profile one digs. The brown colour is reflecting the staining of the soil particles with orga nic matter. Generally the darker the color the greater the amou nt of organic matter. The upper layer of browner soil is called the A horizon and is often referred to as topsoil. A bove the A horizon may be a layer of decomposing organic mat ter such as leaves or other decaying plant matter. This layer is referred to as the O horizon. Topsoil is a much abused and ill-defined term and great care should be used when including it in a specification. Below the A horizon is u sually different layers including the B horizon which is a similar material to the A horizon but with distinctly les s organic matter.

Sandy growing medium mix without peds ( i.e. screened) should be rejected.

provide the needed coarse fraction sand. Coarse sand is

Layers with different colours and texture further down are labeled as various C horizons and normally represent the original parent soil material that has not been significantly influenced by organic activit y.

added to natural soils to improve the drainage. Normally compost is also added to the mix to increase soil organic

Soil in urban areas also has profiles, but these profiles

matter. Soil mixes are discussed separately below.

have been modified by development with the natural soil buried or moved around. In natur al soils, the sequence

Structure

of soil profiles generally contribute to the movement of water up and down to create good soil moisture levels for

Soil particles stick together forming larger structures

trees. In urban areas, modified layers often alter or stop

known as “peds.” The glue that holds them together are

the movement of water.

clays, fungi and organic glue created by soil biology. Over very long periods of time, freeze thaw, wetting and drying, soil organisms, root action and other forces

It is critical when purchasing soil, evaluating existing soils for reuse or c onstructing new planting soil beds to

create a diversity of spaces and fr acture lines within the

consider soil profiles and their impact o n soil quality and

soil mass. Two sizes of spaces are created between and

the movement of water water..

57


measured in the field, however, however, soil can be tested in the

Density

lab if it is compacted to a prescribed dens ity. Natural soil, particularly the upper horizons have a density that permits the flow of water and air into the soil and allows roots to force their way throug h the soil

In constructed planting beds, the drainage rate of each soil layer in the profile must be specified. If the s oil in the

mass. Soil density is expressed in dry weight divided by volume (g/cm 3 or kg/m3 ). T he upp upper er limi ts of s oil den densit sit y

lower layer is too slow, water can become trapped in the upper soil layer even if the upper soil is rapidly draining.

that are limiting to root penetration change with soil type

One way to help move soil across this barrier is to till

with sandy loam becoming ro ot limiting at approximately

the lower soil before adding the upper soil to make a

3

3

1.65 g/cm and silty loam s oils approximately 1.45 1.45 g/cm . Soil density increases when soil structure is lost due to

transition zone between the t wo layers. Alternatively drain lines can be added in the bottom of the upper soil layer to

grading and or physical compaction. When construction disrupts the soil, it compresses the macro pores between

drain away the excess water.

the soil particles, which reduces drainage and air exchange.

Chemical properties

Plants need minimum levels of cr itical nutrients available Soil when being placed in a planting bed ca n also be installed at too low a density. Loose soil will set tle and

in the soil in order to grow. These chemicals are generally present in the soil but may not be in a chemical form that

can cause trees to settle out of position or become

the plant can uptake. In nature, soil biology processes nutrients and converts them into plant available

unstable. Loose soil around root balls can hold excessive

substances. These che micals can also be added in the form of fertilizer when they are deficient. Soil can also

water or drain too fast. S ettlement can cause soil levels to drop below adjacent paving edges creating tripping hazards or trapping surface water. It is generally best

be over fertilized. Fertilizer should never be added to

to install any soil higher than desired an d allow some natural settlement rather than trying to compact it to an

soil without first tak ing a soil test to determine what

optimum density where no s oil settlement will occur. This mounding should be approximately 25 mm for each 250

application rates.

mm of soil depth.

Fertilizer rates recommended for agricultural uses including nursery production are normally too high

Testing density must be performed in the field on

for urban trees whe re slightly lower application rates may be better. Lower fertilizer rates may reduce the

is needed. The soil test s hould include recommended

undisturbed samples using special equipment. The recommended optimum soil density for natural harvested soil to be used for planting is bet ween 1.5 and 1.6 1.6 g/cm for sandy loam and bet ween 1.35 and 1.45 1.45 g/cm3 silty

3

incidence of some disease and insect infestations. Over fertilization also produces chemical rich runoff that enters streams and ultimately Lake Ontario, causing significant

loam. Density for soil mixes will be discussed below.

environmental impacts. Optimizing the s oil’s biological properties, as discussed below, is typically the best way

Drainage

to optimize the soil’s chemical properties.

It is critical to move water into the soil during rain events,

Given that much of the soil urban tr ees will access

and also to ensure that the water can drain out after the rain such that the macro pores are filled with air but

is under pavements and ultimately inaccessible to maintenance, it is important to get the correct chemical

not so dry that there is not sufficient water in the micro pores. Soil texture, structure, density and the amount of

balance in the soil at the time of constr uction of any soil system. Most of the required chemicals ne eded by trees

organic matter in the soil all play a r ole in drainage rates.

are available in sufficient quantities for the life of the tree. Nitrogen is the one element that is not found in soil as

Drainage rates of between 12 mm and 75 mm per hour are considered optimum. Drainage rates must be

a mineral, but is in the air in the soil, constantly being

58

replaced as the soil breathes. Soil organisms process this


nitrogen into plant available form.

system even when surrounded by pavement.

A crit c rit ica icall pa rt of s oil che chemis mistr tr y is i s soil s oil pH or the leve levell of

Elevated soil pH, poor drainage, compaction, and

soil acidity/alkalinity. acidity/alkalinity. Soil pH controls the soils ability to uptake the nutrients in the soil. If the soil pH is either too

excessive fertilizer can reduce microbial populations. Increasing soil organic mat ter can improve soil

low or too high the plant may show chemical deficiencies even though the soil test may indicate that there is

organisms. Use of compos t teas on the soil in conjunction with adding compost has be en shown to

sufficient soil nutrients. Higher pH, above 7.5 7.5 causes the

make improvements, however this approach requires

greatest problems in urban s oils. The Toronto area soils

access to the soil, which is dif ficult in any soil systems

are typically higher than 7.5. It is advisable to use trees that are tolerant of high pH soils rather than trying to

below paving.

adjust the soil pH.

Soil organic matter is measured as a percent of the total

The growing medium specification that accompanies this

dry weight of the soil sample. Soil organic matter should be between 3 and 5% dry weight in the upper layer of

report allow for a pH range of 6.0 to 7.8. The tree species list in this section provides ideal pH rang es. Ensure that

the profile at the time the soil is installed. Or ganic matter in the lower soil level should be between 1.5 and 3% dry

the tree species selected is suitable for the soil pH.

weight. This difference can be accomplished by making two different soils or simply tilling additional compost into

Salt in the soil has a neg ative impact on the plants ability to uptake water. This salt, however, must be present

the surface of the soil.

during the growing period of the tree. In Toronto, winter applied salt frequently washes out of the upper level of

Soil volume

the soil during early spring rains. Observations in the city

The recommended soil volume to grow lar ge healthy

indicate that trees that have sufficient soil drainage and large soil volumes are not af fected by winter salt.

urban trees is 30 m 3 when the tree is alone in a soil bed. In tree groupings with shared soil, 20 m 3 per tree

Biological properties

is recommended. Soil resour ces may also exist on site and can be used to reach the desired soil volume. See Section 2 of the report.

All sur fac face e soils s oils con tai tain n some s ome leve levell of org ani anisms sms that are part of an interconnected web of life, the soil food web. This diverse and complex set of organism s process

Soil sources

the chemicals that plants use as well as building soil

The soil in the Toronto area is mostly silty loam with

structure, increasing drainage and lowering soil density.

very fine sand. There are variations and some fine sandy loam soil exists. Coarse s andy loam soil is rare. Fine

These organisms nee d air, water and a source of carbon to survive. The air and water must be able to flow through the soil. Carbon co mes from soil organic mat ter. Decaying plant roots contribute significant amounts of organic matter to the soil. Trees are net contr ibutors to soil organic matter. Most of this organic matter comes directly from the ro ots of the tree and as the tree increases in size, the soil organic matter increases. Less than half of the soils organic mat ter comes from leaves decaying into the soil. Urban trees can s urvive without having additional mulch or compost added to the soil o r allowing leaves to decay into the soil. As long as there is

sands and silts are prone to drain poorly and be selfcompacting. For this reason most natural soils need to have considerable sand added to the soil to make them perform well in the urban environment. The primary source of soil for purchase is ongoing development sites primarily in suburban locations. At these sites, topsoil is harvested and sold for reuse during the construction process. This soil supply is subject to swings in the construction m arket with less supply available when suburban construction slows. Much of

sufficient water, drainage, pore space and initial organic

these soils are purchased by a limited number of planting

matter the tree can become a self-sufficient urban

soil suppliers for proces sing into soil mixes.

59


Growing medium mixes

these peds is very important to the performance of the

The typical growing medium mix for tree planting is a

soil mix. Soils should not be screened or shredded during the collection, handling and processing procedures.

mixture of naturally harvested A and O horizon soil also known as topsoil, coarse sand and compost. The quality

Unfortunately screening and shredding is common in the industry but supplier s are willing to stop this procedure

of these mix components var y significantly over time and from source to source. For this report, three Ontario

when requested. Clumps of root mat, large clumps of soil and even the occasional stone, stick, root or residual

soil suppliers were consulted for pr icing and availability: Gro-Bark (Caledon, ON), Hermanns (Schomberg, ON)

trash that would normally be re moved by screening should be considered acceptable provided that the total

and Earthco Soil Mixtures (Concord, ON). The exact mix proportions will vary depending on the application, the

of such “inert” objects larger than 2 mm in diameter is less than 8% of the total soil volume.

type of soil and the size of the co arse sand fractions. It is important when purchasing soil mixes, that sufficient

The chemical composition of the so il component should

quality control processes be implemented to ensure consistency in the mix. The following are the critical

meet agricultural requirements for fertile field soil. The pH of the soil is probably the most critical chemical factor

aspects of each component.

to consider as pH controls nutrient uptake by plants. In the Toronto area, pH in soils tends to be around 7.0 to 7.8

Soil

or higher than the optimum. S ources of soil with lower pH between 6 and 7.3 7.3 are mor e valuable when they are

The soil component must be harvested from the O and

available.

A hor h orizon izon s of o f a natu ral soi soill be d. T hes e soil s oils s will w ill ty typic pically ally be dark brown and have an organic mat ter content of

Coarse Sand

between 3-8% dry weight when tested by ignition. It is important that the organic matter not be derived from

Coarse sand is nee ded to improve drainage in the soil.

adding compost to a subsoil to make a “ topsoil.” This is relatively easy to discern in the soil sample as piece s of

The amount of coar se to medium-sized sand (0.25 to 2.0

the compost can be observed in the soil. Organic matter

in order to drain fast en ough but still maintain adequate

must be coating the soil par ticles, the result of a long

moisture holding capacity.

mm) in the mix is required to be between 50% and 60%

process of soil biology in the soil. Soil with the highest percent clay should be valued over

Coarse sand is defined as ASTM C-33 coarse concrete sand with 100% passing a 6 mm sieve, no more than

soils with relatively higher levels of silt. Sandy loam soils

12% 12 % passing a 0.25 mm sieve and a fines Modulus index

that consist of primarily fine sands are a poorer quality material to use in a soil mix than so ils with higher clay

of between 2.8 and 3.2. The pH of sand should be 7.0 or lower.

and silt content. This may be counter intuitive but the fine sands tend to slow drainage in the ultimate mix while the

Compost

clay is needed to hold moisture and nutr ients as well as creating stronger peds. Soil texture should be classified

Compost is the result of biological activity breaking

as loam, sandy loam or sandy clay loam with clay content between 15-25%.

down raw organic material such as leaves, bark , wood or agricultural by-products such as manur e, field stubble or food waste. The composting process converts the carbon

Natural soils normally have clumps, clods or pe ds present in the soil when it is dug up and graded. The se peds are the result of weathering, the activity of soil biology and clay sticking soil par ticles together into

in the plant cells to a more stable and useful material in the soil. In the most simplistic view, the longer the material is composted the more stable the carbon when it is added to the soil.

larger aggregates. These aggregates are important to the movement of air and water into the soil. Maintaining

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The material that makes up the feedstock of the compost


pile produces compost that performs differently in the

available in the Toronto areas as described above, a

soil mix. The most co mmon feedstock is yard waste trimmings. This type of compost is best when used as

reasonable mix ratio is the following:

a surface treatment of the top layer of soil. Composted bark material, composted pine bark in particular, is best

Mix component % by volume

used in a soil mix for tre e soils.

Coarse Sand: 45-50% Soil: 40-45%

Good compost should be dark brown to black, the

Compo st: 1212-15 15% %

colour of 70% cocoa dark chocolate. Individual pieces of material in the compost, when broken apart, should be the same colour inside as ou tside. A good way to test the quality of compost is to evaluate its carbon to nitrogen ratio (C/N). Compost should have a C/N ration of 15:1 15:1 to 25:1. 25:1. A second test is the Solvita Matur ity Index test, which measures the rate that car bon dioxide is released from the soil. A Solvita Index of 6 to 8 is considered acceptable compost.

It is beneficial to add some additional compost in the upper layer of planting beds after the s oil is placed. Addi ng 100m m of o f ya rd was waste te c omp ompost ost till tilled ed into the top 100mm of planting soil will create a generous A ho rizon in the mix without fear of set tlement in the deeper soil layers. This final tilling will help reduce any sur face compaction that occurs during project finishing work that inevitably finds contractors walking over or using soil beds as workspace.

But even good compost is far from being similar to the stable humus carbon forms found in soil. This process

Soil installation

takes decades not months. O nce added to the soil, compost continues to break down, shrinking in volume. For this reason it is w ise to limit the amount of compost

As the soi l is ins instal talled, led, the re are seve several ral key poi points nts that

in a soil mix for tree planting. T he compost is primarily there to increase the organic mat ter level in the soil,

layers between planting soils and subsoil; angle of r epose of subsoil supporting structures; planting soil placement;

which was reduced by the addition of the coar se sand to the mix. Compost should be added to the soil mix at a

and planting soil compaction.

rate of approximately 12 - 15% by volume.

Subsoil drainage

Soil Mix Ratio

The soil below the planting soil must dra in adequately

must be followed. These are subsoil drainage; tran sition

and be able to receive excess water from the planting While final soil mix design will vary depen ding on the

soil. Typically it is excess compaction in the subsoil that

types of soil, sand, and compost, and the need for drainage required by the application, there are base

causes poor drainage; particularly in fine-grained loam, clay loam, and silt loam soil. Drainage co nditions must be

soil mix ratios that can be co nsidered. The best way to determine if a soil mix is going to perform correctly

checked prior to placing soil. Unfortunately if the subsoil is not draining adequately it may be too late to add drain

is to test its permeability at the specified maximum anticipated compaction. This is a lab test where a lar ge

lines. Design of planting soils sho uld always allow for the worse case drainage situations.

soil sample is compacted to a known pro ctor density, usually 80% and 85% and then the soils permeability in

Drainage can be improved by loosening the subs oil just

of 25-75 cm/h. This rate is primarily controlled by the

prior to planting soil installation. If this does not solve the problem, drain lines, set in sand beds, and connected to

amount of sand in the mix.

storm sewer inlets, must be installed.

Assum As suming ing that the app applica lica tion is for tre es, wit with h only o nly

Transition layers between planting soils and subsoil

cm/h is measured. Good soils should have a flow rate

minimum amount of storm water allowed to be added to the soil, and the mix is made from typical products

61

The planting soil should not be placed o n a subgrade


that is smooth. The subgrade must be roughened either

A g ood rul e of o f th umb is to s et fin final al s oil gra des 10% or

by dragging the teeth of a back hoe bucket or by using a roto-tiller just prior to the s oil installation. This will aid

more of the total soil depth above the design grade. For example is the soil is placed 750 mm deep provide

in the movement of water from the planting soil into the subsoil.

an additional 75 mm inches of soil mounded above the design grade.

Ang le of re repos pos e of o f s ubs oil su suppo ppo rt ing st stru ruct ctur ures es

Soil is typically placed with a loader and distributed by hand or small equipment. There is a trend to use soil-

Whenever planting soil is to be placed next to compacted

blowing machines to place soil. This equipment breaks

subsoil that is supporting a structure such as a curb or

up important soil peds and damages the soil structure. Soil blowing equipment must never be permitted!

paving edge, the excavation along the structure must be set with an angle of repose away from the structure at an angle appropriate for the type of subgrade material and the expected loading.

Planting soil compaction

Planting soil placement

Planting soil should be compacted to approximately 75-80% Proctor density. Soils start to become root

Planting soil must be placed with suf ficient compaction

limiting at about 85%. Obtaining the required density is difficult as equipment and people move over the soil

to reduce settlement but not over compacted. In areas where soil is to be over 450 mm deep, the s oil needs to be placed in lifts between 30 0 and 450 mm thick and

during the soil placement and planting proces s. The approximate correct soil density is normally achieved

each lift compacted to the specified amount. Even if

with a minimum of effort. A single pass at each lif t by a tracked skid steer or a plate vibrator may be all that is

compacted to the correct amount some soil settlement

needed. Having the soil near optimum moisture content is

must anticipated. Placing unconsolidated soil leaves fairly large amount of soil pores that will gradually fill with soil

critical. Soil that is over compacted must be loo sened to the entire depth.

particles over time. The compos t will continue to shrink.

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6.6 Tree Preservation Preserving existing trees is crucial to maintaining and

Not all trees can or should be preserved

increasing urban forest cano py cover, cover, and should be an important consideration in the development,

In some cases, the overall benefit associated with a

construction, planning and design processes.

project which requires tree r emoval will be greater than the benefit of retaining trees. Trees in poor structural

This section outlines best practices for preserving and working around existing trees, and for retrofitting

condition or health may be a liability, rather than an asset. Tree preservation should focus o n trees which

additional soil volume in proximity to existing trees.

legitimately merit retention, and resources s hould be allocated.

Existing policies Focus on preventing injury

The protection of existing trees is regulated by several existing City of Toronto by-laws and policies. T hese

Tree injury is very difficult to mitigate once it has

include:

occurred; therefore, tree preservation efforts should

City of Toronto Municipal Code:

focus on preventing tree damage and environmental degradation in the tree’s rooting area.

• Chapter 813, Article II: “Trees on Cit y Streets”, which

Impacts are cumulative and long-term

regulates trees located on the Cit y road allowance, and allocates authority for planting, care, maintenance

Construction impacts such as root loss, soil compaction,

and removal of trees to the City; and

and wounding can add up to a situation that is wor se

Protection”, • Chapter 813, Article III: “Private Tree Protection”, which prohibits the injury or destruction (removal) of trees greater than 30 cm DBH without a permit, notwithstanding certain exceptions.

than the sum of its component parts, and even seemingly insignificant impacts can lead to tree mortality in the long term. Alll par Al p ar ti ties es mu must st com mu muni nica cate te ef fe fect ctive ive ly

Tree Protection Policy and Specifications for Construction Near Trees:

Development professionals, including engineers,

Outlines approaches to and specifications for the

landscape architects, arborists, constructors and others involved in the process mu st communicate using clear,

preservation of existing by-law protected trees on

effective and common language and g raphics to ensure

construction sites. Key issues include:

that expectations for tree protection are understood and met. Doing so involves collaboratively creating and

Tree protection zone (TPZ) distances, barriers and

sharing reports, maps, drawings, sections and details

signage;

and ensuring they are carefully reviewed and under stood by all members of the team.

• Site and landscape plan requirements; • Tree removal and relocation;

Planning

• Security deposits; and • Provisions for emergency repairs.

Where tree preservation is an objective, good project design must consider existing trees from the

Tree Preser vation Principles

initial planning stages. If trees ar e considered as an afterthought, the likelihood of successful preservation

In preserving and working around existing trees, several

is significantly diminished. The following are steps to

general principles should guide tree preservation efforts,

effectively plan for tree protection.

both in the planning stages and dur ing implementation.

63


Tree preser vation cannot wait until construction

affect trees.

Projects must be planned and designed with tree

Proposing alternatives or modifications to

preservation in mind, so that all parties involved in the project understand the requirements to successfully

development plans, if required

protect existing trees;

Where existing trees of significant s ize or value may be adversely affected by construction, modifications or alternatives to development plans should be considered

Evaluating the existing tree resource

at an early stage of the design process. Often, relatively Evaluate the species, size, location, health and general condition of existing trees, in order to determine suitability for preservation, required arboricultural

simple and low-cost activities such as relo cation of services or realignment of paved surfaces can make the difference between tree removal and preservation.

maintenance, and ability to withstand potential stresso rs associated with site development.

Specifying required tree/root protection zones (TPZ)

Understanding and assessing likely construction

A tree t ree pro tec tectio tion n zo ne (T PZ) is an are a ar oun ound d a tre e or or group of trees within which site disturbance s such as

impacts

grading, excavation, or other construction activities are During this stage, the project consultant responsible for tree protection (typically an arborist) should have a

not permitted. The appro priate size of a TPZ is difficult

well-developed understanding of the project propo sal,

to determine; a common rule of thumb sugg ests that the area beneath the tree’s canopy (dripline) should be

including the extent of pr oposed grading, excavation,

protected. However, However, this method ca n be problematic,

infrastructure placement, and other factors which may

particularly for trees with narrow canopies or restricted

City of Toronto Policy on Tree Protection Zones

Trunk Diameter (DBH)1

Minimum Protection Distances Required 2 City-Owned and Privat e Trees

Minimum Protection Distances Required Trees in Areas Protected by the Ravine and Natural Feature Protection By-law Whichever of the two is greater:

< 10 cm

1. 2 m

Th e drip lin e4 or 1.2 m

1 0-2 9 cm

1. 8 m

Th e drip lin e o r 3 .6 m

30 3-40 cm

2. 4 m


4 1-5 0 cm

3. 0 m


5 1-6 0 cm

3. 6 m


6 1-7 0 cm

4. 2 m


7 1-8 0 cm

4. 8 m


8 1-9 0 cm

5. 4 m

Th e drip lin e o r 1 0. 8 m

9 1-1 00 cm

6. 0 m

Th e drip lin e o r 1 2. 0 m

> 10 0 c m

6 cm prot ect io n fo r ea ch 1 cm o f dia met e r

12 cm prot ec tio n fo r e ach 1 cm diamet er o r the drip line 5

1

Diameter at breast height (DBH) measurement of tree stem taken at 1.4 metres above the ground.

2

Tree Protection Zone distances are to be measured from the outside edg e of the tree base.

3

Diameter (30 cm) at which trees qualif y for protection under the private tree by-law.

4

The drip line is define d as the area beneath the outer most branch tips of a tree.

5

Converted from ISA Arborists' Certification Study Guide, gene ral guideline for tree protection barri ers of 1 foot of diameter from the stem

for each inch of stem diameter.

64


If trees and TPZs are not appropriately depicted on relevant construction documents, such as grading plans, it is unlikely that they will be considered during site development. Their preservation should be considered a constraint, and must be adequately reflected as such. The centreline of the tree stem (loc ation), the general canopy outline (not a rou nd circle), and the minimum required TPZ size should be located on tree pr otectionrelated plans. Reporting

The above-noted activities and considerations sho uld be summarized in a comprehensive yet concise repor t, made Toronto Toront o Tree Protection Zone (TPZ) warning sign.

rooting zones. If used to pr otect a broadly canopied tree with a wide-spreading root system, this guideline could still enable the removal of mo re than half of the tree’s roots. Some studies have found that healthy, vigorous trees can tolerate the loss of between 30 and 50% of their roots. It must be noted that any depth of excavation has the potential to remove a significant amount of roots. Excavation as deep as 30 cm may be as injuriou s as much deeper excavati excavations. ons. Diameter at breast height (DBH) is used as the foundation for tree protection zone guidelines and specifications in the City of Toronto and most other Canadian municipalities with tree protection requirements. The optimal TPZ will also consider the subject tree’s overall health, condition, and species tolerance for root zone disturbance. Current City g uidelines do not require that these factors be consider ed during the planning of tree protection on construction sites. Tree protection zones should be fenced-in, using solid plywood hoarding or equivalent material. In areas where visibility is a concern, framed construction fencing can be used. Hoarding should be fir mly affixed to the ground to prevent movement by construction equipment or personnel. Identifying trees and TPZs on all relevant documents

65

available to all parties involved in activities w hich may affect trees on the development site. Pre-construction treatments

Several treatments, undert aken prior to site development, can help to improve tree health and potentially increase tolerance to the effects of construction. Among these treatments include: Pruning

Pruning should be undertaken prior to construction activity, if required, in order to reduce the potential for conflict with both planned structures and construction equipment. It is preferable to prune br anches as necessary rather than correct limb fracture after the fact. Pruning must be done by a qualified ar borist, and not by construction personnel. Pruning for clearance purposes should be kept to the minimum required. Structural Maintenance

If required, structural maintenance such as cabling or bracing should be undertaken prior to commencement of construction in or der to reduce the likelihood of failure during site works. Irrigation

Supplemental irrigation should be pr ovided if trees may be drought stressed during construction. Irrigation should be heavy and thoro ugh, and cover the entire tree


protection zone. It may be beneficial to irrigate trees several months in advance of construction to promote tree health during the construction period. Fertilization

Fertilization is rarely required, but should be provided if recommended by a soil analysis. Fer tilizing trees a season prior to construction may be beneficial, but postconstruction fer tilization should be modest if it is applied at all. Pest and Disease Management

Pest and disease issues sho uld be monitored and controlled prior to and during construction, as increased stresses may predispose trees to decline. Of particular importance are defoliating pests, which could stimulate

Mulching added around the base of a mature tree.

flushing of new foliage and cause trees to use stored carbohydrate resources, which should be reserved for replacing roots.

• Limiting the extent of cutting in ro ot zones to prevent

Mulching

App lyin g mulc m ulch h to a de pth of 5 0-100 mm wit within hin the tree protection zone provides a favourable rooting

smothering, trunk decay and soil compaction; • Minimizing changes to drainage patterns in area s where mature trees are present and adapted to current conditions;

environment. Mulching beyond the TPZ can reduce the

• Reducing the construction of grade transitions in

effects of soil compaction.

root loss; • Limiting the extent of fill in root zones to pr event

root zones. Where po ssible, retaining walls should be created to enable the retention of as large a root area

Vegeta Veg eta ti tion on Ret ent io ion/R n/R em emova ova l

as possible. Additionally, steeper grade transitions may enable the retention of larger rooting area, if trees

Vege tation Vegetat ion sho uld be r emov emoved ed pri or to con constr str uct uction ion and the installation of tree protection zones, unless its

are located upslope of the transition.

retention may help protect trees to be retained.

Utilities and services

Design and implementation

A wide w ide ran ge of util ity ser vic vices es may be f oun ound d below b elow-ground in urban areas, including sanitary and storm

A numb n umber er of d esi esign gn pra practi ctices ces can red uce the adve rs rse e

sewers, water services, telecommunications, hydro,

effects of site development on existing trees. These include:

gas, and others. Many factors will affect the location of a specific service relative to other utilities and

Grading

infrastructure, as well as to existing trees. The most common method of utility installation is trenching,

Grading and associated activities cause the most serious and widespread damage to trees, pre dominantly by

particularly when the surrounding area is not being disturbed through recons truction. Trenching can cause

cutting roots and compacting soils. Considerations to

serious injury to existing trees and roots, as they are typically severed and can be damaged well beyond the

reduce grading-related damage include:

inner edge of the trench due to fracturing and tearing.

66


An ef effec fective tive pro ced cedure ure to i nst all util itie s with w ithin in t ree roo t

• Placing heavy-load areas, which require thicker sub-

zones is to trench to the outer limit of the tree’s TPZ, continue with hand-digging, hydraulic or pneumatic

bases, outside of tree protection zones • Wherever possible, utilizing “no-dig” designs by

excavation within the TPZ until roots g reater than 25 mm in diameter are encountered, and then use trenchless installation techniques such as directional boring to route the utilities beneath or beside the tree. T he appropriate

adjusting finish grades such that the pavement surface is above the surrounding grade, with appro priate grade

trenchless method must be determined in consideration of factors such as pipe or conduit diameter, existing site

transitions • Reinforcing the wearing sur face and base layer of paving so that a compacted sub-base is not required to provide structural support

soils, and proximity to trees. An alternative to trenchless

• Using geotextile fabric beneath the pavement section

techniques is to continue trenching using hydraulic or

to protect from displacement into sof t uncompacted

pneumatic excavation, leaving roots intact, and threading

soils

utilities through and between roots. Monitoring, assessment and reporting

If trenching is unavoidable and roots must be removed, proper root pruning prior to trenching is an essential part

Trees affected by construction may be at increased

of effective tree preservation. Roots should be exposed

risk of mortality or failure. Tree mortality can be a

to a minimum depth of 60 cm by hand or u sing hydraulic

gradual, long-term process, and is typically caused by

or pneumatic excavation methods and properly pruned

adverse impacts to the root/soil system. Tree failure

at right angles using a sharp pruning saw. Any damaged roots should also be properly pruned.

(i.e., uprooting or stem fracture) following construction typically occurs as a result of changes in wind dynamics due to site clearing.

Any new abo aboveve- gro und uti utiliti lities es sho should uld be i nst alle d in consideration of the growing requirements of the tree canopy and stem.

An arb or orist ist sho uld be o n-s ite dur during ing and foll owin g construction to asse ss the potential impacts of

Pavement installation

construction and the likelihood that they may contribute to one or both of the mortality patterns described above. Considerations for site and tree inspe ction during and

Pavement installation may have a wide range of effects upon existing trees, ranging from the nearly negligible to causing complete mortality. The primary determinant

following construction include (Coder, 1996):

of the extent of damage is the amount of sub-grade

• Loss of rooting area and general damage to the root system

preparation required to install the pavement; deeper excavation will invariably result in more extensive ro ot

• Damage to the root collar and structural roots • Mechanical injury to the stem

loss, while no-dig de signs may entirely eliminate root damage. Extensive soil compaction is of ten required

• Changes in soil structure such as compaction, fill, erosion or loss of organic matter

to support traditional paving installations – routing pavements outside of tree protection zones will reduce

• Changes to wind loading in the crown

the impacts of sub-base preparation.

• Damage to branches • Decline in overall health • Obstructions

Key factors achieved by the tree planting technical solutions (See Section 4: Sidewalk Arrangements, and App end endix ix A: Con str uct uction ion Dr Drawin awin gs) tha thatt redu r edu ce t he impact of pavement installation on existing trees include: • Using a pavement type with the thinnest po ssible section, which requires less excavation

67

Asses As ses sme nt res ult ults s shou s hou ld b e co mpil ed and pre sen sented ted in a post-construction arborist report. If required, the report should outline required remedial actions such as decompaction, irrigation, mulching, corrective pruning or other requirements.


References

Coder, K. 1996. Construction Damage Assessments: Trees and Sites. Sites. University of Georgia Cooperative Extension Service. Forest Resources Unit. FOR96-39. University of Georgia: Athens, GA. Gilman, E. F. 1997. Trees for Urban and Suburban Landscapes.. Delmar: Albany, NY. Landscapes N. Matheny and J.R. Clark. 1998. Trees and Development: A te chn ica l g uid uide e to pre ser vat vation ion of tre es dur ing la land nd development . International Society of Arboriculture: Champaign, IL. Urban, J. 2008. Up by Roots: Healthy Soils an d Trees in the Bui lt E nvir onm ent . International Society of Arbor Ar bor icul tur ture: e: C ham hampaig paig n, I L.

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7. Demonstration Demonst ration Projects The consultants and the Cit y organized a soil cell

Nashdene Yard Soil Cell installation progre ss photos

testing exercise at the City of Toronto’s Toronto’s Nashdene Yard in Scarborough with utility stakeholders Toronto Water and Enbridge Gas. New utility ins tallation and repair of existing utilities under soil cells was recreated at the Yard: 7.1 Toronto Water utility access exercise : Toronto

Water recreated an “emergency s cenario” in the middle of winter (Feb. 24, 2012). 2012). The scenar io involved bursting a water main and testing the effects of water leak ing on the soil cell system. Soil cell trench filled with soil

7.2 Enbridge Gas lateral line and riser installation:

Enbridge Gas tested access thro ugh soil cells to install a gas lateral line. 7.3 Bloor St. W. at Dovercourt Rd. and Concord Ave. demonstration project : A further on-site demonstration

project was propos ed. However, However, it was decided not to be implemented as part of this study, due to a larger upcoming resurfacing project in the area. Soil cell decking system.

Note: The soil cell product used at Nashdene Yard was Silva Cells, manufactured by DeepRoot Green Infrastructure, LLC.

T E I T S E S C I S R E E X T I F F I E L D R D .

Backfill installation on top of deck.

R D Y A Y T E L I T C I L D E N F A H S N A & R E C S R K P A

D. N E R E D S H N A

Nashdene Yard location, Scarborough.

69

Finished installation.

Tree Planting Solutions for Hard Boulevard Surfaces Best Practices Manual / Demonstration Projects

7.1 Toronto Water Utility Access Exercise Description of the exercise

demonstration sidewalk. After the water valve was shut off, the following activities took place:

The cold weather conditions, at - 4°C (-10°C (-10°C with wind chill) provided Toronto Water field personnel a good test for working with soil cells in adverse conditions. The exercise began at 8:00 am with an on-site briefing where the demonstration project coordinators and

Concrete sidewalk pavement was removed

• Concrete pavement was saw cut into blocks that could later be removed by a backhoe.

Toronto Water Water personnel discusse d the different activities

‘A’ base below • Removal of concrete and granular ‘A’ concrete paving.

and the order of execution. Water was then turned o n

• Crew located a geotextile layer that was installed

into the installed water pipe which was capped on both ends and pre-cut during its installation under the soil

below the granular ‘A ‘A’’ and on top of the soil cell top frame deck; the geotextile was cut to expose the soil

cell system. Water fed from a hydrant at 414 414 kPa ran for approximately three minutes before it started to come

cell deck. • Manual removal of two of six so il cell top decks were

out through the already s aturated soil adjacent to the

set aside for re-installation.

Water pipe cut.

Sawcutting concrete pavement.

Water introduced - water bursting out of saturated soil adjacent to

Mechanical removal of pavement to expose soil cell decking

installation.

system.

70


Manual removal of two decks, unscrewed and set aside for future

Excavation below bottom of soil cells to daylight water pipe.

re-installation.

Me c h a n i c a l re mova l of s o i l c e l l s .

71

E xc avat i o n b e l ow b ot to m o f s o i l c e l l s to d ay l i g ht wa te r p i p e .


Mechanical removal of soil cells, soil a nd sub-base

Conclusions of the Toronto Water exercise

• Backhoe was used to dig ou t and through soil cells

Once the soil cells were removed, the stakeholders

and soil. • Water pipe was daylighted.

discussed the outcome and lessons learned from the exercise. It was concluded that Toronto Water Water can ea sily

Repair

access its infrastructure through the soil cell system under extreme conditions using the same methods they currently have in place in either a planned or emergency

• The dug trench was temporarily repaired afterwards with unshrinkable fill up to finished grade. • Weeks later, unshrinkable fill was broken up to the bottom of the first layer of soil cells to restore the cells

situation. The exercise allayed their concerns that the soil cells would be a hindrance in their field work . Further discussions of a ver tical minimum clearance between the utility and the bottom of the s oil cells are expected.

and surface finishes to the original condition.

STEP 1 Cover sides with a polyethylene film and fill with unshrinkable fill until 50mm below finished surface

STEP 2

Remove top of unshrinkable fill to the level of upper soil cell and restore soil cell trench and surface finishes

72


7.2 Enbridge Gas Lateral Line and Riser Installation Description of the exercise

The exercise began at 9:00 am at Nashdene Yard in Scarborough on a late-May day that was partly cloudy and warm. A gas lateral with a long riser was installed under a sidewalk cross-section of unit paving and soil cells. Using a mole with the shortest torpedo hammerhead at 1 .0 m length, the 25 mm gas line was bored through the growing medium and adjacent subgr ade. Excavation was only necessary at each end of the gas lateral. For longer horizontal drilling, a directional dr ill is used which has greater directional control. Enbridge usually uses a torpedo mo le for downtown work, which

Removal of pavers and granular base.

requires less excavation and can be used for hor izontal drilling through sidewalk cross-sections. It can drill through tree roots and is only blocked by large rocks. The following took place: Setting the direction and start ing point of the horizontal boring

• Mock building and road sides of the s idewalk were designated for the purposes of this exercise. • Unit pavers and granular base were re moved to locate and confirm the cell deck edge. The torpedo was set to drill horizontally between the soil cell frame legs

Geotextile is cut through centre of cell deck.

from the side. • The crew dug down two cells dee p between the building side and the cell, until there was enough roo m to slide the riser through. Where there is not enough room to dig behind the cell, the cell can be removed to install the riser. • In alignment with the pit dug at the building end, another pit was dug down approximately 1.2m deep at the road end of the lateral. Directional boring

•

The torpedo was first set to begin at the building side where the riser would be placed. The torpedo did not make it out at the road side because it had great difficulty going from soft material to hard material (i.e.. growing medium to hard clay subgrade) as it does not have enough friction to propel it forward.

• The torpedo was reset to begin on the road side. It

73

Digging down approximately two cells deep at both lateral ends.


bored through the road subgrade then through the soft growing medium and came out at the building side. Pulling the lateral through, attaching and setting the riser

• The torpedo was removed and the lateral pipe was attached to the hose end and pulled through. • The riser was fus ed to the pipe end and pulled through and set at the corr ect elevation. • Granular was backfilled into the cavity.

Torpedo emerges through growing medium and cell decks on the imaginary building side.

Torpedo set to begin at the imaginary building end of the lateral line.

Torpedo and hose are pulled up and out of the pit.

Afte r fa lse sta rt on i mag ina ry bui ldi ng e nd, t orp edo is re set a t ro ad end.

74


Pulling the lateral through the cells and growing medium.

E n d o f l a te r a l a t b u i l d i n g e n d .

C ove r ove r th e c e l l d e ck w i th t h e c u t g e o tex ti l e a n d a d d a n overlapping layer of geotextile on top.

R i s e r i s a t t a c h e d a n d p u l l e d t h ro u g h.

75

Ba c k f i l l a n d e n su r e r i se r i s s e t c o r r e c tl y.


Conclusions of the Enbridge Gas exercise

It was concluded that the soil cells pose no obstruction to the installation of a gas lateral and ris er. The work is essentially the same as cur rent sidewalk conditions with a few extra considerations. T he crew must locate the boundary of the cell frame to set the torpedo to g o between the cell deck legs and not collide into them. The crew must be mindful that the growing medium is ea sily permeable and that the torpedo bo res move easily from hard to soft mat ter and not the other way around. Paving removal need only be limited to where the riser needs to go and the area needed to slide it into place. Where there is enough room bet ween the soil cells and building face to excavate and install the riser, paving on top of the cells could stay intact.

76


7.3 Bloor Street West at Dovercourt Rd. and Concord Ave. Demonstration Project A demo d emo nst nstrat ration ion pro projec jectt was w as plan ned to test t est the typologies developed in this study under the sidewalk through a combined growing medium trench, structural pavement slab and soil cell condition along a shor t stretch of the north side of Bloor St. W. from Dovercourt Rd. to Concord Ave. It was decided by the City not to implement this demonstration exercise as part of the scope of this study. The City of Toronto is proposing a 3.5 km ro ad resurfacing projec t along Bloor St. W. for 2013. To avoid any schedule disruption to the larger resur facing project planned for Bloor St. W., the tree planting pilot project from Dovercour t Rd. to Concord Ave. will not be implemented.

Existing Enbridge temporary trench repair with unshrinkable fill and asphalt.

C o n c o r d

S t o o r B l o

. W.

D o v e r c o u r t R d .

77


A v e .

50 Park Road Toronto, Toront o, Ontari o M4W 2N5 T 416 968 9479 F 416 968 0687 www.dtah.com

Appendices Append ices

Tree Planting Solutions in Hard Boulevard Surfaces Best Practices Manual

Construction Drawings Ap pe pendi ndi x A Construction Ap pe pendi ndi x B Construction Specifications Ap pe pendi ndi x C Cost Comparison Ap pe pendi ndi x D Nashdene Yard Demonstration Project Ap pe pendi ndi x E Bloor-Dovercourt Demonstration Project

| ARUP | James Urban Urban - Urban Trees + Soils Soils | Urban Forest Innovations Inc.

Appendix A

Construction Drawings

50 Park Road Toronto, ON M4W 2N5 t: 416.968.9479

Suite 2400 - 2 Bloor St. W. Toronto, ON M4W 1A8 t: 416.515.0915

TREE PLANTING SOLUTIONS IN HARD BOULEVARD SURFACES

915 Creek Drive Annapolis, MD 21403 t: 410.263.4838

UFI

1248 Minnewaska Trail Mississauga, ON L5G 3S5 t: 905.274.1022

3

2013-02-08

Best Practices Manual-100% Submission-R1

2

2012-07-31

Best Practices Manual - 100% Submission

1

2012-02-29

Issued for City Review - 90% Submission

No .

DATE

REVISIONS

TYPE-1A: CAST-IN-PLACE STRUCTURAL CONCRETE PANELS OVER CONTINUOUS GROWING MEDIUM TRENCH

All dimensions are in millimetres unless otherwise noted.

LAYOUT & MATERIALS PLAN

T-1A.1

SCALE: NTS






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LAYOUT & MATERIALS PLAN WITH SOIL CELLS

SCALE: NTS


T-1A.2





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TYPICAL SECTIONS

T-1A.3

SCALE: AS SHOWN

LOCKING OF BICYCLES PROHIBITED BICYCLESWILL BEREMOVEDAT OWNER'SRISK






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TYPICAL SECTION THROUGH PANEL 'B' @ TREE OPENING

SCALE: 1:30


T-1A.4






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TYPICAL SECTIONS WITH SOIL CELLS

T-1A.5

SCALE: 1:30





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TYPE-1B: PRECAST STRUCTURAL CONCRETE PANELS & UNIT PAVING OVER CONTINUOUS GROWING MEDIUM TRENCH


LAYOUT & MATERIALS PLAN

T-1B.1

SCALE: NTS





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LAYOUT & MATERIALS PLAN WITH SOIL CELLS

T-1B.2

SCALE: NTS





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TYPICAL SECTIONS

T-1B.3

SCALE: AS SHOWN






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TYPICAL SECTION THROUGH PANEL 'B' @ TREE OPENING

T-1B.4

SCALE: 1:30






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T-1B.5

SCALE: 1:30


TYPE-2: SOIL CELLS IN CONTINUOUS GROWING MEDIUM TRENCH


LAYOUT & MATERIALS PLAN WHERE LATERAL LINES RUN UNDER SIDEWALK

T-2.1




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LAYOUT & MATERIALS PLAN WHERE MAIN LINES RUN UNDER SIDEWALK

T-2.2




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SCALE: NTS







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TYPICAL SECTIONS @ MIDBLOCK

SCALE: 1:30

T-2.3

BICYCLES PROHIBITED BICYCLESWILL BEREMOVEDAT OWNER'SRISK

BICYCLES PROHIBITED BICYCLESWILL BEREMOVEDAT OWNER'SRISK







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TYPICAL SECTIONS @ TREE OPENING

SCALE: 1:30

T-2.4


TYPE-3: OPEN PLANTER


LAYOUT & MATERIALS PLANS

T-3.1




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SCALE: 1:150




LAYOUT & MATERIALS PLANS WITH SOIL CELLS

T-3.2




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SCALE: 1:150




TYPICAL SECTIONS

T-3.3




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SCALE: 1:30





T-3.4




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TYPICAL COMPONENTS


RAINWATER DISTRIBUTION SYSTEM DETAILS

TC-1




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TYPICAL COMPONENTS


RAINWATER DISTRIBUTION SYSTEM DETAILS

TC-2




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TYPICAL COMPONENTS


METAL PAVER EDGE DETAILS

TC-3




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SCALE: AS SHOWN


TYPICAL COMPONENTS


ROOT ZONE ID & SOIL INSPECTION PORT DETAILS

TC-4




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TYPICAL COMPONENTS


CURB WITH DECORATIVE BAND OPTION DETAILS

TC-5




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STRUCTURAL DESIGN


TYPE-1A: CAST-IN-PLACE STRUCTURAL CONCRETE PANEL

S-1




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STRUCTURAL DESIGN


TYPE-1B: PRECAST STRUCTURAL CONCRETE PANEL

S-2




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STRUCTURAL DESIGN


LIMITATIONS FOR CORING/SLEEVING CORING/SLEEVING & NOTCHING/BOX-OUTS

S-3




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LOCKING OF BICYCLES PROHIBITED BICYCLES WILL BE REMOVED AT OWNER'S RISK

LOCKINGOF BICYCLES PROHIBITED BICYCLESWILL BEREMOVEDAT OWNER'SRISK

PLANTING DETAILS






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TREE PLANTING DETAIL

SCALE: NTS

PL-1


PLANTING DETAILS


GROWING MEDIUM DETAILS

PL-2




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Appendix Append ix B

Construction Specifications

Division 01 – General Requirements

To be prepared per individual project by Consultant (NOT INCLUDED)

Division 03 – Concrete

03 20 00

Concrete Reinforcing

03 45 00

Precast Architectural Concrete

Division 05 – Metals

05 50 00

Metal Fabrications

Division 32 – E xterior Improvements

32 84 10

Rain Water Distribution

32 88 88 32 91 21

Soil Cells Growing Medium

32 93 00

Planting

Ontario Provincial Standard Specifications (provided by Province of Ontario)

OPSS 51 510 0

Construction Specification for Removal

OPSS 909

Construction Specification for Prestressed Concrete – Precast Members

OPSS 919 OPSS 101 1010 0

Construction Specification for Formwork and Falsework Material Specification for Aggregates – Base, Subbase, Select Subgrade, Backfill

OPSS 1860

Material Specification for Geotextiles

City of Toronto Standard Construction Specif ications (provided by City of Toronto) Toronto)

TS 3.70

Construction Specification for Concrete Sidewalk and Concrete Raised Median

TS 3.80

Construction Specification for Concrete Unit Pavers

TS 101 1010 0

Amendments to OPSS 101 1010 0 (Apr 04) – Material Specification for Aggregates – Base, Subbase, Select Subgrade, and Backfill Material

TS 1860

Amendments to OPSS 1860 (Mar 98) – Material Specification for Geotextiles

CITY OF TORONTO TREE PLANTING SOLUTIONS IN HARD BOULEVARD SURFACES

Part 1

General

1.1

RELATED SECTIONS

.1 1.2

SECTION 03 20 00 CONCRETE REINFORCING PAGE 1 OF 3

TS 3.70 Construction Specification for Concrete Sidewalk and Concrete Raised Median MEASUREMENT PROCEDURES

.1

1.3

Measure reinforcing steel in tonnes of steel incorporated into Work, computed from theoretical unit mass specified in CAN/CSA-G30.18 for lengths and sizes of bars as indicated or authorized in writing by Engineer. REFERENCES

.1

American Concrete Institute (ACI) .1

.2

.4

ACI 315-99, Details and Detailing of Concrete Reinforcement.

.2

ACI 315R-04, Manual of Engineering and Placing Drawings for Reinforced Concrete Structures.

ASTM A775/A775M-04a, Standard Specification for Epoxy-Coated Reinforcing Steel Bars.

Canadian Standards Association (CSA International) .1

CSA-A23.1-[04]/A23.2-04, Concrete Materials and Methods of Concrete Construction/Methods of Test and Standard Practices for Concrete.

.2

CSA-A23.3-04, Design of Concrete Structures.

.3

CAN/CSA-G30.18-M92(R2002), Billet-Steel Bars for Concrete Reinforcement, A National Standard of Canada.

.4

CSA W186-M1990(R2002), Welding of Reinforcing Bars in Reinforced Concrete Construction.

Reinforcing Steel Institute of Canada (RSIC) .1

1.4

.1

American Society for Testing and Materials International (ASTM) .1

.3

SP-66-04, ACI Detailing Manual 2004.

RSIC-2004, Reinforcing Steel Manual of Standard Practice.

SUBMITTALS

.1

Prepare reinforcement drawings in accordance with RSIC Manual of Standard Practice and ACI 315.

.2

Submit shop drawings including placing of reinforcement and indicate: .1

Bar bending details.

.2

Lists.

.3

Quantities of reinforcement.

.4

Sizes, spacings, locations of reinforcement and mechanical splices if approved by Engineer, with identifying code marks to permit correct placement without reference to structural drawings.

.5

Indicate sizes, spacings and locations of chairs, spacers and hangers.


.3

1.5

PAGE 2 OF 3

Detail lap lengths and bar development lengths to CSA-A23.3, unless otherwise indicated. .1

.4

SECTION 03 20 00 CONCRETE REINFORCING

Provide type B tension lap splices at all splice locations indicated.

Quality Assurance: as described in PART 2 - SOURCE QUALITY CONTROL. .1

Mill Test Report: upon request, provide Engineer with certified copy of mill test report of reinforcing steel, minimum 4 weeks prior to beginning reinforcing work.

.2

Upon request submit in writing to Engineer proposed source of reinforcement material to be supplied.

DELIVERY, STORAGE AND HANDLING

.1

Waste Management and Disposal: .1

Place materials defined as hazardous or toxic in designated containers.

Part 2

Products

2.1

MATERIALS

.1

Substitute different size bars only if permitted in writing by Engineer.

.2

Reinforcing steel: billet steel, grade 400, deformed bars to CAN/CSA-G30.18, unless indicated otherwise.

.3

Reinforcing steel: weldable low alloy steel deformed bars to CAN/CSA-G30.18.

.4

Epoxy Coating of non-prestressed reinforcement: to ASTM A775/A775M.

.5

Chairs, bolsters, bar supports, spacers: to CSA-A23.1/A23.2.

.6

Mechanical splices: subject to approval of Engineer.

2.2

FABRICATION

.1

Fabricate reinforcing steel in accordance with CSA-A23.1/A23.2 and Reinforcing Steel Manual of Standard Practice by the Reinforcing Steel Institute of Canada.

.2

Obtain Engineer approval for locations of reinforcement splices other than those shown on placing drawings.

.3

Upon approval of Engineer, weld reinforcement in accordance with CSA W186.

.4

Ship bundles of bar reinforcement, clearly identified in accordance with bar bending details and lists. .1

2.3

Ship epoxy coated bars in accordance with ASTM A775A/A775M.

SOURCE QUALITY CONTROL

.1

Upon request, provide Engineer with certified copy of mill test report of reinforcing steel, showing physical and chemical analysis, minimum 4 weeks prior to beginning reinforcing work.

.2

Upon request, inform Engineer of proposed source of material to be supplied.

CITY OF TORONTO TREE PLANTING SOLUTIONS IN HARD BOULEVARD SURFACES Part 3

Execution

3.1

FIELD BENDING

SECTION 03 20 00 CONCRETE REINFORCING PAGE 3 OF 3

.1

Do not field bend or field weld reinforcement except where indicated or authorized by Engineer.

.2

When field bending is authorized, bend without heat, applying slow and steady pressure.

.3

Replace bars, which develop cracks or splits.

3.2

PLACING REINFORCEMENT

.1

Place reinforcing steel as indicated on placing drawings and in accordance with CSA-A23.1/A23.2.

.2

Prior to placing concrete, obtain Engineer approval of reinforcing material and placement.

.3

Ensure cover to reinforcement is maintained during concrete pour.

.4

Protect epoxy coated portions of bars with covering during transportation and handling.

3.3

FIELD TOUCH-UP

.1

Touch up damaged and cut ends of epoxy coated reinforcing steel with compatible finish to provide continuous coating.

END OF SECTION 03 20 00


SECTION 03 45 00 PRECAST ARCHITECTURAL CONCRETE - LANDSCAPE PAGE 1 OF 5

Part 1 General 1.1

SECTION INCLUDES

.1

1.2

SUBMITTALS

.1

Submit required submittals in accordance with Section 01 33 00.

.2

Shop Drawings: .1

Submit shop drawings.

.2

Include plans, sections and large scale details, and indicate components and methods of assembly, materials and their characteristics, fastenings, and their structural characteristics relative to their purpose, and other fabrication information required.

.3

Mock-ups: .1 Provide mock-up installations installatio ns as directed by the City and conforming to typical construction for work of this section. .2 Mock-ups shall show the proposed colours and finishes, and other pertinent details of installation.

.4

Closeout submittals: .1 Submit closeout submittals in accordance with Section 01 77 00.

1.3

EXAMINATION

.1

1.4

1.5

Labour, materials, tools, and equipment, required to supply and install precast concrete reglets.

Examine surfaces which are to receive the work of this Section and do not proceed until unsatisfactory conditions are corrected. Report defects of work prepared by other Sections which affect the work of this Section. Commencement of work shall imply acceptance of surfaces and tolerances.

QUALIFICATIONS

.1

Work shall be executed only by a company with proven experience in the design and manufacture of architectural precast concrete and having adequate finances, equipment, plant and skilled personnel to expeditiously detail, fabricate and install the work of this Section as required by the Drawings and Specification.

.2

Manufacturer shall be responsible for the design, connections and installation of the precast concrete units and shall direct the placing of items to be cast in the concrete work.

.3

Manufacturer shall be qualified in accordance with CSA A23.4-00/A251 Qualification Qualificat ion Code for Manufacturers of Architectural and Structural Precast Concrete.

DESIGN


.1

1.6

1.7

Part 2 2.1


Design of precast concrete members, connections and anchorages tied into the structure shall be carried out under the direction of a civil engineer experienced in the field and licensed to practice in the Province of Ontario, who shall seal each and every shop and erection drawing attesting to the adequacy of the members, their reinforcement and connections for the design and construction. This same design engineer shall provide both in-shop and on-site periodic review of the work during construction.

HANDLING, STORAGE AND PROTECTION

.1

Design and cast lifting devices into the units to ensure that they will be safely and efficiently handled at times. Lifting devices shall be so arranged that they do not have to be removed, or if they must be removed, they shall be arranged so that they are readily filled by this Section.

.2

Stack units on properly cushioned supports to protect the edges.

.3

Do not permit units to contact earth or other staining influences or to rest on corners.

.4

Protect stockpiles against inclement weather.

.5

Protect holes and reglets against water and ice in freezing weather.

.6

Protect the work of other Sections during erection and final cleaning.

.7

Protect work while in progress. Protect work at openings and exposed corners where there is likelihood of damage with substantial non-staining coverings and remove up on completion of work of this trade.

WARRANTY

.1

This Section shall produce precast units which will not spall or show evidence of visible cracking, rust, splitting, deformation, or loosening resulting from inferior materials or workmanship by this trade and upon completion of the work of this Subcontract, provide the City with a written labour and material warranty in which this Subcontractor shall undertake to correct faulty workmanship and to replace deteriorated or faulty materials which may develop or become apparent during warranty period, promptly upon notification by the City of such deterioration or faulty work.

.2

Provide standard warranty with a duration of two (2) years in accordance with General Conditions. Warranty shall be in writing and shall warrant work under this Section to be free from defects for the period stipulated.

Products MATERIALS

.1

Precast concrete units: .1 .2

White cement, water reducer, air entrainment, aggregates, water admixture: to CSA A23.4/A251 and CAN/CSA A23.1/A23.2. Aggregate: in conformance with CAN/CSA A23.1/A23.2, face mix aggregate as selected by the City, to match samples as provided by the City.


.3 .4

.5

.6 .7 .8

.9

2.2


Sand: silica or sandstone of approved source, as selected by the City. Admixture: in accordance with CAN/CSA A23.1-A23.2. Introduce admixtures to concrete at time of batching in accordance with the manufacturer’s recommendations. Under no circumstances, use calcium chloride on an admixture containing calcium chloride. Admixtures shall be subject to the approval of the City. Reinforcing steel as required: billet steel bars conforming to CAN/CSA-G30.18. Reinforcing larger than 6 mm dia. shall be deformed bars conforming to the same standard. Welded wire mesh shall conform to CSA G30.5. Galvanize reinforcing with less than 25 mm cover. Water: in accordance with CAN/CSA A23.1/A23.2. Structural steel: new material conforming to CSA G40.20, or ASTM Designation A36M. Concrete mix: .1 Use concrete mix designed to produce minimum of 35 MPa compressive strength at 28 days, with a maxiumum water/cement ration to CSA A23.4-00/A251. .2 Use same brand and source of cement and aggregate for facing, for entire project to ensure uniformity of colouration and other mix characteristics. .3 Cement colour in facing matrix to be determined by the City. .4 Air entrainment of concrete mix: to CAN/CSA A23.1/A23.2, 5% minimum. .5 Use of calcium chloride not permitted. Forms: constructed or approved concrete, steel or fiberglass reinforced plastic or high density overlaid plywood conforming to CSA O121 to obtain the quality of the finish specified.

FABRICATION

.1

Exposed faces of precast concrete members shall be made to requirements requirem ents of CSA A23.4/A251, A23.4/A251, Finish Grade Grade ‘A’.

.2

Precast concrete exposed surface finish shall match approved samples. Colour and texture shall be uniform and consistent throughout, free from air pockets, imperfections, blemishes and discolourations.

.3

Fabricate units to profiles and sizes detailed and in accordance with shop drawings and to requirements of local authority having jurisdiction over work.

.4

Execute work accurately, true to dimensions, square, in true planes, free from waves, twists, cracks, checks and broken edges. Warped, cracked, chipped or broken units shall not be placed in work. Edges shall be straight and with clean accurate arises.

.5

Quality of concrete, placing materials in forms, vibrating, curing, stripping and handling shall be in accordance with CSA A23.4-00/A251-00 and this Standard shall apply to precast concrete units required under this Section.

.6

Fabricate precast work within dimensional tolerances as specified in CSA A23.4-00/A251.

.7

Identify precast units with a number on back face as well as mark identifying orientation of unit in final position.

.8

Curing shall be in accordance with the requirements of CSA A251.



Part 3 Execution 3.1

DESIGN

.1

3.2

DIMENSIONS

.1

3.3

3.4

3.5

Design precast concrete work and connections in accordance with CSA A23.4/A251and requirements of authorities having jurisdiction.

Check dimensions at site before commencing shop drawings and before fabrication and report discrepancies to the City.

INSTALLATION

.1

Erect precast concrete units in accordance with CSA A23.4-00/A251-00 A23.4-00/A251-0 0 and this Standard shall apply to precast concrete units required under this section.

.2

Apply setting adhesive in accordance with manufacturer's manufacturer' s instructions.

.3

Set work plumb, true and square with joints parallel and uniform. Set elevations and alignment between units to within allowable tolerances before connecting units.

.4

Where tolerances will interfere interfer e with work of other sections that will force other work to be out of plumb, level, or deviate from straight lines indicated, provide remedial work for this defect.

.5

Install each precast concrete unit in a way to permit removal and replacement of a defective and condemned panel without damaging adjacent panels.

.6

Supply adequate information on handling and installation methods.

REJECTION OF WORK

.1

Any concrete units containing concrete which have failed to meet strength requirements of plans and specification shall be cored as directed by the City. Unit may be rejected and replaced at the City’s discretion after core test. Units fabricated out-of-square, out-ofdimension, without proper reinforcement, proper opening or inserts, shall be rejected and replaced at the City’s discretion. The costs of these tests shall be borne by this Section.

.2

Damaged, chipped, rust stained, and discoloured units shall be replaced, patched or refinished as directed by the City. The City will be the sole judge of the acceptance of any patched, repaired or refinished panels.

.3

Except for hair cracks which are defined as surface cracks of minute width, visible but not measurable by ordinary means, units which have become cracked or broken will be rejected and shall be replaced.

CLEAN-UP

.1

Remove, as work progresses, excess or foreign materials which would set up or become



difficult to remove from finished surfaces. .2

At completion, clean exposed surfaces of precast units. Remove dirt and other extraneous matter. Do not use acids without the City’s acceptance.

.3

Take precautions to prevent staining the material of others during cleaning operations.

END OF SECTION SECTION 03 45 00 00


Section 05 50 00 METAL FABRICATIONS Page 1

PART 1 - GENERAL 1.1

SECTION INCLUDES .1

1.2 .1 .2 .3 .4 .5 1.3

Work of this section includes metal fabrications and related metals including, but not limited to, the following: .1 Galvanized steel plate, 12 mm thick. RELATED SECTIONS Section 01 10 00 - General Instructions. Section 01 33 00 - Submittals. Section 32 14 14 – Precast Concrete Unit Pavers TS 3.70 – Construction Specification for Concrete Sidewalk and Concrete Raised Median OPSS 909 – Construction Specification for Prestressed Concrete – Precast Members

REFERENCES .1 The standards referenced in this section are to the following editions: .1 AAMA 611-98 Voluntary Specification for Anodized Architectural Aluminum. .2 ANSI H35.1-06 – American National Standard Alloy and Temper Designation Systems for Aluminum (U.S. & Metric Units). .3 ASTM A167-99(2004) – Standard Specification for Stainless and Heat-Resisting Chromium-Nickel Steel Plate, and Strip. .4 ASTM A269-04 – Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service. .5 ASTM A276-06 – Standard Specification for Stainless Steel Bars and Shapes. .6 ASTM A307-04 – Standard Specification for Carbon Steel Bolts and Studs, 60 000 PSI Tensile Strength. .7 ASTM B32-94 – Standard Specification for Solder Metal. .8 ASTM B663-96(2006) – Standard Specification for Silver-Tungsten Carbide Electrical Contact Material. .9 CAN/CSA G164-M81 – Hot Dip Galvanizing of Irregularly Shaped Articles. .10 CAN/CSA-S16.1-94 - Limit States Design of Steel Structures. .11 CSA W47.1-03 – Certification of Companies for Fusion Welding of Steel. .12 CSA W47.2-M1987(R2003) W47.2-M1987(R2003)– – Certification of Companies for Fusion Welding of Aluminum. .13 CSA W55.3-1965 – Resistance Welding Qualification Code for Fabricators of Structural Members Used in Buildings. .14 CSA W59-03 – Welded Steel Construction (Metal Arc Welding). .15 CSA W59.2-M1991(R2003) – Welded Aluminum Construction.

1.4

QUALITY ASSURANCE .1

.2

General: the work of this section shall be executed only by a Subcontractor who has adequate plant, equipment, and skilled tradespersons to perform work expeditiously, and is known to have been responsible for satisfactory installations similar to that required in the Work during a period of at least the immediate past 5 years. Welding: .1 Weld structural components in steel to conform to requirements of CSA W59, and by a fabricator fully certified by the Canadian Welding Bureau to conditions


.2

.3


of CSA W47.1 and W55.3 as applicable. Weld components in aluminum to conform to requirements of CSA 59.2, and by a fabricator certified by the Canadian Welding Bureau to conditions of CAN/CSA W47.2. Requirements of regulatory agencies: the work of this section that functions to

resist forces imposed by dead and live loads shall conform to requirements of jurisdictional authorities. .4 Conduct a pre-installation meeting in accordance with Section 01 31 19. 1.5

SUBMITTALS .1 .2

.3

.4

1.6

Submit required submittals in accordance with Section 01 33 00. Product data sheets: .1 Submit manufacturer’s Product data sheets for Products proposed for use in the work of this section. .2 Submit WHMIS data sheets for applied finish coatings. Shop Drawings: .1 Submit engineered shop drawings in accordance with Section 01 33 00. .2 Submit shop drawings in accordance with Section 01 33 00. .3 Include plans, sections and large scale details, and shall indicate components and methods of assembly, materials and their characteristics, fastenings, metal finishes, welds, and their structural characteristics relative to their purpose, and other fabrication information required. .4 Indicate proposed site connections and methods. .5 Indicate metal finishes. .6 Indicate grain direction for stainless steel work. Mock-ups .1 Provide mock-ups for the following items: .1 Galvanized Steel paver edge.

DESIGN REQUIREMENTS .1 .2

Design, fabricate, and install in accordance with the building code and requirements of all other governing authorities. Design assemblies and connections to withstand own dead load, super-imposed dead loads, and fabrication forces, without permanent distortions or deformation, to maximum allowable deflection of L/360, within the following construction tolerances: .1 Maximum variation from plumb in vertical lines: .1 3.2 mm (1/8”) in 3 m (10 ft) .2 Maximum variation from level: .1 3.2 mm (1/8”) in 9 m (30 ft.). .3 Maximum variation from straight: .1 3.2 mm (1/8”) in 3 m (10 ft.) under a 3 m (10 ft.) straight edge. .4 Maximum variation from angle indicated: .1 10 seconds. .5 Tolerances shall be non-cumulative.



1.7

WASTE MANAGEMENT AND DISPOSAL .1 Separate and recycle waste materials in accordance with Section 01 47 15. .2 Remove from site and dispose of packaging materials at appropriate recycling facilities. .3 Divert unused metal materials from landfill to metal recycling facility.

1.8

DELIVERY, STORAGE AND HANDLING .1 Label, tag or otherwise mark metal fabrications supplied for installation by other sections to indicate its function, location in building and shop drawing designation. .2 Protect work from damage during delivery, storage and handling. .1 Cover exposed stainless steel surfaces with pressure sensitive heavy protection paper or apply strippable plastic coating, before shipping to job site. .2 Leave protective covering in place until final cleaning of building. Provide instructions for removal of protective covering. .3 Deliver work to location at the Place of the Work designated by Contractor and to meet requirements of construction schedule.

PART 2 - PRODUCTS 2.1

MATERIALS .1

.2

General: .1 Unless detailed or specified otherwise, standard Products will be acceptable if construction details and installation meet intent of the Contract Documents. .2 Include materials, products, accessories, and supplementary parts necessary to complete assembly and installation of work of this section. .3 Incorporate only metals that are free from defects that are visible, or that impair strength or durability. Install only new metals of best quality, and free from rust or waves and buckles, and that are clean, straight, and with sharply defined profiles. Metals: .1 Steel materials: .1 Steel, structural shapes, plate, bars: hot-rolled, to meet specified requirements of CAN/CSA-G40.21, Grade 300W. .2 Steel, hollow structural sections: hot-formed, seamless, to meet specified requirements of CAN/CSA-G40.21, Grade 350W, Class H. .3 Steel, sheet: cold rolled, stretcher levelled, fully pickled, to meet specified requirements of ASTM A366 or SAE Specification 1010. .4 Steel Pipe: ASTM A53, Type E or S, Grade A or B, standard weight, Schedule 40 seamless black or AISI MT 1010/1015, or acceptable alternative. .2 Stainless steel materials: .1 Stainless steel tubing: to ASTM A269, Type 316, Type 316L at welded fabrications, Commercial Grade, seamless welded. .2 Stainless steel sheet and plate: ASTM A167, Type 316, Type 316L at welded fabrications. .3 Stainless steel sheet: AISI Type 316, Type 316L at welded fabrications). .4 Stainless steel bar and angle: ASTM A276, Type 316, Type 316L at welded fabrications. .3 Aluminum materials: .1 Aluminum extrusions: ASTM B211, Alloy 6063-T5, 6063-T6 or 6061-T6. .2 Aluminum sheet: ASTM B209, Alloy 1100, 3003 or 5005. For anodized finish is required use Alloy 5005.

CITY OF TORONTO TREE PLANTING SOLUTIONS IN HARD BOULEVARD SURFACES .3

2.1 .1

.2

.3


Finishes: .1 Galvanizing; hot dip after fabrication metal work: for irregular sections, zinc coating to meet specified requirements of CAN/CSA-G164. Use air cooling method (no water or chromate dipping treatment permitted). .2 Stainless steel: .1 Typical: AISI No. 4 brushed finish, grain direction as indicated on drawings. Where grain direction is not indicated, verify with Consultant prior to fabrication. .2 Heavy sandblasted finish: Submit samples showing a range of sandblasting coarseness for approval/selection by Consultant. .3 Aluminum: .1 Unexposed and exposed: Clear anodized to AAMA 611, designation AA-M10C22A41. .4 Fastenings: .1 ASTM A307, Type 304 stainless steel. .5 Welding materials: .1 Steel: to CAN/CSA W59. .2 Aluminum: to CAN/CSA W59.2. .6 Grout: .1 Epoxy grout: non-shrink, non-expanding, 'Sikadur Injection Gel Fast-Set' as manufactured by Sika Canada Inc., HY-150 as manufactured by Hilti, REZIWELD 3/2 EPOXY GROUT/PATCH by W.R. Meadows, or approved alternative.

FABRICATION General: .1 Fabricate metal fabrications with machinery and tools specifically designed for the intended manufacturing processes and by skilled tradesmen. .2 Fit and assemble metal fabrications in shop. When this is not possible, make a trial shop assembly. .3 Do welding work in accordance with CSA W59 and CSA W59.2, as applicable, unless specified otherwise. Construction: .1 Fabricate with materials, component sizes, metal gauges, reinforcing, anchors, and fasteners of adequate strength to withstand intended use, and within allowable design factors imposed by jurisdictional authorities. Fabricate items from steel unless otherwise noted. .2 Ensure that metal fabrications will remain free of warping, buckling, opening of joints and seams, distortion, and permanent deformation. .3 Provide drainage holes at exterior exposed tubular fabrications to permit drainage of trapped moisture. Assembly: .1 Accurately cut, machine and fit joints, corners, copes and mitres so that junctions between components fit together tightly and in true planes. .2 Fasten work with concealed methods unless otherwise indicated. .3 Weld connections where possible, bolt where not possible, and cut off bolts flush with nuts. Countersink bolt heads, and incorporate method to prevent loosening of nuts. Ream holes drilled for fastenings. .4 Provide continuous welds, where exposed to view unless otherwise indicated. Weld and grind welds to provide flat flush and finish to match adjacent finish,


.4

.5


where exposed to view. .5 Allow for differential movements within assemblies and at junctions of assemblies with surrounding Work. Finish work: .1 Incorporate holes and connections for work installed under other sections. .2 Cleanly and smoothly finish exposed edges of materials including holes. .3 Cap open ends of sections exposed to view, such as pipes, channels, angles, and other similar work. .4 For welded stainless steel fabrications continuous weld, grind welds smooth and flat where exposed to view and polish to match metal finish. Galvanizing: .1 Galvanize metal fabrications following fabrication.

PART 3 - EXECUTION 3.1 .1 .2 .3

3.2

INSTALLATION Install metal fabrications plumb, true, square, straight, level, and accurately and tightly fitted together and fit to surrounding work. Make field connections with bolts or weld as indicated to CAN/CSA-S16.1. Attach metal fabrications with mechanical fasteners to support load with minimum safety factor of 3. ADJUSTMENT AND CLEANING

.1 .2

3.3 .1 .2

After erection, touch up finished surfaces that are burned, scratched or otherwise damaged. Remove damaged, dented, defaced, defectively finished, or tool marked components and replace with new.

PROTECTION Maintain protection of work of this section from time of installation until final finishes are applied or to final cleanup. Protect finished surfaces from damage.


CITY OF TORONTO TREE PLANTING SOLUTIONS

SECTION 32 84 10 RAINWATER DISTRIBUTION SYSTEM

IN HARD BOULEVARD SURFACES

PAGE 1 OF 4


1.2

1.3

1.4

WORK INCLUDES

.1

The work consists of installing precast concrete reglets, catch basin, cast iron drain cover, inlets and pipes for a passive watering system to irrigate tree roots.

.2

The construction of the watering system will include furnishing, installing and testing of all irrigation equipment, along with the restoration of the site to its original condition.

RELATED WORK

.1

Section 03 45 00.02 Precast Architectural Concrete - Landscape

.2

Section 05 50 00 Metal Fabrications

.3

Section 32 91 21 Growing Medium

.4

Section 32 93 00 Planting

MATERIALS AND WORKMANSHIP

.1

Engage an experienced installed with minimum five (5) years’ experience with work similar in material, design and extent to that indicated for this Project.

.2

All materials will be new and without flaws or defects.

.3

All materials will be guaranteed for a period of one (1) year against material defects and workmanship.

SUBMITTALS

.1

1.5

1.6

Prior to construction, submit samples, product data and descriptive literature for all materials that will be used on the project. Submittals must be approved by the City before construction begins.

MOCK-UP OF SYSTEM

.1

The installer shall prepare an operational mock-up of the rain water distribution system that shall be completed in two stages. The mock-up must be completed and reviewed by the City before construction can begin.

.2

Stage 1 shall consist of one rain water distribution closed loop. The loop shall be installed as specified. The piping network shall be visible for inspection by the City. The contractor shall demonstrate the operation of the system by filling the rain water distribution system with water to the point where water flows out the upper holes.

.3

Stage 2 will consist of one finished rain water distribution closed loop that is connected to the drain inlet and catch basin and covered by soil and the finished surface.

AS-BUILT DRAWINGS




1.7

PAGE 2 OF 4

.1

Upon completion and approval of work by the City, prepare an as-built drawing of the system indicating the pipe size and location and dimensioned location of buried sleeves and pipes.

.2

The as-built drawing will be drawn to scale.

UTILITIES

.1

The Installing Contractor shall be aware of all public utilities servicing the property, and provide written notation pertaining to all private utilities located on the property.

.2

The Contractor shall notify the utility companies and arrange for cable locations prior to the commencement of any work, and shall be responsible for any damage to the public and private utilities described above.


2.2

PIPE

.1

Identification: All pipe will be continuously and permanently marked with the manufacturer’s name or trademark, size, schedule and type of pipe, and working pressure at 21 degrees Celsius.

.2

Delivery: Plastic pipe will be delivered to the site and stored in such a manner to provide adequate protection for the pipe ends either threaded or plain.

.3

P.V.C. Pipe and Fittings: All P.V.C. pipe will be class 160 (SDR-26) Ø100mm direct burial pipe and will be homogeneous throughout and free from visible cracks, dents, holes or foreign materials. All plastic pipe fittings to be installed shall be a minimum of schedule 40 molded fittings manufactured of the same material as the pipe and shall be suitable for solvent weld, slip joint ring tight seal. For bends, fittings shall be long sweep elbows. Tee fittings shall be sanitary tees.

.4

Approved suppliers: Martek Corp Inc.; Greenleaf Products. Alternates must be approved by the City.

.5

After installation, on upper side of pipe, drill ninety (90) Ø6.35mm (gauge E) holes along length of pipe loop. Evenly space the holes.

GEOTEXTILE

.1 2.3

2.4

Geotextile per OPSS 1860 / City of Toronto Specification TS 1860.

CATCH BASIN

.1

Approved product: F-900 IN-LINE CATCH BASIN, manufactured by ACO. Catch basin to include F900 black powdercoated catch basin frame and Series 900 plastic trash bucket. Alternates must be approved by the City. Ci ty.

.2

Perforate the catch basin to connect the outlet pipe, per manufacturer’s specification.

DRAIN COVER




.1

2.5

Custom cast iron drain cover, or approved equal: per detail drawings. Submit shop drawings indicating tamper-proof fasteners to be used. Ensure that cover fits into catch basin frame.

WATERING/AERATION WATERING/AERATION INLET

.1

2.6

PAGE 3 OF 4

Approved supplier: 100mm inlet by Martek Corp Inc., or Greenleaf Products. Alternates must be approved by the City.

PRECAST CONCRETE REGLET

.1

Custom precast concrete reglet per detail drawings and specification. Submit shop drawings.

PART 3 - EXECUTION

3.1

.1

Plastic pipes will be installed in a manner to provide for expansion and contraction as recommended by the manufacturer.

.2

All plastic to plastic joints will be solvent-weld joints or slip seal joints. Only the solvent recommended by the pipe manufacturer shall be used. All plastic pipe and and fittings will be installed as outlined and instructed by the pipe manufacturers.

.3

Pipe layout to be per drawings.

.4

The 100mm perforated pipe shall be installed so that it is level and on the surface of the final finished grade of growing medium.

.5

Ensure that holes in pipe are on top side of pipe and not the bottom.

.6

The bottom of the 100mm perforated pipe shall be no more than 50mm higher than the bottom elevation of the 100mm PVC header pipe. The tolerance for this dimension shall be 50mm +0mm/-6mm.

.7

Place geotextile on top of the perforated pipe.

CATCH BASIN

.1

3.2

DRAIN COVER

.1 3.3

Fasten drain cover with tamper-proof fasteners onto concrete shoulders/base per drawings.

WATERING/AERATION INLET

.1

3.4

Install catch basin and components per layout plans and details. Catch basin to be cast into concrete, per drawings and manufacturer’s specification.

Install watering/aeration inlet per layout plans and manufacturer’s specification. Connect to perforated PVC pipe.

PRECAST CONCRETE REGLET

.1

Install precast concrete reglet where shown in layout plans. Set into high performance mortar and ensure top of reglet is flush with adjacent finished grade.

CITY OF TORONTO

SECTION 32 84 10

TREE PLANTING SOLUTIONS

RAINWATER DISTRIBUTION SYSTEM


PAGE 4 OF 4

PART 4 - TESTING AND INSPECTION 4.1

4.2

TESTING

.1

Flush all lines and ensure that all silt is expelled from the system.

.2

Inspect all visible piping, and walk all buried lines for any leakage.

.3

Any repairs necessary to render the system in good working order will be completed prior to covering with soil or paving.

INSPECTION

.1

The system will not be considered complete and in compliance with the intent of these specifications and design until inspected by the Owner’s Representative.



SECTION 32 88 88 SOIL CELLS PAGE 1 OF 12

Part 1- General 1.1

RELATED DOCUMENTS .1

1.2

1.3

Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section.

RELATED SECTIONS .1 Section 32 91 21 Growing Medium .2

Section 32 93 00 Tree Planting

.3

Section 32 84 10 Rainwater Distribution System

.4

OPSS 1010 Material Specification for Aggregates – Base, Subbase, Select Subgrade, Backfill

.5

OPSS 1860 Material Specification for Geotextiles

.6

TS 1010 Amendments to OPSS 1010

.7

TS 1860 Amendments to OPSS 1860

SUMMARY .1 Contractors must provide trees with the specified net soil volume within a structured rooting space provided by the soil cell system. .2

Section Includes: .1

1.4

Furnishing and installing soil cell system, geotextile, geogrids, sub base material, backfill, drainage system, root barrier, and mulch, and the installation of Growing Medium.

DEFINITIONS .1 Aggregate Sub Base (below soil cells): Aggregate material between the bottom of the soil cell frame and the compacted subgrade below, designed to distribute loads from the frame to the subgrade. .2

Aggregate Base Course (above cell deck): Aggregate material between the paving and the top of the soil cell deck below designed to distribute loads across the top of the deck.

.3

Backfill: The earth used to replace or the act of replacing earth in an excavation beside the soil cell to the excavation extents.

.4

Finish Grade: Elevation of finished surface of Growing Medium or paving.

.5

Geogrid: Net-shaped synthetic polymer-coated fibers that provide a stabilizing force within soil structure as the fill interlocks with the grid and as defined in Part 2 – Products.

.6

Geotextile: A geosynthetic fabric, applied to either the soil surface or between materials, providing filtration, separation, or stabilization properties.

.7

Growing Medium: Soil as defined in Section "Growing Medium" intended to fill the soil cell system and other planting spaces.

.8

Root Barrier: Plastic root diversion device.

.9

Root package: The earthen package containing the root system of the tree as shipped from the nursery.


1.5


.10

Soil Cells: Structural system designed to be filled with Growing Medium for tree rooting and support of vehicle loaded pavements.

.11

Subgrade: Surface or elevation of subsoil remaining after completing excavation, or top surface of a fill or backfill.

.12

Subsoil: All soil beneath the topsoil layer of the soil profile, and typified by the lack of organic matter and soil organisms.

SUBMITTALS .1 Environmental Requirements and Procedures .1

Comply with all requirements and procedures in Section 01 35 43 Environmental Requirements and Procedures. .1

Submit materials water management plan that describes how materials will be managed at the site to prevent erosion and siltation from stored materials in accordance with Section 01 35 43 Environmental Requirements and Procedures paragraph Water Management, and General Construction Materials (Non Hazardous Materials)

.2

Submit testing data, waste material disposal plan for disposal of all excavated soil and fill material in accordance with Section 01 35 43 Environmental Requirements and Procedures, paragraph Waste Management.

.3

Submit letters and certificates of approval certifying that all fill material, including all aggregates and backfills meet the requirements of Sections 01 35 43 Environmental Requirements and Pr ocedures, paragraph General Construction Materials (Non Hazardous Materials) and Fill Materials.

.4

Submit letters of compliance that all contractors and subcontractors are in compliance with the provisions of Section 01 35 43 Environmental Requirements and Procedures, paragraph Environmental Management Plan, and Environmental Awareness Training.

.2

Upon seven (7) days prior to start of installation of items in this section, the Contractor shall provide submittals required in this section to the City for review and approval.

.3

Shop Drawings: Provide drawings signed and sealed by a professional engineer licensed to practice in the Province of Ontario.

.4

Product Data: For each type of product, submit manufacturer's product literature with technical data sufficient to demonstrate that the product meets these specifications.

.5

Samples for Verification: For each product where noted in the specification, submit samples as described.

.6

Compaction testing results: Submit results of all compaction testing required by the specifications including the bulk density test of the mock up and installed soil, and the compaction testing log of penetrometer and moisture meter readings to the City for approval.

.7

Qualification Data: Submit documentation of the qualifications of the soil cell installer sufficient to demonstrate that the installer meets the requirements of paragraph "Quality Assurance".

.8

Product Certificates: For each type of manufactured product, from manufacturer, and complying with the following:


1.6

1.7


.1

Manufacturer's certified analysis for standard products.

.2

Soil cell manufacturer's letter of review and approval of the project, plans, details and specifications for compliance with product installation requirements.

SEQUENCING AND SCHEDULING .1 General: Prior to the start of Work, Work , prepare a detailed schedule of the work for coordination with other trades. .2

Schedule all utility installations prior to beginning work in this section.

.3

Where possible, schedule the installation of soil cells after the area is no longer required for use by other trades and work. Protect installed soil cells from damage in the event that work must occur over or adjacent to the completed soil cells.

QUALITY ASSURANCE .1 Installer Qualifications: Soil cells and related products shall be installed by a qualified installer whose work has resulted in successful installation of Growing Mediums and planter drainage systems, underground piping, chambers and vault structures. .1

Submit list of completed projects of similar scope and scale to the City, demonstrating capabilities and experience.

.2

The installer and the field supervisor shall have a minimum of five years successful experience with construction of similar scope in dense urban areas.

.3

Installer's Field Supervision: Installer is required to maintain an experienced fulltime supervisor on Project site when work is in progress. progress. This person shall be identified during the Pre-installation Conference, with appropriate contact information provided, as necessary. The same supervisor shall be utilized throughout the Project, unless a substitution is submitted to and approved in writing by the City.

.4

.2

.3

.4

Installer will be required to take part in a half-day training session provided by the manufacturer. Training session to be attended by all foremen and key personnel involved in installation. Manufacturer will provide additional training during during mockup installation Provide mock up of soil installation and compaction evaluation:

.1

Prior to the installation of soil cells, construct a mock up of the complete installation at the site. The installation of the mock up shall be in the presence of the City.

.2

The mock up shall be a minimum of 10 square meters and include the complete soil cell system installation with sub base com paction, drainage installation, base course aggregate and geotextile as required, geogrids, backfill, Growing Medium with compaction, and top geotextile.

.3

The mock up area may remain as part of the installed work at the end of the Project provided that it remains in good condition and meets requirements of the Contract Documents.

Product Certificates: For each type of manufactured product, from manufacturer, and complying with the following: .1

Manufacturer's certified analysis for standard products.

.2

Soil cell manufacturer's letter of review and approval of the project, plans, details and specifications for compliance with product installation requirements.

Quality control required.


.5


.1

The contractor shall, engage the soil cell manufacturer to provide shop drawings, stamped by a Ontario licensed professional engineer, and t o provide periodic construction review by a Ontario licensed professional engineer, in order to ensure that the soil cells are constructed in accordance with the construction documents.

.2

The soil cell Ontario Professional Engineer responsible for the periodic review of the installation shall attend the pre-installation meeting.

Conduct a pre-installation meeting.

1.8

LAYOUT AND ELEVATION CONTROL .1 Provide layout and elevation control during installation of soil cells. Utilize grade stakes, benchmarks, surveying equipment and other m eans and methods to assure that layout and elevations conform to t he layout and elevations indicated on the plans.

1.9

PERMITS AND CODE COMPLIANCE .1 Comply with applicable requirements of the laws, codes, ordinances and regulations of Federal, Provincial and Municipal Municipal authorities having jurisdiction. Obtain necessary permits/approvals from all such authorities.

1.10

DELIVERY, STORAGE, AND HANDLING .1 Packaged Materials: Deliver packaged materials in original, unopened containers showing weight, certified analysis, analysis, name and address of manufacturer. Protect materials from deterioration during delivery and while on the project site. .2

1.11

Bulk Materials: Do not deliver or place backfill, soils and soil amendments in frozen, wet, or muddy conditions. .1

Do not dump or store bulk materials near structures, utilities, sidewalks, pavements, and other facilities, or on existing trees, turf areas or plants.

.2

Provide protection including tarps, plastic and or matting between all bulk materials and any finished surfaces sufficient to protect the finish material.

.3

Provide erosion-control measures to prevent erosion or displacement of bulk materials and discharge of soil-bearing water runoff or airborne dust to adjacent properties, water conveyance systems, systems, and walkways. Provide additional sediment control to retain excavated material, backfill, soil amendments and planting mix within the project limits as needed.

.4

Soil cells: Protect soil cells from damage during delivery, storage and handling. .1

Store under tarp to protect from sunlight when time from delivery to installation exceeds one week. week. Storage should occur on smooth surfaces, free from dirt, mud and debris.

.2

Handling is to be performed with equipment appropriate to the size (height) of Cells and site conditions, and may include, hand, handcart, forklifts, extension lifts, small cranes, etc., with care given to minimize damage to soil cells. Backhoes, front-end loaders and skid steers are considered inappropriate for soil cell transport and placement.

PROJECT CONDITIONS .1 Verification of Existing Conditions and Protection of New or Existing Improvements: Before proceeding with work in this section, the Installer shall caref ully check and verify all



dimensions, quantities, and grade elevations, and inform the City immediately of any discrepancies. .1

Carefully examine the civil, record, and survey drawings to become familiar with the existing underground conditions conditions before digging. Verify the location of all aboveground and underground utility lines, infrastructure, other improvements, and existing trees, shrubs, and plants to remain including their root system, and take proper precautions as necessary to avoid damage to such improvements and plants.

.2

In the event of conflict between existing and new improvements notify the City in writing and obtain written confirmation of any changes to the work prior to proceeding. .1

When new or previously existing utility lines are encountered during the course of excavation, notify the City in writing and m ake recommendations as to remedial action. Proceed with work work in that area only upon approval of appropriate remedial action. Coordinate all work with the appropriate utility contractors, utility company or responsible public works agency.

.2

Weather Limitations: Do not proceed with work when subgrades, soils and Growing Mediums are in a wet, muddy or frozen condition.

.3

Where construction sequencing requires work during cold weather, protect sub grades and bulk materials from freezing using covers or as needed heated tenting. Sub grades that are suffic iently well drained to preclude the buildup of ice m ay be installed and built upon during freezing weather provided the surface is cleared of snow and any ice bound material.

.4

Protect partially completed soil cell installation against damage from other construction traffic when work is in progress, and f ollowing completion with highly visible construction tape, fencing, or other means until construction is complete. Prevent all non-installation related construction traff ic over the completed soil cell installation; only allowing loads less than the design loads.

1.12

PROTECTION .1 Protect open excavations and partially completed Soil Cell installation from access and damage when work is in pr ogress, and following completion with highly visible construction tape, fencing, or other means until all construction is complete.

1.13

WARRANTY .1 Soil cell manufacturer's product warranty shall apply. Submit manufacturer's product warranty. .2

Warranty Warr anty for other products and installation of soil cells in this section shall be as described in Division 1.

1.14

PROJECT WORK .1 Coordinate installation with all other work that may impact the completion of the work.

1.15

PRECONSTRUCTION MEETING .1 Prior to the start of the installation of soil cells, meet at the site with the City, general contractor and the soil cells installer to review installation layout, procedures, means and methods.



Part 2 - Products 2.1

2.2

SOIL CELLS .1 Structural system designed to be filled with Growing Medium for tree rooting and support of vehicle loaded pavements meeting the following requirements: The structure shall be designed to support loads up to and including AASHTO H20 and Relevant Ontario Building Code standards for sidewalks.

.2

The structures shall be designed to be filled with the growing medium as specified in section 32 91 21 “ Growing Medium” including the type of soil specified; the required limitations of delivery, storage, and handling; the requirement to retain soil peds; and requirements to compact and in-situ test soil compaction to the ranges specified.

.3

The soil cells shall have been specifically designed and tested for the purpose of growing tree roots, and rainwater filtering, detention and retention.

.4

Critical to the soil cell design is that each soil cell or stack of soil cells shall be structurally independent of all adjacent soil cell stacks such that a single stack or group of stacks can be removed after the completion of installation to facilitate future utility installation and repair.

.5

The structural design of each Soil Cell unit shall facilitate the movement of roots and water between each cell and between the edges of the cell system and the surrounding soils. The design shall facilitate the installation, compaction and insitu soil compaction testing; installation and maintenance of utilities within and under the soil cells; the movement and expansion of roots; and the lateral capillary movement of water.

INSPECTION RISER AND CAP .1 Inspection riser shall consist of a rigid, schedule 40 non-perforated 100mm +/- diameter PVC pipe. .2

2.3

.1

Cap shall be cast iron clean out caps with screw top and inset lug designed to fit standard PVC schedule 40 pipe-fittings.

GEOGRID .1 Geogrid shall be high strength, high tenacity, high molecular weight polyester with the following properties: Ultimate Wide Width Tensile Strength

29.2 kN/m

Creep Reduced Strength

18.5 kN/m

Long Term Design Strength

16.0 kN/m

2.4

GEOTEXTILE .1 Refer to Class II non-woven geotextile per OPSS 1860.

2.5

AGGREGATE SUB BASE (BELOW CELL FRAME): .1 19mm crusher run limestone per TS 1010.

2.6

AGGREGATE BASE COURSE (ABOVE CELL DECK): .1 19mm crusher run limestone per TS 1010.



2.7

BACKFILL MATERIAL (ADJACENT TO SOIL CELLS): .1 Refer to OPSS 1010. Clean, compactable, coarse grained fill soil meeting the requirements of the Unified Soil Classification system for soil type GW, GP, GC with less than 30% fines, SW, and SC with less than 30% 30% fines. Backfill material shall be free of organic material, trash and other debris, and shall be free of toxic material injurious to plant growth.

2.8

GROWING MEDIUM - (See Specification Section - Growing Medium)

2.9

ROOT BARRIER .1 Root barrier shall prevent root penetration. The material shall be impermeable and ribbed with a thickness of 1mm to 2mm. The root barrier shall be the full depth of the soil cells.

Part 3 - Execution 3.1

LAYOUT APPROVAL APPROVAL .1 Prior to the start of work, layout and stake the limits of excavation and horizontal and vertical control points sufficient to install the soil cells and required drainage features in the correct locations.

3.2

UTILITY COORDINATION .1 Confirm that the layout of the soil cells is not in conflict with any existing or proposed utility lines or structures. In event that there is a conflict conflict notify the City and and take remedial actions to resolve the conflict as instructed by the City. Where needed, and approved by the City utility lines may be installed through the spaces within the soil cell frames.

3.3

Secure and brace all utility lines placed within the frames.

.2

Where lines require that the space between cells is larger than 75mm, use the manufacturer’s recommended spanning techniques to bridge paving over the gaps between frames.

EXCAVATION .1 Excavate to the depths and shapes indicated on the drawings. Base of excavation shall be smooth soil, level and free of lumps or debris. .2

3.4

.1

Excavate per manufacturer’s instructions.

SUB GRADE COMPACTION .1 Check compaction of the subgrade below the soil cells and confirm that the subgrade soil is compacted to a minimum of 95% of maximum dry density at optimum moisture content in accordance with ASTM D 698 Standard Proctor Method. .1

.2 3.5

Proof compact the subgrade with a minimum of three passes of a suitable vibrating compacting machine or apply other compaction forces as needed to achieve the required subgrade compaction rate.

Apply additional compaction forces at optimum water levels.

INSTALLATION OF GEOTEXTILE OVER SUBGRADE .1 Where indicated on the drawings by the project engineer, install geotextile over the compacted subgrade material.



Install the geotextile with a minimum joint overlap of 450 mm between sections of material.

3.6

INSTALLATION OF SOLID AND PERFORATED DRAIN LINES .1 Lay out the location of all drain lines. Adjust the alignments to conform to the final locations of sleeves and risers. Do not locate drain lines within 150mm of the edge of any soil cell edge.

3.7

INSTALLATION OF AGGREGATE SUB BASE BELOW SOIL CELL FRAME .1 Install aggregate sub base to the depths indicated on the drawings, under the first layer of soil cell frames. .2

Compact aggregate sub base layer to a minimum of 95% of maximum dry density at optimum moisture content in accordance with ASTM D 698 Standard Proctor Method. .1

.3

3.8

Compact the subgrade with a minimum of three passes of a suitable vibrating compacting machine or apply other com paction forces as needed to achieve the required subgrade compaction rate.

Grade surface in a plane parallel to the grades of the paving above. .1

The tolerance for dips and bumps in the aggregate under soil cells shall be a 9 mm deviation from the plane in 3000mm and 3 mm in 1200 mm.

.2

The grade and elevations of the base under the soil cells shall be approved by the City prior to proceeding with the installation of the soil cells.

INSTALLATION OF SOIL CELLS, GROWING MEDIUM, GEOGRID, AND BACKFILL .1 Refer to manufacturer’s instructions. .2

Identify the outline layout of the structure and the edges of paving around tree planting areas on the floor of the excavation, using spray paint or chalk line. T he layout shall be calculated to include shift in layout locations due to depth and the slope of the cells.

.3

Lay out the first layer of soil cell frames on the sub base. Verify that the layout is consistent with the required locations and dim ensions of paving edges to be constructed over the soil cells. .1

Check each soil cell frame unit for damage prior to placing in the excavation. Any cracked or chipped unit shall be rejected.

.4

Place frames no less than 25 mm and no more than 75 mm apart.

.5

Assure that each soil cell sits solidly on the surface of the sub base. Soil cells shall not rock or bend over any stone or other obstruction protruding above the surface of the sub base material. Soil cells shall not bend into dips in the sub base material. The maximum tolerance for deviations in the plane of the sub base material under the bottom of the soil cells shall be 6 mm in 1200 mm. Adjust sub base material including larger pieces of aggregate under each soil cell to provide a solid base of support.

.6

For additional layers, comply with manufacturer’s requirements to correctly register and connect the soil cells together.

.7

Install Growing Medium, geogrid and geotextile curtain, rain water harvesting system and backfill as indicated on the drawings and per specification. The process of installation requires that these materials be installed and compacted together in several alternating operations to achieve correct compaction r elationships within the system.



.8

Where required install utility lines within the soil cells during the installation of the system.

.9

Where required, place the geogrid and geotextile curtain along the outside of the limit of the soil cell frames. .1

Geogrid and geotextile curtains are required between the edge of the Soil Cells and any soils to be compacted to support paving beyond the area of Soil Cells. Do not place geogrid and geotextile curtains between the edge of the Cells and any planting area adjacent to the Cells.

.2

Pre-cut the geogrid and geotextile to allow for 150 mm minimum under lapping below backfill, and 300 mm minimum overlapping top of soil cells.

.3

Where cell layout causes a change direction in the plane of the geogrid or geotextile, slice the top and bottom flaps of the material so that it lies flat on the top of the soil cells and aggregate base course along both planes.

.4

Provide a minimum of 300mm overlaps between different sheets of geogrid or geotextile.

.5

Place the geogrid and geotextile in the space between the soil cells and the sides of the excavation. Attach the geogrid to the soil cells at every soil cell t hen place the geotextile over the geogrid.

.10

Install no more than two layers of soil cell frames before beginning to install Growing Medium and backfill. Compact the Growing Medium within the soil cells and the backfill material outside the frames in alternating lifts until the desired elevations and density is achieved in both soils.

.11

Install and compact backfill material in the space between the soil cells and the sides of the excavation in lifts that do not exceed 250 mm in depth.

.12

.1

Compact backfill to minimum 95% of maximum dry density using a powered mechanical compactor. Use a pneumatic compacting tool or narrow foot jumping jack compactor f or spaces less than 300 mm wide and a 300 mm wide jumping jack compactor or lar ger equipment in wider spaces.

.2

Maintain the geogrid and geotextile curtain between the soil cells and the backfill material.

.3

Install backfill in alternating lifts with the Growing Medium inside the soil cells.

Fill the first layer or layers of frames with Growing Medium, specified in Section "Growing Medium". Install in lifts that do not exceed 250 250 mm. Lightly compact the soil inside the frames at each lift to remove air pockets and settle the soil within the frames. Refer to manufacturer’s instructions. .1

Lightly compact each lift to achieve the following test results. Gr owing Medium compaction shall be tested at each lift using a cone penetrometer to between 2 70,000 and 140,000 kg/m (100 and 200 psi) when the soil is between 12% and 20% moisture.

.2

If the Growing Medium becomes overly compacted, remove the soil and reinstall. Use hand tools or other equipment that does not damage the soil cells.

.3

Eliminate air pockets and voids. Fill each frame such that there is a minimum of 200 mm of soil over the top of the soil cells before beginning compaction.


3.9

.13

After the first two layers of soil cells have been installed, filled with Growing Medium and backfilled, proceed to install the third layer of soil cells, if required. Comply with manufacturer’s requirements to correctly register and connect the soil cells together.

.14

Continue to install and compact the Growing Medium within the soil cells and the backfill material outside the frames in alternating lifts until the desired elevations and density is achieved in both soils. .1

When using mulch, add a final layer of Growing Medium as required to bring the Growing Medium level to not more than 25 mm below the bottom of the soil cell when installed.

.2

Obtain final approval by the City for the soil installation.

.15

Leave 25 mm air space, below top layer of soil cells.

.16

Install and compact remaining backfill material such that the soil outside the limits of the soil cells is flush with the top of the installed deck.

INSTALLATION OF RAIN WATER DISTRIBUTION SYSTEM WITHIN THE SOIL CELLS .1 Install perforated rainwater distribution lines as specified in Section Rain Water Distribution System. .2

3.10


Assure that lines are laid level within the growing medium at the depths indicated on the drawings.

INSTALLATION OF GEOTEXTILE, GEOGRID, INSPECTION RISER AND AGGREGATE OVER SOIL CELLS .1 Refer to manufacturer’s instructions. .2

Overlap geogrid over the top of the soil cells, with minimum of 300mm overlap.

.3

Place geotextile over the top of the soil cells and where indicated on the drawings, extending beyond beyond the outside edge of of the excavation by at least 450 mm. Any joints must be overlapped by a minimum of 450 mm.

.4

Cut geotextile larger than the size of the soil cell area to be covered to accommodate for required conforming of the geotextile and aggregate to the soil cell contours and all required overlaps.

.5

Install 100mm solid P.V.C. inspection risers above the soil cells where indicated on the plan or directed in in the field. Install a minimum of one inspection inspection riser for each four trees. .1

.2

Place inspection risers on top of the soil cells, assemble riser and fittings to dimensions required such that the rim of the riser cap is flush with the paving. Set the rim top with a slope consistent with the slope of the pavement. .1

Adjust the location of the riser such that the center of the riser falls along the centerline of one of the soil cell slots. Cut the soil cell geotextile with an ‘X’ cut.

.2

Make a geotextile collar secured to the riser with zip ties that over lap the surrounding geotextile a minimum of 300mm. Secure in place with tape.

Brace all risers while backfill and paving is being installed to secure its location and elevation.


.6


Install the aggregate base course over the geotextile immediately after completing the installation of the fabrics and inspection risers. Work the aggregate from one side of the soil cell to the other to ensure that the fabric and aggregate conforms to the soil cell contours. Do not apply aggregate in several positions at the same time. .1

Load the aggregate from equipment that is outside the limits of the excavated area. Use small, low impact material mover such as a concrete buggy or Georgia Buggy to move aggregate over the cells. Work over material already in place. Never allow any motorized equipment of any size to operate directly on top of the soil cells.

.2

For large or confined areas, where aggregate cannot easily be placed from the edges of the excavated area, obtain approval for the installation procedure and types of equipment to be used in the installation from the soil cell manufacturer.

.3

Compact aggregate base course(s) in lifts not to exceed 150mm in depth, to minimum 95% of maximum dry density. Utilize a roller or plate compactor with a maximum weight of 450 kg. Make sufficient passes with the compacting equipment to attain the required compaction.

3.11

INSTALLATION OF PAVING ABOVE THE SOIL CELL SYSTEM .1 Place planter curb and paving material over the soil cell system as specified in Sections Concrete and Unit Pavers. Take care when placing paving or other backfill on top of the soil cell system not to damage the system components.

3.12

INSTALLATION OF ROOT BARRIERS .1 Install root barrier in accord with manufacturer's reviewed installation instructions. .2

3.13

Install with vertical root directing ribs facing inwards towards trees or plants.

INSTALLATION OF GROWING MEDIUM WITHIN THE TREE PLANTING AREA .1 Prior to planting trees, install additional Growing Medium, to the depths indicated, within the tree opening adjacent to paving supported by soil cells. .2

Remove all rubble, debris, dust and silt from the top of the Growing Medium that may have accumulated after the initial installation of the Growing Medium within the soil cells.

.3

Assure that the Growing Medium under the tree root ball is compacted to approximately 85-90% to prevent settlement of the root ball.

.4

The Growing Medium within the tree opening shall be the same soil as in the adjacent soil cells.

3.14

REPAIR OF CUT GEOTEXTILE .1 In the event that any geotextile over subgrades or the soil cells must be cut during or after installation, repair the seam with a second piece of geotextile that overlaps the edges of the cut by a minimum of 300mm in all directions prior to adding aggregate material.

3.15

PROTECTION .1 Ensure that all construction traffic is kept away from the limits of the soil cells until the final surface materials are in place. No vehicles shall drive directly on the soil cells or aggregate base course.


3.16


.2

Provide fencing and other barriers to keep vehicles from entering into the area with soil cell supported pavement.

.3

Maintain a minimum of 100 mm of aggregate base course over the geotextile material during construction.

.4

When vehicles must cross soil cells that do not have final paving surfaces installed, use construction mats and thick er aggregate layers designed to distribute vehicle loads to levels that would be expected at the soil cell surface once final paving has been installed. Use only low impact track vehicles with a maximum surface pressure under the vehicle of 2 20 kg/m , on top of the mats over soil cells prior to the installation of final paving.

CLEAN UP .1 Perform cleanup during the installation of work and upon completion of the work. Maintain the site free of soil and sediment, free of trash and debris. Remove from site all excess soil materials, debris, and and equipment. Repair any damage to adjacent materials and surfaces resulting from installation of this work.



SECTION 32 91 21 GROWING MEDIUM PAGE 1 OF 17


SUMMARY .1

.2

The work in this section includes, but is not limited to, the following: .1

Mixing and testing of Topsoil, Coarse Sand or aggregate and Pine Bark or other organic material to create Growing Medium and Structural Soil.

.2

Installation of Growing Medium and Structural Soil.

.3

Compacting and grading of Growing Medium and Structural Soil.

.4

Adding organic material to the surface layer of Growing Medium.

References: .1

The following references and standards are use herein and shall mean: .1 ASTM: American Society of Testing Materials. .2 Canadian Council of Ministers of the Environment PN1340-[2005], Guidelines for Compost Q uality. .1 .3

1.2

1.3

US Department of Agriculture (USDA) Soil Classification System

RELATED SECTIONS .1

Section 32 88 88 Soil Cells

.2

Section 32 93 00 Planting

.3

Section 32 84 10 Rainwater Distribution System

SUBMITTALS .1

Certificates: Submit Certificates: Submit certification for approval that all Growing Medium components and the Growing Medium meet all environmental standards of Ontario and the City of Toronto. Certificate shall state that all materials are within the required maximum levels of all biological and metal and chemical contaminants.

.2

Product Data: Submit Data: Submit manufacturer product data and literature for approval for Coarse Sand, Pine Bark Bark Compost and Yard Waste Compost. Provide submittal as part part of the submittal of components for the Growing Medium prior to the submission of the Growing Medium. .1

Submit the manufacturer’s particle size analysis, pH and the manufacturer’s Fines Modulus Index Index for Coarse Sand. Provide Manufactures identification and location for each Coarse Sand source.

.2

Submit the manufacturer’s Pine Bark Compost and Yard Waste Compost analysis for approval. Chemical and physical testing shall be conducted by soil laboratories accredited by The Compost Q uality Alliance (CQA) utilizing test methods specified in The Test Methods for Examination of Composting and Compost (TMECC) except as specified herein.

.3

The analysis shall include: Parameter

Testing Method

pH

TMECC 4.11A

Soluble Salt - mmhos/cm

TMECC 4.10-A

% Moisture % Dry weight Organic Matter Carbon: Nitrogen (C:N) Ratio

TMECC 5.07-A



Particle size % passing 50mm screen and 10mm screen

TMECC 2.02-B

Solvita Maturity Index Physical contaminants (man made inerts) % dry weight

Solvita TMECC 3.08-A

.3

Submit testing for chemical and biological contaminants and pathogens as required by local government regulations.

.4

Certified reports shall be from samples taken within four months of the date of the sample submission.

.3

Material source locations: Submit locations: Submit locations of Topsoil and Growing Medium material sources. The City shall have have the right to reject any material source. Submit the name, address and telephone number of the source contact, and the location of the soil source including directions to the specific f ield location on the property. Provide submittal eight weeks before the installation of Growing Medium.

.4

Samples: Submit samples of each product and material where required by the specification to the City for approval. approval. Label samples to indicate product, specification number, characteristics, and locations in the Work. Samples will be reviewed for appearance only. only. Compliance with all other requirements is the exclusive responsibility of the contractor. Delivered materials shall shall closely match the samples. Submit samples of all soil mix components a minimum of eight weeks before the installation of Growing Medium. .1

.5

Submit duplicate 4-liter samples (total 8 liters) of all Topsoil, Coarse Sand, Pine Bark Compost, Yard Waste Compost and Growing Medium in this section. .1

Samples should be labeled to include the location of the source of the material.

.2

Samples of each material shall be submitted at the same time as the product data and testing data of that material. Samples and analysis of Topsoil, and Growing Medium m ust be submitted within 28 calendar days of sampling.

.3

Each test report shall be marked with the following information:

.1 .2 .3

Date issued.

.4 .5 .6

Date, place, and time of sampling.

.7 .8

Type(s) of test

Project Title and names of Contractor and material supplier. Name of material and reference number from Part 2 of the specifications identifying the type of material. Location of material source. Testing laboratory name, address, and telephone number, and name(s), as applicable, of each field and laboratory inspector. Results of tests including recommendations of acceptable ranges of the test data f or the types of plants to be planted in the soil and recommendations for soil amendments to bring the soil to within these acceptable ranges.

.4

Samples of all Growing Medium components shall be submitted eight weeks before the installation installation of Growing Medium. Medium. Growing Medium shall be submitted no less than two weeks after the approval of the mix component.

.5

Do not submit Growing Medium for approval until all mix components have been approved by the City.

Testing Reports: Submit soil test analysis analysis report for approval for each sample of Topsoil and Growing Medium from an approved soil-testing laboratory to include the following:



.1

The testing laboratory shall be approved by the City in advance. All soil and Growing Medium tests shall be conducted by soil laboratories accredited by The Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), except as noted below. Current listing of accredited laboratories may be obtained obtained on the web at http://www.omafra.gov.on.ca/english/crops/resource/soillabs.htm. at http://www.omafra.gov.on.ca/english/crops/resource/soillabs.htm. Submit the name of the soil lab for approval prior to starting the testing process.

.2

All tests shall be performed in accordance with the current testing standards and protocols of The Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) except where otherwise noted.

.3

Particle size analysis for analysis for all Topsoil and Growing Medium including the following sand fraction gradient of mineral content: USDA Designation

Size in mm.

Gravel Very Coarse Sand Coarse Sand Medium Sand Fine Sand

>2mm 1-2 mm 0.5 -1 mm 0.25-0.5 mm 0.1-0.25 mm

Very Fine Sand Silt Clay

0.05-0.1 mm 0.002-0.05 mm <0.002 mm

.1

.4

Particle size analysis for Topsoil and Growing Medium to include sand sieve analysis shall be performed per ASTM D422 (hydrometer test) or ASTMF1632 (pipette test).

Chemical analysis including analysis including the following: .1

pH

.2

Nutrient levels by parts per million including: Phosphorus Potassium Magnesium Calcium .1

.5

Nutrient test shall include the testing laboratory recommendations for supplemental additions to the Growing Medium.

.3

Soluble salt by electrical conductivity of a 1:2 soil water sample measured in mmhos/cm.

.4

Cation Exchange Capacity (CEC).

.5

Percent of Organic Matter by dry weight as determined by ignition (Ash Burn Test or Walkley/Black Test, ASTM F1647).

.6

Report suitability of Topsoil or Growing Medium for growth of applicable planting material. Soil analysis analysis tests shall include include recommendations for normal acceptable ranges of soil chemical attributes for the type of plants included in the project in the same units as the test data.

The City may request additional Growing Medium test on different mix component ratios in order to attain results that more closely meet the mix requirements.

.6

In-Situ Compaction testing: Submit results of all compaction testing required by the specifications including the compaction testing log of penetrometer and moisture meter readings to the City for approval.

.7

Laboratory’s comments or recommendations regarding amendment requirements or procedures shall not be interpreted to prescribe or dictate procedures or quantities of soil



materials for the work of this Contract. Final approval of soil amendment procedures shall be approved by the City.

1.4

.8

The City reserves the right to require additional soil analysis at any time such additional samples of materials are deemed necessary for verification of conformance to specification requirements. Contractor shall furnish samples for this purpose upon request and shall perform testing as requested.

.9

All testing will be at the expense of the Contractor.

.10

Contractors Qualifications: Submit documentation that the installing contractor meets all the requirements of quality assurance in section 1.6.2 below

.11

Submittal checklist: At the end of this specification section, a submittal check list is provided for the contractors use. This list is a summary of the requirements and is not intended to supplant or modify the above descriptions of the requirements. Where this summary may suggest a different specific instruction, the above specification shall take precedent.

GROWING MEDIUM IN-SITU COMPACTION TESTING. .1

1.5

1.6

Installed Growing medium shall be tested in-situ with a cone penetrometer and a soil moisture meter. Penetration resistance shall be to the full depth of the installed soil profile or 750 mm which ever is less. One test shall be performed every 25 25 square Meters of Growing Medium surface area. The city may request additional testing locations. .1

The cone penetrometer shall be “Soil Compaction Tester” as manufactured by Dickey-John, and distributed by Ben Meadows www.benmeadows.com

.2

Maintain a record log of all compaction testing for submission and approval. The record log shall include the date, location, depth and pressure reading of each test. Test location data shall be plotted on a site plan

SEQUENCING AND SCHEDULING .1

General: Prior to the start of Work, Work , prepare a detailed schedule of the work for coordination with other trades.

.2

Schedule the installation of Growing Medium after the area is no longer required for use by other trades and work or protect the Growing Medium from compaction and contamination.

.3


QUALITY ASSURANCE ASSURANCE .1

Contractor is solely responsible for quality control of the Work. Work .

.2

The installer shall be a firm having at least 5 years of successful experience of a scope similar to that required for the Work, including the preparation, mixing and installation of custom Growing Medium in urban locations.

.3

Comply with applicable requirements of the laws, codes, ordinances and regulations of federal, State and municipal authorities having jurisdiction. Obtain necessary permits and approvals from all such authorities.

.4

Comply with all requirements for control of silt and sediment during soil installation work as indicated in the contract contract documents. Use any other methods and procedures requested by the City to control silt and sediment as project conditions warrant.

.5

Review of work by the City: The Contractor shall comply with the requirements of the plans and specifications regardless of r eview or lack of r eview by the City.


1.7

.1

Failure of the City to reject unsatisfactory workmanship or to notify the Contractor of their responsibility to repair and/or replace unsatisfactory work shall not constitute acceptance of the work.

.2

The City reserves the right to take and analyze, at any time, such additional samples of materials as deemed necessary for verification of conformance to specification requirements. Contactor shall furnish samples for this purpose upon request and shall perform any additional testing requested.

DELIVERY, STORAGE, AND HANDLING .1

1.8


Weather: Do not mix, deliver or place soils in frozen, wet, or muddy conditions. .1

Where construction sequencing requires work during cold weather, protect sub grades and bulk materials from freezing using covers or as needed needed heated tenting. tenting. Sub grades that are sufficiently well drained to preclude the buildup of ice may be installed and built upon during freezing weather provided the surface is cleared of snow and any ice bound material.

.2

Harvest Topsoil and prepare Growing Medium ahead of the scheduled work during periods of warm weather. Protect stockpiles of soil and Growing Medium from freezing and saturation. Remove soil from within the interior of the stockpile where soil and and Growing Medium are are not frozen. At the end of each day cover the th e exposed working face of the stockpile sufficient to keep the pile from freezing.

.2

Protect soil stockpiles from rain and washing that can separate fines and coarse material. Cover stockpiles with plastic sheeting at t he end of each workday.

.3

Protect Growing Medium stockpiles from contamination by chemicals, dust and debris that may be detrimental to plants or soil drainage.

.4

Do not use delivery or installation methods that overly mix pulverize the Growing Medium. Soil blowing equipment and “soil slinger” equipment shall not be permitted to move Growing Medium

SITE CONDITIONS .1

It is the responsibility of the Contractor to be aware of all surface and sub-surface conditions, and to report any circumstances that will negatively impact soil drainage. Do not proceed with work until unsatisfactory unsatisfactory conditions have been been corrected. Proceeding with work constitutes acceptance of existing or corrected conditions.

.2

Utilities: Determ ine location of all utilities including vaults, conduits, pipes and wires adjacent to, below or within the areas of work. Perform all work in a manner, which will avoid damage to any utility. Hand excavate near any utility.

.3

Waterproof ing: Perform work in a manner, which will avoid damage to waterproofing membrane, protection board or other structural sealing materials.

.4

Construction Sequencing: .1

Install all soils at the point in the project sequencing that the soil can be adequately protected from other work at the site.

.5

Coordination: Coordinate work with that of other trades affecting or affected by work of this Section and cooperate to assure the steady progress of work.

.6

Safety: The Contactor shall be responsible for pedestrian and vehicular safety and control all movement within and around the work site. Provide the necessary barriers, warning



devices and ground personnel needed to give safety, warning and protection to persons and vehicular traffic within the area of work including the contractor's equipment and temporary storage within the public right of way. Provide any additional items required by the City. .7

Damage: During site preparation, soil installation and protection, the Contractor shall be responsible for all damage to existing features above and below ground incurred as a result of work operations. Repairs and/or replacements shall be made to the satisfaction of the City.

.8

Protect all installed material for compaction, contamination and erosion. Install fences; utilize mulch, mats and geofabrics over the surface surface of the soil as required. In the event that any soil becomes compacted, contaminated or eroded, repair the damage using procedures required by the City.

Part 2 PRODUCTS 2.1

TOPSOIL .1

Topsoil shall be fertile, loam, sandy loam to sandy clay loam, suitable for the germination of seeds and the support of vegetative growth, which is a naturally produced soil harvested from the O or A horizon of the soil profile and meeting the following requirements. It is the intent of this specification to use naturally occurring soils available within the Toronto region. Topsoil shall meet the following criteria. .1

Chemical Analysis: .1

pH less than 7.8 and greater than 5.5

.2

Nutrient levels: Phosphorous ppm Potassium ppm Calcium ppm Magnesium ppm

10-60 80-250 <5000 100-300

.3

Soluble Salt less than 0.50 mmhos/cm

.4

Cation Exchange Capacity (CEC) greater than 20.0 meq/100gr.

.5

Percent Organic Matter between 2.5 and 5%.

.2

Topsoil shall have clay content between 15 and 23%; combined silt and clay content between 35 and 60% and gravel/ stone content of no more than 5%.

.3

Topsoil shall retain a significant portion of the soils ped structure when stockpiled at the suppliers yard. yard. At least 25% of the soil volume volume shall be soil peds larger than 25mm in diameter. Peds are defined as the clumps of soil naturally aggregated during the soil building process, by clays and soil biology. Peds of any size are permissible. .1

.4

Peds are to determined by visual approximation for both size and quantity. The City shall determine determine when soils have sufficient ped

Topsoil shall not contain materials and contaminants at levels that would be harmful to plant growth; or impair drainage, installation or maintenance of the resulting Growing Medium; or adversely impact its intended use including the following: .1

Refuse; roots; construction debris; wood or sticks larger than 25mm (1 inch) in diameter; brush; clumps of root mats of plants and/or toxic materials

.2

Lumps of clay or subsoil larger than 50mm (2”); stones larger than 75 mm (3”)


.5

2.2


.3

Deleterious substances; plant or soil pests; undesirable grasses including crabgrass or couch grass, noxious or weeds or weed seeds;

.4

The City shall determine if the quantities of any of these materials is sufficient to cause cause rejection of the Topsoil. The aggregate of all the above materials shall not exceed 5% of the total soil volume as assesed by visual inspection.

Topsoil shall be in conformance with City of Toronto Weed Control Act. The contractor shall be responsible for removing all weeds that germinate during the plant maintenance period.

.2

Topsoil shall be harvested from approved source locations that comply with all regulations governing the removal of topsoil.

.3

Topsoil may be purchased from a source of collected topsoil from development sites provided the sources of the soil stock pile is of similar textures and meets the requirements of this specification.

.4

Topsoil shall not be a soil mix including a combination of sand, fertilizer, or organic matter or compost added to mineral soil in order to meet the texture, chemical or organic requirements for Topsoil. The organic matter content of the soil shall be residue of long term, natural soil building processes and not from added organic matter or compost.

.5

Topsoil shall not be screened through sieves or screens smaller than 50mm to avoid eliminating the required soil peds.

.6

Submit source location and a list of all crops grown on the soil and any herbicides and pesticides applied over the previous three years.

.7

Submit two 4-liter samples from each Topsoil source with soil testing results. The sample shall be a mixture of the random samples taken around the source field or stockpile. The delivered sample shall represent the soil ped content in the stockpile

COARSE SAND .1

Coarse Concrete Sand, ASTM C-33 Fine Aggregate, with a Fines Modulus Index between 2.8 and 3.2.

.2

Physical Analysis: Sieve Size mm 9.5 4.75 2.36 1.18 0.60 0.30 0.15 0.075

% Passing 100 95-100 80-100 50-85 25-85 5030 0-10 <3

The results must be submitted for Fines Modulus Index, percent (%) passing for all sieve sizes. Failure to include any of the aforementioned criteria will be cause for rejection of the test report. .3

Coarse Sand shall be clean, sharp, mineral sand.

.4

Coarse Sand shall be washed to remove silt and clay particles.

.5

Chemical analysis shall be as follows: Organic matter content (% oven dry weight of soil) less than 0.5%. pH shall be less than 8.6 Soluble salt content (Conductivity) Less than 0.5 mmhos/cm for 1:2 sample to water ratio.



Coarse Sand shall not contain toxic substance content at levels harmful to plant growth. .6

2.3

Submit two four liter samples with manufacturers literature and material testing certification that the product meets the requirements. YARD WASTE COMPOST and PINE BARK COMPOST

.1

Compost shall be a stable, humus-like material produced from the aerobic decomposition, composted and cured until the maturity status complies with indices specified below. Except as specified herein, Compost shall conform to the requirements for Category A Compost as defined in the Guidelines for Compost Quality (2005), Canadian Council of Ministers of the Environment.

.2

Yard Waste Compost feedstock Compost feedstock shall be yard waste trimmings and/or source-separated municipal solid waste.

.3

Pine Bark Compost feedstock Compost feedstock shall be 98% pine trees with less than 10% combined pine wood fiber and sawdust content.

.4

Compost shall not contain debris such as sharp objects, plastics, trace elements and foreign matter in excess of that that defined for Category A Compost. Total of all stones, recognizable branches, wood chips and roots larger than 25mm in diameter shall be less than 5% by volume.

.5

Compost shall have a moisture content between 35 and 55% when blended or applied.

.6

Yard Waste Compost and Pine Bark Compost shall be composted long enough to exhibit a dark brown color, approximately Munsell colour 7.5 R; Value 3 or lower; Chroma 2 or lower. Color shall be determined by visual comparison of the sample to the “Munsell Soil Soil Color Chart”, most current edition.

.7

Compost shall have a strong aerobic (sweet) odor. Compost lacking a strong aerobic odor or which has an anaerobic (sour) or a strong pine or alcohol odor shall be rejected. Odor may be determined during the submittal sample review and at the time of any inspections of materials by the City by observation of the inspector.

.8

Certification: provide the following documentation:

.9

.1

A statement that the Compost meets all health and safety regulations.

.2

Feedstock type and percentage in the final Compost product.

Testing: Compost shall have one (1) composite sample tested from each 100 cubic meters of material intended for use in Growing Medium. The results of Compost analysis shall be provided by the Compost supplier for approval. Compost shall meet the following criteria as reported by the following laboratory tests: Parameter Range pH Yard Waste Compost 5.0 - 7.8 pH Pine Bark Compost 4.0 - 5.0 Soluble Salt < 3.5 mmhos/cm % Moisture 35-55% wet weight basis % Organic matter >35% dry weight basis Carbon to nitrogen ratio Yard Waste Compost 15:1 - 25:1 Particle Size Yard Waste Compost 95% pass through 50mm screen 25% pass through 10mm screen Particle Size Pine Bark Compost 95% pass through 20mm screen 25% pass through 6mm screen Solvita Maturity Index 6 to 8 Physical contaminants <1% dry weight basis (man-made inerts)


.10

2.4


.1

Metal content shall comply with Interim Guidelines for the Production and Use of Aerobic Compost in Ontario (2004) except for copper and zinc, which must comply with Soil, Ground Water and Sediment Standards for Use Under Part XV.1 of the Environmental Protection Act Table Table 3 (medium to fine textured soils).

.2

Pathogen reduction shall meet Section 6.0 of Interim Guidelines for the Production and Use of Aerobic Compost in Ontario (2004).

Submit two four liter samples with manufacturer’s literature and material testing certification that the product meets the requirements. GROWING MEDIUM– (for use in open planting spaces, soil trenches and Soil Cell installations below paving)

.1

A mixture of Topsoil, Coarse Sand and Pine Bark Compost mixed to the following proportions, by volume: .1 .2 .3

.2

Topsoil Coarse Sand Pine Bark Compost

40-45% 40-50% 12-15%

The Growing Medium shall meet the following parameters as measured by dry weight .1

Particle distribution: .1 .2

Total sand/gravel sized 0.25mm – 5mm: Minimum 45% Total combined silt and clay: Between 18 and 35%

.2

Organic matter: Between 3.0 and 5.0%.

.3

pH: between 6.0 and 7.8. Note to specifiers: The ph maximum of 7.8 will be acceptable for most trees and other plants in the Toronto Toronto area. However, if the design team specifies pH sensitive trees or plants, the pH maximum should be lowered to an appropriate level for those plants. Note that lower pH growing medium will cost more due to the lack of availability of lower pH components. Coordinate the specification with the design team on species requirements.

.3

.4

Chemical analysis; Acceptable ranges in PPM .1 Phosphorous ppm 10-60 .2 Potassium ppm 80-250 .3 Calcium ppm <5000 .4 Magnesium ppm 100-300

.5

Soluble salts mmhos/cm

<1.5

Mix the Growing Medium with a loader bucket to preserve Topsoil peds using the following method: .1

Mix the Coarse Sand and Compost together separately.

.2

Spread a layer of Topsoil approximately 300 mm thick and apply the required proportions of Coarse Sand/Compost mix over the Topsoil.

.3

Push the Topsoil, Coarse Sand and Compost into a pile and then drag out into a layer mixing the soil with with the bucket. Repeat the mixing action a second time to gain an approximate approximate mixture of the material. Do not over mix.

.4

This method assumes that there is an additional mixing of the materials as it is moved to the final st ockpile, placed into the delivery trucks, deposited at the project site, and spread into the planting space.

.5

This method assumes that soil will not be installed using soil blower or soli slinging equipment.


2.5


Submit two four liter samples with material testing certification that the product meets the requirements.

EXISTING SITE SOIL USED AS GROWING MEDIUM districts of Note to specifiers: There are likely many places in the neighborhood commercial districts Toronto, where the soil under the existing pavement can be reused and installed in t o the soil zones being constructed. These would be places where the underlying soil is disturbed disturbed and compacted native soils that have not been mixed with gravels or unshrinkable fills, locations where the remaining native soils are not deep subsoils with high clay or silt content, soils with very high or low pH or where the native soil has been contaminated contaminated with chemicals and or or salt. In most cases the existing soil only requires loosening the compaction and adding Yard Wast e Compost. Making the determination if this is feasible requires the examination examination of the soil conditions by a soil expert. However, often, reasonable investigation of the s oil is not possible until large areas of paving have been removed. This delay may make the decision for reuse difficult. Other considerations are project schedule and space to temporarily store soil at the site and to undertake the compost mixing operations. In tight urban sites these constraints may make reuse of soil overly expensive. The design team must evaluate all the factor s in soil reuse before pr oceeding to assume that this concept is feasible. This decision should not be be left to the contractor to decide, although although it might be left in the specification as an option provided it does not have a negative impact on the project cost. .1

Existing site soil may be used as Growing Medium at sites where the existing soil has been analyzed analyzed by an agricultural soil scientist and determ ined to be suitable for tree planting. The Urban Forestry Branch shall approve approve the use of existing soils and may add additional requirements to amend the soil where required.

.2

The following are requirements for Existing Site Soil to be used as Growing Medium.

.3

.1

Texture – USDA loam to sandy loam with combined silt and clay content between 20 and 40% and gravel not to exceed 8%.

.2

pH: between 6.0 and 7.8.

.3

Final chemical analysis adjusted to meet the requirements for Growing Medium.

.4

Soluble salts mmhos/cm <2.0

.5

Soil testing to determine the above described soil conditions shall be at sufficient intravals to accurately depict the soil quality but no less than one test per 20 cubic meters of soil.

Existing Site Soil to be reused shall be excavated to break up compaction and reinstalled at the compaction required for Growing Medium. .1

.4

Excavation, moving, stockpiling and installation of Existing Site soil shall utilize means and methods that preserve soil peds. Large compacted soil peds up to 200mm in any dimension are acceptable.

Yard Waste Compost shall be loosely incorporated to the soil at the time of installation at a rate of 20% by volume. .1

Push the Existing Site Soil into stockpiles no greater than 1.5M tall. Cover the stockpile with Yard Waste Compost of sufficient volume to roughly equal 20% of the stockpile volume. Using the bucket of a back how, drag the pile to approximately 1/3rd its height. Working Work ing from the bottom, turn the pile over one. one. Install into the soil area following the requirements for Growing Medium.


.5

2.6


.2

Fertilizer shall be added to the soil, if required to meet the chemical requirements of Growing Medium.

.3

Soil shall not be contaminated with toxic chemicals harmful to humans or plants at levels regulated by provincial or federal laws.

Submit the agricultural soil scientist report for approval. The report shall describe the extent and depth of the soil to be reused, and the soils quality relative to the required parameters. It is understood that obtaining accurate soil information in urban areas is difficult if there is paving over the soil. A preliminary soil report shall be submitted a minimum of 8 weeks prior to the installation of the soil. Once the soil has been made accessible by the construction, the soil shall be reevaluated and a f inal report submitted. The Urban Forestry Branch may alter the approval or make additional requirements based on the final soils report.

STRUCTURAL SOIL intended for use to solve specific structural problems where Note to specifiers: Structural soil is intended extending rooting space is desired but the dimensional limitations proposed structural systems such as precast panels or Soil Cells may not be flexible enough to accommodate t he dimensional requirements of the space. These may include areas beside beside and over utility lines, or adjacent adjacent to light post or other sub grade structures. In these cases structural soil can be specified specified to fill odd shaped or narrow spaces where it is desirable to have roots extend into these places or to pass through the structural soil into soil usable for rooting space beyond. Structural soil is not intended to be specified as the primary soil volume for trees nor is it to be used within any planting space not covered with paving. .1

A uniformly blended mixture of crushed stone, clay loam soil and hydrogel, mixed to the following proportion: MATERIAL UNIT OF WEIGHT Crushed Stone 100 dry weight USDA Clay Loam Soil

As determined by the test of the mix (Approx. 18 +/- dry weight)

Hydrogel

0.03 dry weight

Total moisture

10% (AASHTO T -99 optimum moisture)

.2

The mix design shall be determined by adjusting the ratio between the Crushed Stone and the Clay loam such that the percent of Clay Loam in the mix is less than 85% and more than 75% of the percent of voids in the Crushed Stone.

.3

The above formula is a patented mixture developed by Cornell University called CU Soil. The Patent is administered by Amereq, Inc; 19 Squadron Blvd, New York Cit y, NY, 10956; 800 832 8788.

.4

Crushed stone, clay loam soil and hydrogel shall meet the specifications of the patent and the requirements of Amereq, Inc. The crushed stone shall shall be from a non limestone source.

.5

Structural Soil shall be supplied by a distributor licensed by Amereq, Inc with a minimum of five years experience mixing and supplying CU Soil.

.6

Structural Soil shall be delivered at or near optimum compaction moisture content as determined by AASHTO T 99 (ASTM D 698). 698). Do not deliver or place materials in an excessively moist condition (beyond 2 percent above optimum compaction moisture content as determined by AASHTO T 99 (ASTM D 698).


2.7


Provide a two 4 liter sample with manufacturer’s literature, analysis data, and material certification that the product meets the requirements.

CHEMICAL ADDITIVES .1

Chemicals and other materials designed to increase soil fertility. All products shall be delivered to the site in unopened containers and stored in a dry enclosed space suitable for the material and meeting all environmental regulations. All products shall be freshly manufactured and dated for the season in which the products are to be used. .1

Fertilizer for planting shall be organic fertilizer, as defined under the Canadian Fertilizer Act.

.2

Fertilizer selections shall be based on the recommendations of the soil test. Submit manufacturer’s product literature.

Part 3 - EXECUTION 3.1

3.2

SITE EXAMINATION .1

Examine the surface grades and soil conditions for any circumstances that might be detrimental to soil dr ainage, such as uneven sub grades and waterproofing that m ay hold or pond water, deposits of construction-related waste or soil contamination, storage of material or equipment, soil compaction or poor drainage. Confirm that all utility work and installation of planter drainage has been com pleted and tested. Examine the grading, verify all elevations. C

.2

onfirm that all other work in the area of Growing Medium installation is completed. Notify the City in writing of any unsatisfactory conditions.

COORDINATION WITH PROJECT WORK .1

3.3

3.4

The Contractor shall coordinate with all other work that may impact the completion of the work. Protect installed Growing Medium from compaction by other other trades.

GRADE AND ELEVATION CONTROL .1

Provide grade and elevation control during installation of Growing Medium. Utilize grade stakes, surveying equipments and other means and methods to assure that grades and contours conform to the grades indicated on the plans.

.2

Maintain grade stakes until the grades have been viewed by the City.

SITE PREPARATION PREPARATION .1

In areas not above structure, excavate to the proposed sub grade. Maintain all required angles of repose of the adjacent materials as shown on the drawings or as required to support adjacent materials or structures. Do not over over excavate compacted sub grades of adjacent pavement or structures. Remove all construction debris debris and material.

.2

Confirm that the sub grade is at the proper elevation and compacted as required. Sub grade elevations shall slope parallel to the finished gr ade and/or toward the subsurface drain lines as shown on the drawings.

.3

Do not proceed with the installation of Growing Medium, until all utility work in the area has been installed.

.4

Do not begin Growing Medium installation until all subsurface drainage, and irrigation main lines shown on the drawings are viewed and approved by the City.


3.5

3.6


Protect adjacent walls, walks and utilities from damage or staining by the soil. Use 12mm plywood and or plastic sheeting as directed to cover existing concrete, metal and masonry work and other items as directed during the progress of the work. .1

Clean up any soil or dirt spilled on any paved surface, including at the end of each working day.

.2

Any damage to the paving or architectural work shall be repaired by the contractor at the contractor’s expense.

GROWING MEDIUM INSTALLATION (SOIL CELLS) .1

Install and compact Growing Medium within Soil Cells in accordance with Specification Section Soil Cells.

.2

Coordinate the installation of the water harvesting system and drain lines within the Soil Cells.

GROWING MEDIUM INSTALLATION (All Growing Medium except within Soil Cells) .1

Prior to installing any Growing Medium, the City shall approve the condition of the sub grade and the previously installed sub grade preparation and the installation of subsurface drainage material.

.2

In areas of soil installation above existing subsoil, till the Growing Medium into the bottom layer of subsoil. .1

Loosen or till the subsoil of the sub grade to a depth of 50-75 mm with a backhoe or other suitable device. The use of soil blowing equipment equipment or “soil slinging” equipment is not permitted to install Growing Medium.

.2

Spread a layer of the specified Growing Medium 50-75mm deep over the sub grade. Thoroughly till the Growing Growing Medium and the sub grade together.

.3

Immediately install the remaining Growing Medium in accordance with the following specifications. Protect the tilled area from traffic. DO NOT allow allow the tilled sub grade to become compacted.

.4

In the event that the tilled area becomes overly compacted, re-till the area again prior to installing the Growing Medium.

.3

Install the remaining Growing Medium in 300-400mm lifts to the required depths. Work out from the installed soil such that equipment does not have to pass over the installed soils.

.4

The depths and grades shown on the drawings are the final grades after settlement and shrinkage of the organic material. The contractor shall install the Growing Medium Medium at a higher level to anticipate this reduction of Growing Medium volume depending upon predicted settling properties for each type of Growing Medium as indicated on the drawing.

.5

Utilize grading and earth moving equipment that uses low impact tracks that is rated to 2 equipment used to install exert a static force on the ground of no more than 20 kg/M . All equipment soil shall have buckets equipped with teeth to loosen soil c ompaction.

.6

When any equipment passes over previously prepared subgrade or installed soil it shall reverse out of the soil area over the same path dragging the teeth of the bucket over the tracks to break surface compaction created by the equipment.

.7

Coordinate the installation of water harvesting system and drain lines within the Growing Medium.

CITY OF TORONTO TREE PLANTING SOLUTIONS IN HARD BOULEVARD SURFACES 3.7

GROWING MEDIUM COMPACTION (All Growing Medium except within Soil Cells) .1

Lightly compact each 300-400mm lift to achieve the following test results. .1

Growing Medium compaction shall be tested at each lift using a cone penetrometer to between 70,000 and 140,000 Kg/M2 (100 and and 200 psi) when the soil is between 12 and 20% moisture.

.2

Compact Growing Medium under the root balls of all trees to between 200,000 and 250,000 Kg/M2 (275 and 350 psi) when the soil is between 12 and 20% moisture t o reduce settlement and provide a stable base for the tree as indicated on the drawings.

.3

Maintain moisture conditions within the Growing Medium during installation to allow for satisfactory compaction. Suspend installation operations if the Growing Medium becomes wet. Do not place Growing Medium on wet or frozen sub grade.

.4

Provide adequate equipment to achieve consistent and uniform compaction of the Growing Medium. Use the smallest equipment equipment that can reasonably perform the task of spreading and compaction.

.5

Using the penetrometer and the moisture meter, test the compaction levels in the installed growing medium.

.6

3.8


.1

Testing shall be performed by the contractor.

.2

Record the test results on a soil compaction testing log. This report shall include the location of the test, the depth of the test measures from the proposed finished grade, the penetrometer reading, the moisture meter reading, The penetrometer reading and the moisture meter reading.

.3

Submit the compaction log to the City at the end of soil installation period. The soil compaction log shall be kept current and available at the site for review at all times.

At the end of the installation of the soil and prior to the installation of Organic Matter and plants, take a minimum of four undisturbed soil samples from locations selected by the City to determine determine bulk density. Submit test results for approval.

INSTALLATION OF STRUCTURAL SOIL .1

Confirm that the sub grade material is graded towards the drain line locations and fully compacted to 95% of maximum dry density.

.2

Install Structural Soil in 150-200mm lifts and compact each lift. .1

Compact Structural Soil to not less than 95% of peak dry density from a standard AASHTO compaction curve (AASHTO T 99). No compaction shall occur when moisture content exceeds maximum moisture content for optimum compaction as stated in the proctor test. Delay compaction 24 hours hours if moisture content exceeds maximum allowable and protect Structural Soil during delays in compaction with plastic or plywood as directed by the City.

.2

Test the density of Structural Soil with suitable testing equipment undertaken by a qualified geotechnical soil testing lab.

.3

Bring Soil Structural Soil to finished grades as shown on the Drawings.

.4

Fine grading: Adjust the finish grades to meet field conditions as directed. .1

Provide smooth transitions between slopes of different gradients and direction.

.2

Fill all dips and remove any bumps in the overall plane of the slope.

.3

The tolerance for dips and bumps in Structural Soil areas shall be a 50mm deviation from the plane in 2000mm.


3.9

3.10

Immediately after installation of each section of Structural Soil, cover the area with 4 mil plastic sheeting sufficient to keep the material from being contaminated or washed during rain events. Maintain all protection protection until the installation installation of the paving paving above. Remove all plastic sheeting prior to installing the paving above the Struct ural Soil.

PROTECTION .1

Protect Growing Medium from compaction and contamination by dust, debris, and any toxic material harmful to plants or humans after placement. Any area, which becomes compacted, shall be tilled to a depth of 150mm. Any uneven uneven or settled areas shall be filled and re graded.

.2

Phase the installation of the Growing Medium such that equipment does not have to travel over already installed Growing Medium.

GROWING MEDIUM FINE GRADING .1

The City shall view all rough grading prior to the installation of Organic Matter, fine grading, planting, and mulching.

.2

Set grades at time of installation high enough relative to the type of Growing Medium and settlement anticipated so that the Growing Medium will be at the correct grades after the 12 month settlement period. .1

This specification assumes that initial soil settlement during the first 12 months after installation will be between between 10 and 15% of the installed soil depth. Assure that the soil is mounded sufficiently high enough to accommodate this settlement.

.2

At the end of the planting warrantee period, if grades have settled greater than 5% of the soil depth below the grades shown on the drawings, reset the grades to the final grades shown on the grading plan.

.3

Adjust the finish grades to meet field conditions as directed.

.4

Provide for positive drainage from all areas toward the existing inlets, drainage structures and or the edges of planting beds. Adjust grades as directed to reflect actual constructed field conditions of paving, wall and inlet elevations. Notify the City in the event that conditions make it impossible to achieve positive drainage.

.5

Provide smooth transitions between slopes of different gradients and direction. Modify the grade so that the finish grade is flush with all paving surfaces or as directed by the drawings.

.6

Fill all dips and remove any bumps in the over all plane of the slope. .1

.7

3.11


The tolerance for dips and bumps in shrub and ground cover planting areas shall be a 25mm deviation from the plane in 2000mm.

Restore all grades after the installation of plants. Rem ove any excess soil removed during the planting process.

INSTALLATION OF YARD WASTE COMPOST (In areas of growing medium greater than 4 sq M in area, not covered by paving) .1

In all areas of Growing Medium in open planting beds, after the specified Growing Medium is installed, and just prior to the installation of tree, shrub or groundcover plantings, spread 100mm of Yard Waste Compost and roto-till into the top 150mm of the Growing Medium. Restore grades after tilling.


3.13

3.14


CLEAN-UP .1

During installation, keep pavements clean and work area in an orderly condition.

.2

Keep the site clear of trash and debris at all times. Immediately dispose of wrappings or waste materials associated with products necessary for the completion of the work.

.3

All trash and debris shall be kept in a central collection container. Do not bury trash and debris in back-fill.

.4

Once installation is complete, remove any excess soil from pavements or embedded fixtures.

PROTECTION DURING CONSTRUCTION .1

The Contractor shall protect work and materials from damage including: compaction, contamination, and erosion due to operations by other Contractors or trespassers. Maintain protection during installation until acceptance. acceptance. Treat, repair or replace damaged Growing Medium installation work immediately.

.2

Till compacted Growing Medium and replace Growing Medium that has become contaminated as determined by the City. Gr owing Medium shall be tilled or r eplaced by the Contractor at their own expense.

REPAIR OF SETTLED GROWING MEDIUM .1

At the end of twelve months after the date of substantial completion of the Growing Medium installation work, inspect the site and restore any areas where the gr ades have settled beyond the elevations shown on the drawings by an amount greater than 5% of the soil depth. .1

In shrub planting areas where the settlement is 75mm or less, remove the mulch, top dress the area with the specified Growing Medium and re-mulch. All ground cover areas and shrub planting areas where the settlement is greater than 75mm remove the mulch and plants, add the specified Growing Medium, re-plant and re-mulch.




Contractors Submittal Checklist Refer to 32 91 21 specification sections cited for exact requirements. √ Spec # Item Certificates 1.3.1 Certificate that all growing medium components and the growing medium meet all environmental standards. Product Data 1.3.2 Product data: Coarse Sand 1.3.2 Product data: Pine Bark Compost 1.3.2 Product data: Yard Waste Compost Material Source Locations 1.3.3 Location of all topsoil and growing medium sources Samples 1.3.4.1 Two 4 liter samples: Topsoil / submitted with required testing results 1.3.4.1 Two 4 liter samples: Coarse sand / submitted with required testing results 1.3.4.1 Two 4 liter samples: Growing medium / submitted with required testing results 1.3.4.1 Two 4 liter samples: Pine Bark Compost / submitted with with required testing results 1.3.4.1 Two 4 liter samples: Yard Waste Compost / submitted with with required testing results Testing Reports 1.3.5.4 Particle size analysis: Topsoil including Sand Fractions 1.3.5.4 Particle size analysis: Growing Medium including Sand Fractions 1.3.5.5 Chemical analysis: Topsoil 1.3.5.5 Chemical analysis: Growing Medium w/ lab recommendations for fertilizer applications 1.3.6 In-Situ Compaction Testing: Installed Growing Medium Contractors Qualifications 1.3.10 Documentation of Contractor’s Qualifications


SECTION 32 93 00 PLANTING PAGE 1 OF 15


GENERAL INSTRUCTIONS .1

1.2

Read and be governed by Conditions of the Contract and Sections of Division 1.

RELATED WORK .1

Related Sections include the following: .1

1.3

SCOPE OF WORK .1

This section includes the supply and installation of the following: .1 .2

1.4

Supply and installation of trees and plants. Regular maintenance of plants for duration of warranty period.

REFERENCE STANDARDS .1

1.5

Section 32 91 21 – Growing Medium

All trees shall be in accordance with the Metric Guide Specification for Nursery Stock most current Edition of the Canadian Nursery Trades Association except where specified otherwise.

QUALITY CONTROL .1

Plant Installer Qualifications: All planting work shall be performed by an experienced contractor who has completed planting work similar in material, design, and extent to that indicated for this project and with a record of successful landscape establishment. .1

.2

The plant installation contractor shall have a minimum of 5 years of experience with the installation of soils and plants and large trees in urban conditions similar to the scope of this project.

Plant inspections: .1

The City may inspect plants at any time from initial plant selection through final acceptance at the end of the warrantee period.

.2

Any plant inspection, except the final acceptance, shall not be considered as accepting any plant. It is understood that plant conditions change with time and inspections of plants may miss critical, but difficult to observe conditions within the plants structure or root ball.

.3

Failure of the City to inspect any plant shall not absolve the contractor of responsibility to meet all the requirements of these specifications.

4.

Plant inspections may result in field reports and instructions to the contractor to undertake modifications to processes, procedures or plant maintenance,



necessary to maintain healthy plants. Some of these instructions, such as the need to better protect plants or modify watering rates and timing may be time sensitive in order to be effective. .1

.2

.3

.4

Plants: .1

All plants shall conform to the varieties specified in the plant list and be legibly tagged with their proper name and size. No substitutions will be accepted without written approval by the City.

.2

Imported plants must be accompanied with necessary permits and import licenses. Conform to federal and provincial regulations.

Monitoring tree root ball and planter soil moisture: .1

The Contractor shall monitor the moisture levels in root balls and the planter soil and assure that they are sufficiently moist for optimum root growth and plant health.

.2

The Contractor shall maintain, in operating condition, a soil moisture meter, at the site, at all time they are working to measure root ball and soil moisture. .1

.3

1.6

1.7

The contractor shall respond, in writing, to all field reports and instructions from the City within 24 hours of receipt of any field report or instructions with a confirmation of the receipt of the field report or instruction and how and when the contractor will respond to the request. Instruction to modify watering rates shall be implemented within 48 hours of the receipt of the request of for modifications.

The moisture meter shall be a General Digital Moisture Meter available from Ben Meadows, www.benmeadows, item number 160670, or approved equal.

Moisture within the root balls and the planter soil adjacent to the root ball shall be maintained between 10 and 20% as measured by the General Digital Moisture Meter. If an alternate moisture meter is approved, the meter reading scale shall be interpolated to the moisture reading scale of the General Digital Moisture Meter.

Submittals .1

Maintenance Instructions: Submit instructions on maintenance procedures to be followed after end of specified maintenance period.

.2

Submit 1kg sample of Crushed Granite Mulch to Engineer for approval before installation.

.3

Submit the name, contact information and qualifications of the plant Installer for approval by the City. Submittal shall include the names and contact information of a minimum of five project references that best represent the firm's qualifications. All representative work shall have been completed within the previous five years.

.4

Submit, for approval by the City, the names and contact information of the grower of all plant sources. Plants shall not be obtained from a re-wholesale supplier.

PRODUCTS DELIVERY, STORAGE AND HANDLING


.1


After harvesting and prior to shipping any balled and burlapped trees from the growing nursery, notify the City to allow for an inspection of the plants at the growing nursery to assure that all harvesting requirements have been satisfied. .1

Trees shall be spaced such that the City may have access to the root balls of each tree to check the position of the structural roots and the presence of circling and adventitious roots. The contractor shall remove burlap and soil from the top of any root ball requested by the City for the purpose of this inspection.

.2

All trees shall be inspected by the Contractor for damage in transit. No defective material shall be delivered to the site. Material subsequently damaged shall be removed from the site immediately.

.3

All trees may be reviewed by the City at the site and prior to planting. The contractor shall make each root ball accessible to the City by spacing the plants in the storage area such that they can be viewed from all angles. .1

Trees shall be spaced such that the City may have access to the root balls of each tree to check the position of the structural roots and the presence of circling and adventitious roots. The contractor shall remove burlap and soil from the top of any root ball requested by the City for the purpose of this inspection.

.2

Trees that were not harvested correctly at the nursery shall be rejected and alternate replacement trees provided.

.3

In the event that the City is unable to make this inspection, plants may still be rejected at any time if it is found that they do not meet the specification requirements.

.4

Label manufactured, processed or otherwise prepared materials that are packaged to indicate manufacturer, contents, weight, and a detailed description description of the material. If delivered in bulk, submit affidavits giving information required as specified for labels and certifying that materials meet specified requirements. Store and protect fertilizer, limestone, bone meal, mulching materials, and similar products to prevent damage from moisture.

.5

No plant shall be accepted when the ball of earth surrounding its root system has been cracked or broken prior to or during planting or after the burlap, staves, ropes or platform required in transplanting has been removed.

.6

Transport plants with branches tied to prevent damage, and padded to avoid abrasion from equipment. All parts of the plant including the branches and root ball shall be covered with a tarp at all times during transit. Moisten the branches and root balls of of each tree after loading on the truck, and immediately prior to departure. For shipping distances greater than three hours, mist the trees and root balls in transit every three ours.

.7

Schedule delivery transit for all trees in leaf to occur at night or the early morning hours. Do not deliver trees in leaf on days when daytime high temperatures are predicted to be above 28 degrees Celsius.

.8

Prevent drying out of roots, root balls, trunks, branches, and leaves of plants from time of harvest until they are are planted. While temporarily stored at site, protect them with Bark Mulch or straw, or similar materials and kept moist. Mist plant tops regularly such that plant tops remain moist. Water root zones to maintain water levels in the root zone



above wilt point but below soil saturation considered to be a moisture reading of between 10 and 20% as measured by the General Digital Moisture Meter. .1

.9

1.8

If deciduous trees are moved when in leaf, spray with an approved anti-desiccant per manufacturer’s recommendations at nursery no greater than 48 hours prior to digging, and again two weeks after after transplanting. Spraying should take place in early morning hours with foliage at maximum turgidity.

Job Conditions .1

1.9

Installation of Work of this Section shall be performed under weather conditions and in suitable growth season for each specified plant, and as approved by Engineer.

Acceptance of the Work .1

The contractor is responsible for review and acceptance of the plant material at the source and – once delivered to the site – for conformance with the contract drawings. Any material that does not m eet the requirements as stipulated here sh ould be flagged and the City notified.

.2

Acceptance of plant material by the City shall be for general conformance to specified size, character and quality and not relieve the Contractor of responsibility for full conformance to the contract documents, including correct species.

.3

The City will inspect all work for substantial completion upon written request of the Contractor. The request shall be received at least ten calendar days before the anticipated date of inspection. .1

.4

1.10

Any trees in leaf that are to be stored longer than 48 hours must be placed within a shaded storage area or covered with a mesh tarp.

For plants that are dormant at the time of the acceptance inspection, the City may elect to postpone the acceptance of these plants until the next growing season when the plants are actively growing and can be evaluated for viability.

The Contractor is responsible for the condition and quality of work and materials during construction, and until Acceptance. Contractor shall bear the total cost of replacing any and all plant material until the date of acceptance.

Warranty .1

All plants shall be guaranteed for a period of two years following written acceptance of the work by the City in accordance with the General Conditions of the Contract and as modified by this section, and shall be alive and in vigorous growth at the end of the guarantee period as determined by the City. .1

Plants shall be healthy, free of pests and disease, and in flourishing condition at the end of the warranty warranty period. Plants shall be free of dead dead and dying branches and branch tips, and shall bear foliage of normal density, size, and color for the species.

.2

Plants shall be deemed defective that are not in a vigorous, thriving condition including; plants that are dead; have had more than 25% of their branches die or removed; have had a major branch or side of the plant removed such that current or future aesthetic appeal or structural integrity of the plant is compromised; are diseased or insect infested to an extent that cannot be treated; or do not produce leaves and or annual branch tip extensions that are normal to the species, as



determined by the City during or at the end of the warranty period. Plants that are defective shall be replaced. .3

When the work is accepted in parts, the warranty periods shall extend from each of the partial acceptances to the terminal date of the last warranty period. Thus, all warranty periods shall terminate at one time.

.4

The Contractor is exempt from replacing plants, after Acceptance and during the warranty period, that are removed by others, lost or damaged due to occupancy of project in any part, lost or damaged by a third party, vandalism, or any natural disaster.

.2

All plants that, in the opinion of the City, are defective or not in a healthy growing condition, as defined above, shall be replaced by the Contractor at his own expense as soon as weather conditions permit; and within the specified planting period; and prior to terminating his responsibilities under this Contract.

.3

All replacements shall be plants of the same size and variety as specified. The cost or replacement plants including delivery, and installation shall be borne by the Contractor, except for replacement resulting from theft, vandalism, or carelessness on the part of others. The City shall be the sole judge in case of dispute regarding responsibility for replacement of plants.

.4

At the end of the warranty period, the City shall inspect all warranted work, upon written request of the Contractor. The request shall be received at least ten calendar days before the anticipated date for final inspection.

.5

The warranty of all replacement plants shall extend for an additional two-year period from the date of their acceptance after after replacement. In the event that a replacement plant is not acceptable during or at the end of the said extended warranty period, the City may elect one more replacement items or credit for each item. These second replacement items are not protected under a warranty period.

.6

Final Acceptance will be given only when all the requirements of this specification have been met.


Plants - General .1

Provide trees and plants of quantity, size, genus, species, and variety or cultivars as shown and scheduled in contract documents. Type of root preparation, sizing, grading and quality shall comply with Metric Guide Specification for Nursery Stock most current Edition, except where more stringent requirements are stated in these specifications. .1

All trees shall be certified by the grower to have had all girdling roots above the main structural roots removed including any girdling roots within the interior of the root ball resulting from loose soil on top of the ball or from previous propagation practices or smaller containers.

.2

Source of plants: gr own in Zone 5 in accordance with Agriculture Canada Plant Hardiness Zone Map.

.3

Plants: freshly f reshly dug, free of disease, insects, defects or injuries and structurally sound with strong fibrous root system and densely foliated, root pruned regularly, but not later than one growing season prior to arrival on site.

.4

Trees (general): Tr ees shall have straight trunks, well and characteristically branched for species. All trees shall have a central leader to the top of the tree and branches shall be



evenly spaced along the trunk. Trees with co-dominant leaders shall be pruned to remove or suppress one of the co-dominant leaders as directed by the City. Trees with clusters of branches in the bottom half of the canopy, caused by the growers pruning the tree to force a denser canopy, shall be rejected. .5

Measure plants with branches in normal position, finish grade to top of main body of plant, not from branch tip to branch tip or from root base to branch tip. Caliper dimension shall refer to diameter of trunk measured 300 mm above the natural ground line. .1

The natural ground line shall be defined as the point where the trunk begins to flare into several roots forming the root collar and where the trunk bark texture transitions into root bark texture. A single large root emerging perpendicular from the trunk above the trunk flare shall be considered adventitious and removed. The swelling of the trunk at the point of a previous graft is not the trunk flare.

.6

Plants larger than specified will be accepted without liability to extra charges if approved by the City, and they meet all specified requirements for their size and root balls.

.7

Plant varieties and quantities required for the Project are specified in a plant schedule on the Planting Plan and the specific numbers of plants is indicated indicated on the planting plan. In case of discrepancy in quantity between the Planting Plan, Plant Schedule, or unit price schedule, the quantity of plants drawn on the Planting Plan shall take precedence.

.8

If a range of size is given, no plant shall be less than the minimum size and not less than 50 percent of the plants shall be as large as the maximum size specified. The measurements specified are the minimum size acceptable and are the measurements after pruning, where pruning is required.

.9

Plants shall have outstanding form; symmetrical, with an even branch distribution, densely foliated and/or budded, and a strong, straight distinct leader where this is characteristic of the species. Plants that meet the measurements specified, but do not possess a normal balance between height and spread, shall be rejected. The City shall be the final arbiter of acceptability of plant form.

.10

Provide healthy, vigorous stock, grown in a recognized nursery in accordance with good horticultural practice and reasonably free of significant disease, insects, eggs, larvae, and defects such as knots, scrapes, broken or split branches, fresh limb cuts, sunscald, injuries, abrasions, or disfigurement. All graft unions shall be completely healed. All graft unions shall be visible above the soil line

.11

Plants shall not be pruned before delivery. Trees, which have a damaged or crooked leader, or multiple leaders, unless specifically specified, will be rejected. Trees with abrasions of the bark, sunscalds, disfiguring knots, or fresh cut of limbs over 25 mm, which have not completely callused, will be rejected.

.12

All trees shall be dug prior to leafing out (bud break) in the spring or after plants have gone dormant in the fall except for the plants known to require spring transplanting, which are only to be dug prior to leafing out in the spring. Plants to be shipped or installed when in leaf shall be pre-dug prior to bud break and stored at the grower’s nursery in shaded, irrigated areas with their root balls covered covered in Bark Mulch. Trees shall be stored with the central leader in a vertical position

.13

Submit the growers certification that all trees have been root pruned; all girdling and circling roots above the top structural roots have been removed; and that all soil has been removed above the natural ground line of the tree prior to digging and harvesting the trees.


Plants - Balled and Burlapped Trees .1

2.3

.1

Prior to digging each tree check for the location of the natural ground line; as defined in paragraph “Plants General: subparagraph .5 above; and the depth of the first main structural roots within the root ball area. Using hand tools remove the soil around the trunk of the plant to locate the position and depth of the structural roots. The City may randomly check individual trees including removing soil from the base of the trunk to inspect roots.

.2

A minimum of three radial roots shall be found in each plant. The top structural roots shall be defined as large woody roots roughly radial to the trunk and at approximately the same depth with a diameter greater than ½ of the trunk caliper. Adventitious and circling roots above the top structural roots shall be removed and the plant shall be rejected if these roots are of sufficient number or size that removal will compromise the future health of the plant.

.3

Apply a 25 mm diameter, dot of paint or permanent marker on the north side of all trees 300 mm above the natural ground line.

.4

Prior to digging any tree, using hand tools, carefully removed the soil from the top of the root ball to the natural ground line. . Care must be exercised not not to damage the bark of the root flare and the top of the structural roots.

.5

Plants shall be burlap wrapped either using Metric Guide Specification For Nursery Stock, most current edition, drum lacing technique or a wire basket. If wire baskets are used, a low profile basket shall be used. A low profile basket is defined as having the top of the highest loops on the basket no less that 100 mm and no greater than 200 mm below the shoulder of the root ball.

.6

Twine and burlap used for wrapping the root ball shall be natural, untreated, biodegradable material.

.7

Apply 3mm thick, wax sealed, corrugated cardboard trunk protection around the trunk of the tree from the top of the root ball to the first branch. Cardboard shall be coated to reduce water penetration, and fabricated for this application. Secure the cardboard with biodegradable twine.

Trees that have been grown in a container or which are placed in a container at the end of the growing period, (containerized trees) shall not be permitted.

Water .1

2.5

All Trees shall be field grown and dug balled and burlapped and shall be harvested with the following modifications to standard nursery practices.

Plants - Container Grown Trees .1

2.4


Potable and free of impurities that would inhibit plant growth.

Tree Guying Material .1

Tree guying to be flat woven polypropylene material, 20mm wide, 400 kg breaking strength. Color to be Green. Product to be ArborTie, manufactured by Deep Root Partners, L.P. (800) 458-7668, or approved equal.

.2

Dead man shall be 89mm x 89mm x 1200mm untreated wood #3 or better SPF.

.3

Stakes shall be 35mm x 35mm x 1800mm untreated hardwood stakes, tree of knots. Sharpened at one end with an approximately 60-degree angle point.

.4

Submit manufacturers’ product data for approval.


2.6

Crushed Granite Mulch (inorganic mulch within tree spaces) .1 .2

2.7

Crushed granite; size - 19mm +/-;.color – Caledonia grey or approved equal. Submit manufacturers product data, and a 1-kilo sample for approval.

Bark Mulch .1 .2

2.7

2.8

2.9


Shredded hardwood bark mulch. Submit manufacturers product data, and a 1-kilo sample for approval.

Anti-desiccant .1

Anti-desiccant shall be emulsion type, film-forming film-form ing agent similar to Dowax by Dow Chemical Company, or Wilt-Pruf by Nursery Specialty Products, Inc., Croton Falls, New York, designed to permit transpiration but retard excessive loss of moisture from plants. Deliver in manufacturer’s fully identified containers and use in accordance with manufacturer’s instructions.

.2

Submit manufacturers product data for approval.

Tree Bark Protector .1

Tree Bark Protectors shall be black extruded resin mesh, 100mm diameter, 1500mm long. As manufactured by Industrial Netting, Minneapolis, MN, USA or approved equal

.2

For trees where the distance from the top of the rootball to the first branch is less than 1500mm, cut the tube to the required length.

.3

Fasten the split side of the Tree Bark Protector together in three places with black plastic tape.

.4

Submit manufacturers’ product data for approval.

Bike Warning Sign .1

120mm x 120mm x 1.5mm thick. black plastic sign with with white coating on face engraved text (serif font, centre justified, capitalized letters, 6 lines) reads: LOCKING OF / BICYCLES / PROHIBITED / BICYCLES WILL / BE REMOVED AT / OWNER’S RISK Only the word ‘PROHIBITED’ is bold.

.2 .3

2 holes punched at top and 2 at bottom, approx. approx. 5mm dia. Black cable zip ties through the holes horizontally and attached to the black plastic plastic mesh Tree Bark Protector.



PART 3 - EXECUTION 3.1

SITE EXAMINATION .1

3.2

PRE PLANTING MEETING .1

3.2

Examine the surface grades and soil conditions for any circumstances that might be detrimental to plant growth, such as deposits of construction-related waste or soil contamination, storage of material or equipment, soil compaction or poor drainage. Examine the grading, verify all elevations, and notify the City in writing of any unsatisfactory conditions.

Prior to the start of planting attend a pre planting meeting with the City to review the planting requirements and inspect the conditions of the planting area. During this meeting and in the presence of the City, the contractor shall install one tree to serve as the example of a tree that meets all the requirements of this specification.

PLANTING SEASON .1

Planting shall only be performed when weather and soil conditions are suitable for planting the materials specified in accordance with locally accepted practice. Install plant materials during the planting time as described below unless otherwise approved in writing by the City. In the event that the contractor request planting outside the dates of the planting season, approval of the request does not change the requirements of the warranty. Deciduous Trees except those known to require spring only transplanting: March 1 - June 15 and September 1 – October 30 Deciduous Trees known to require spring only transplanting: March 1 - June 15 The Toronto Department of Urban Forestry shall determine which trees shall require spring only transplanting.

.2

3.3

No plant shall be harvested or transported from the time of bud break until the newly formed leaves are fully developed and matured. Any plant to be planted planted during the spring planting season after the emergence of leaves, shall be harvested prior to bud break and stored in a partially shaded area, protected from winds. The root ball shall be kept moist and the top of the plant misted daily until the appropriate time of shipping. Plants to be planted in the fall planting season shall not be harvested until after August 15.

FINAL INSPECTION OF ROOT BALLS .1

The contractor shall inspect each plant after delivery and prior to installation for damage of other characteristics that may cause rejection of the plant. Notify the City of any condition observed.

.2

Note the location of the white dot on the tree base and record the distance from the center of the dot to the top of the root ball. The white dot should be approximately 300mm above the top of the soil within the root ball at the point where the soil meets the trunk. Note any discrepancies discrepancies from the required dimension and immediately notify the City if the distance is greater than +/- 50mm. Trees that do not comply with with the required



remediation of the root ball soil level may be rejected, or the City may direct the contractor to remove soil from the top of the structural roots or may reject the tree. 3.4

PREPARATION OF PLANTING BEDS .1

3.5

SOIL COMPACTION UNDER TREE ROOT BALLS .1

3.6

Preparation of planting beds is specified in Section Growing Medium and as indicated on details.

Prior to placing any tree assure that the Growing Medium under the root ball is compacted to between as required in section “Growing Medium” for the entire depth of the Growing Medium. If there is more than 300mm of under compacted Growing Medium under the root ball, excavate the first 300mm of Growing Medium and compact the lower layer of Growing Medium prior to compacting the top 300 mm Growing Medium below the root ball.

PLANTING .1

Final location of all plants to be approved by Engineer prior to installation.

.2

Trees: .1

Excavate the planting hole approximately 200mm wider than the actual root ball diameter or to the edge of the planting space and to the depth of the root ball. Do not over excavate.

.2

Set shoulder or the top of the outer edge of the root ball at the elevation of the proposed finish soil grade. Consult the grading plan and utilize a builders level or transit to determine the grade at the tree grade. For trees on sloped surfaces, set the top of the outer edge of the root ball at the average grade around the tree. Set the plant plumb and in the location indicated on the plan and approved by the City. The root flare and tree graft, if applicable, shall shall be visible at the top of the root ball, above the grade. Do not place soil on top of the root ball.

.3

Trees shall be oriented so their north side, as marked by the white dot on the trunk in the nursery, faces north. north. The City may require trees to be oriented slightly in another direction based on the form of the tree or other conditions.

.4

When set, brace root ball by tamping backfilled soil around the lower portion of the root ball. Place additional backfill around base and and sides of ball in 150mm lifts. Work each lift to settle backfill backfill and eliminate eliminate voids and and air pockets. When excavation is approximately two-thirds full, water thoroughly before placing remainder of backfill. Ropes or strings on top of of ball shall be cut and and shall be pulled back. Burlap or cloth wrapping shall be cut and removed from at least the top half of the root ball. The top horizontal ring of support wire baskets baskets shall be cut and removed entirely from the top half of the wire basket. Folding the burlap or wire basket down into the soil will not be acceptable.

.5

Repeat watering until no more is absorbed. W ater again after placing final layer of backfill.


3.7

3.8

3.9


.3

Remove all nursery plant identification tags and ribbons. The City’s seals are to remain on plants until the end of the warranty period, or as directed. The Contractor shall remove the City’s seals at the end of the warrantee period.

.4

Dispose of burlap, wire and container material off site.

TREE BARK PROTECTOR .1

Apply the Tree Bark Protector to each tree using the specified black plastic tape in three places to connect together the open sides of the mesh tube.

.2

Apply the specified “Bike warning” sign using black plastic “zip ties” to each Tree Bark Protector. Cut off any excess tie material extending past the lock end of of the tie

TREE GUYING .1

Maintain all trees in a plumb position throughout the warranty period. Straighten all trees including those not guyed. Plants to be straightened shall be excavated and the root ball moved to a plumb position, position, and then re-backfilled. Do not straighten plants by pulling the trunk with guys.

.2

Do not guy trees unless specifically required by the Contract Documents, requested by the City, or in the event that the Contractor request that guying should be permitted as the only alternative way to keep particular trees plumb. .1

The Contractor shall submit a written request for approval by the City to guy any trees not required by the Contract Documents.

.2

Trees that are guyed shall have their guys removed after four months for spring planted trees and after 12 months for summer or fall planted trees or at other times as approved.

.3

Tree guying shall not be permitted as a way to stabilize a tree that is loose in its rootball. All such trees shall be rejected and replaced.

.3

Tree guying, when permitted shall utilize the tree guying materials specified.

.4

Guying material shall be tied to the tree in such a manner as to create a minimum 300mm loop to prevent girdling. Knots shall be a type that does not slip, constricting the trunk. Plants shall stand plumb after guying.

MULCHING .1

Place mulch in the bed to a maximum depth of 50mm such that the entire bed is covered in mulch but mulch does not cover the stem of the plant emerging out of the soil. .1

Utilize Crushed Granite Mulch in tree spaces smaller than 3.5 square meters.

.2

Utilize Bark Mulch in all beds 3.5 square meters or larger.

.2

Ensure soil settlement has been corrected prior to mulching.

.3

Ensure ground is not frozen prior to mulching.


3.11

3.12


PRUNING .1

Prune plants as directed by the City at the time of planting and preserve the natural character of the plant. Pruning shall follow recommendations in “An Illustrated Guide to Pruning, Second Edition” by Ed Gillman.

.2

An arborist certified by the International Society of Arboriculture shall perform all pruning.

.3

Wherever possible and appropriate to the species preserve or create a central leader. Subordinate co-dominant leaders may be tip pruned to suppress lower growth to prepare these leaders for later removal, leaving the single central leader.

.4

Remove and replace excessively pruned or malformed stock resulting from improper pruning.

.5

Pruning shall be done with clean, sharp, rust-free tools. Cuts shall be made flush, leaving no stubs. No tree paint or or sealants shall be used.

.6

Dead wood, suckers, and broken and badly bruised branches shall be removed. Do not prune plant material that has been severely damaged due to transit or handling until viewed by the City.

.7

Pruning of broken or dead branches shall be done after planting, and before acceptance. Pruning procedures shall be reviewed with the City before proceeding. Proceed with pruning in the manner approved by the City.

.8

Form-corrective pruning may occur when tree has become dormant until bud-break in the spring. If corrective pruning dates fall outside the construction schedule, it shall be completed at the next pruning season.

WATERING .1

The Contractor shall be fully responsible to ensure that adequate water is provided to all plants from the point of installation until the date of acceptance. The contractor shall adjust the automatic irrigation system, if available, and shall apply additional water, using hoses as required.

.2

During the initial establishment period, and particularly immediately after installation do not rely on the irrigation system to water the plants. Plants will uptake water only within the root ball and a short distance outside the ball. It is possible to over water the soil while under watering the root ball with the irrigation system.

.3

Hand water root balls of all plants and the soil immediately around the root ball to assure that the root balls have adequate moisture. Test the moisture content in each root ball to determine the water content. Maintain root ball moisture and soil beyond the root ball moisture between 10 and and 20% as measured using a General Digital Moisture Meter. Do not over water the soil around the plants. Use “Tree Gator Bags” to assist in watering watering trees.

WATERING SOIL UNDER THE PAVEMENT .1

Add water into the passive sub-paving watering system to hydrate the Growing Medium within the Growing Medium zones below the pavement. Using a watering watering truck add water until the system pipes begin to refuse to take on more water and back up into the inlet. After 24 hours, repeat the process.

.2

24 hours after the second water application, measure the soil moisture at each soil inspection port. Report the meter readings to the City. If the soil moisture reading is below 10% apply water to those zones a third time until the water backs up into the inlet. Retest the soil moisture and report the readings to the City.


FERTILIZER .1

If any trees leaves are not of a dark green color similar to a vigorous tree of the same species as determined by the City, apply granular fertilizer of liquid fertilizer at rates and times as directed by the City. .1

3.14

3.13

3.14

3.15


Remove a sample of leaves from several of the trees with differing leaf color and send to a foliar testing lab for analysis. Follow the fertilizer recommendations of the foliar test results and as directed by the City.

CLEAN-UP .1

During installation, keep pavements clean and work area in an orderly condition.

.2

Keep the site free of garbage at all times. Immediately dispose of wrappings or waste materials associated with products necessary for the completion of the work.

.3

All garbage shall be kept in a central collection container. Do not bury garbage in backfill.

.4

Once installation is complete, remove any excess soil from pavements or embedded fixtures. Ensure that mulch is confined to planting beds and that all tags and flagging tape are removed from the site. The City’s seals are to remain on each tree.

PROTECTION DURING CONSTRUCTION .1

The Contractor shall protect all work and materials from damage due to planting operations; operations by other Contractors; or trespassers. Maintain protection during installation until acceptance. Treat, repair or replace damaged work work immediately.

.2

Damage done to any of the work by the Contractor, or any of their sub-contractors, shall be replaced by the Contractor at their own expense.

PLANT MAINTENANCE PRIOR TO ACCEPTANCE .1

During the project and prior to Acceptance, the Contractor shall maintain the site, including completed work and existing conditions.

.2

Maintenance during the period prior to Acceptance shall consist of pruning, watering, cultivating, weeding, mulching, removal of dead material, repairing and replacing of tree stakes, tightening and repairing of guys, repairing and replacing of damaged tree trunk protectors, resetting plants to proper grades and upright position, and furnishing and applying such sprays as are necessary to keep plantings free of insects and disease, and in healthy growing condition. Planting areas shall be kept free of trash, weeds, grass, and other undesirable vegetative growth.

.3

Remove all tree guying after the end of the first growing season or as soon as the tree has stabilized. Removal of guying and wrapping is part of the installation work even if that work is required to occur after the date of acceptance.

MAINTENANCE DURING THE WARRANTY PERIOD .1

During the 24-month warrantee period, provide all maintenance for all plantings to keep the plants in a healthy state and the planting areas clean and neat. .1

These maintenance requirements do not apply during any extended warranty period, to any plant, where the City elects to extend the warranty under provisions in Part 1, paragraph “Warrantee” subparagraph .5.


.3


All maintenance work shall be undertaken by trained plant maintenance crews under the supervision of a foreman with a minimum of 5 years experience supervising commercial plant maintenance crews. .1

All chemical and fertilizer applications shall be made by licensed applicators for the type of chemicals chemicals to be used. All work and chemical use use shall comply with all applicable local, provincial and federal requirements.

.2

Assure that hoses and watering equipment and other maintenance equipment does not block paths or be placed in a manner that may create tripping hazards. Use standard safety warning barriers and other procedures to maintain the site in a safe manner for visitors at all times.

.3

All maintenance workers shall wear company uniforms that clearly identifies them as employees of the maintenance company. All workers shall wear required safety equipment and apparel appropriate for the tasks being undertaken.

4.

The contractor shall not store maintenance equipment at the site at times when they are not in use.

5.

Maintenance vehicles shall not park on walks and planting areas at any time.

Provide the following maintenance tasks: .1

Maintenance logs: Maintain a detailed log of all maintenance activities including types of tasks date of task, types and quantities of materials and products used, watering times and amounts, and and number of each crew. Periodically review the logs with the City, and submit a copy of the logs at the end of each year of the maintenance agreement.

.2

Watering; Provide all water required to keep soil within and around the root balls and in the sub paving soil at optimum moisture content for plant growth. .1

Maintain all watering systems and equipment and keep them operational. Monitor soil moisture to provide sufficient water. Check soil moisture and root ball moisture with a soil moisture meter on a regular basis and record moisture readings. Do not over water.

.2

Each year, winterize all watering systems to prevent winter damage and make the system operational in the spring.

.3

Soil nutrient levels: Take a minimum of 6 foliar tissue samples from around the site twice a year in the spring and fall and have them tested by a recognize soil testing lab for chemical composition of plant required nutrients, pH, salt and % organic matter. Test results shall include laboratory recommendations for nutrient applications. Apply fertilizers at rates recommended by the soil test. Use only organic fertilizers with a salt index of 25 or less.

.4

Plant pruning: Prune plants to maintain natural appearance. Review the plantings once a year to evaluate for pruning needs. Remove cross over branching, developing co dominant leaders in trees, dead wood and winterdamaged branches. Do not over prune or shear plants.

.5

Restore plants: Reset any plants that have settled or are leaning as soon as the condition is noticed.


.4


.6

Guying: Remove tree guides and staking after the first full growing season.

.7

Weed control: Hand remove all weeds and any plants that do not appear on the planting plan. Chemical weed control is not permitted. Schedule Weeding shall be as needed but not less than 5 times a year. Schedule weeding days prior to major events as requested by the City.

.8

Trash removal: Remove all trash and debris from all planting beds and maintain the beds in a neat and tidy appearance. The number of trash and debris removal visits shall be no less than 8 times per year. Schedule trash removal days after major events as requested by the City.

.9

Disease and insect control: Provide Integrated plant management (IPM) program to maintain disease and insects at acceptable and manageable levels. Manageable levels shall be defined as minimum damage to plants. Use least invasive methods to control plant disease and insect outbreaks. The City must approve in advance the use of all chemical pesticide applications.

.10

Plant replacement: Replace all plants that are dead or determined by the City to be defective as defined in Part One Paragraph “Warrantee”, as soon as the plant condition is obvious and in suitable weather and season for planting.

.11

Mulch: Refresh any areas of Bark Mulch once a year to maintain complete coverage. Do not over mulch. At no time shall the overall overall mulch thickness thickness be greater that 50mm. Do not apply mulch against against the trunks or or stems of any plants. Replacement mulch shall meet the requirements of the original approved material.

.12

Leaf, fruit and other plant debris removal: Remove fall leaf, spent flowers, fruit and plant part accumulations from beds and paved surfaces. Maintain all surface water drains free of debris. Debris removal shall be undertaken at each visit to weed or pick up trash in beds

Maintenance meetings: Meet with the City a minimum of three times a year to review the progress and discuss any changes that are needed in the maintenance program. At the end of the warrantee period attend a hand over meeting to formally transfer the responsibilities of maintenance to the City or their designated representative. Provide all information on past maintenance activities and provide a list of critical tasks that will be needed over the next 12 months. Provide all maintenance logs and soil test data. Make the contractor’s supervisor available for a minimum of one year after the end of the warrantee period to answer questions about past maintenance.


Appendix Append ix C

Cost Comparison

The cost comparison included in this Appendix has been prepared in order to understand the initial cost of installation for all the different tree planting solutions, including current City standards and the proposed tree planting solutions. The comparison is bas ed on a 10m stretch for all of the planting systems. This allowed the team to get an accurate picture of what each planting system is achieving (cubic meters of soil) in an identical streetscape scenario. It has to be mentioned that for the open planters the 10m length analysis was modified since one planter includes two trees. Therefore for the proposed new planter system, we analysed the whole planter length and the immediate surrounding surface pavement and divided into two. For the existing open planter (T1-A-2c) we assumed the same longitudinal dimensions of the proposed planter (14m, with trees spaced 10m o.c.) and we added the covered tre nch that links other adjacent planters planters to have total length of 20m and then divided the amount in half.

Summary

Soil Volume m³

Total cost per tree

Rate of cost per m³ of soil

8. 8

$5,806

$664

11.6

$6,544

$564

10.5

$7,293

$695

8. 7

$8,195

$942

20.6

$8,692

$422

20.9

$15,190

$727

21.0

$16,699

$795

21.0

$20,890

$995

19.6

$6,339

$323

16.8

$7,166

$427

28.3

$15,501

$548

22.4

$14,772

$659

Current Santdards T1-A-2b (Continuous Soil Trench: Open Planting Bed and Concrete Sidewalk with CIP Trench Cover) T1-A-2c (Continuous Soil Trench: Open Planting Bed and Concrete Sidewalk with CIP Trench Cover) T2-A (Continuous Soil Trench: Raised Planter and Concrete Sidewalk with CIP Trench Cover) T3-A (Continuous Soil Trench: Precast Concrete Planter Cover and Concrete Sidewalk with CIP Trench None of the above hit the 15m3 target

Proposed Drawings Type-1A Cast-in-Place Structural Concrete Panels over Continuous Growing Medium Trench -Design load for Kubota maintenance vehicle Type-1B Precast Structural Concrete Panels & Unit Paving over Continuous Growing Medium Trench -Design load for Kubota maintenance vehicle Type-2 Soil Cells in Continuous Growing Medium Trench with Concrete Paving on Grade -Design load for large semi-truck and trailer Type-2 Soil Cells in Continuous Growing Medium Trench with Unit Paving and Concrete Base on Grade -Design load for large semi-truck and trailer Type-3 Open Planter with Curb Wall Type-3 Open Planter with Seat Wall Type-1A.2 Hybrid Option Cast-in-Place Structural Concrete Panels over Continuous Growing Medium Trench & Soil Cells -Design load for Kubota maintenance vehicle Type-3.2 Hybrid Option Open Planter with Soil Cells

Appendix D

Nashdene Yard Yard Demonstration Project

TREE PLANTING SOLUTIONS IN HARD BOULEVARD SURFACES PILOT PROJECT #1. NASHDENE YARD SILVA CELL UTILITY SERVICING TEST INSTALLATION Specifications Oct. 24, 2011

Silva Cell Utilty Servicing Test Installation Installation Nashdene Yard du Toit Allsopp Hillier Project No.: xxxx Selected Site Demolition

Section 02225 Page 1 October 24, 2011

PART 1 – GENERAL 1.1

General Requirements

.1 1.2

Read and be governed by conditions of the Contract and sections of Division 1. Summary

.1 Removal of all existing paving and various items as shown on the drawings and as indicated in phasing sequence by the Owner. .2 Removal of excess excavated material. 1.3

Protection .1 Protect existing items designated to remain and material designated for salvage or for reuse. In event of damage, immediately replace such items or make repairs to approval of Consultant and at no additional cost to Owner.

1.4

Quality Control .1 Provide a Waste Reduction Work Plan in compliance with Ontario regulations proposing specific measures for reducing, reusing and recycling generated waste.

1.5

Waste Management and Disposal .1 Comply with the requirements of Sections: 01810, and 01742, including, but not limited to, the following: .1 Waste Management and Disposal .1 Comply with the waste management plan developed by the Construction Manager for the Work in accordance with Sections: 01810 and 01742.

PART 2 - PRODUCTS (Not ( Not Applicable) PART 3 - EXECUTION 3.1 .1

Preparation Inspect site and verify with Consultant items designated for removal and items to be preserved.

Silva Cell Utilty Servicing Test Installation Installation Nashdene Yard du Toit Allsopp Hillier Project No.: xxxx Selected Site Demolition 3.2


Removal .1 Remove items indicated. Do not disturb adjacent items designated to remain in place. .2 Square up adjacent surfaces to remain in place by saw cutting or other approved method.

3.3

Salvage .1 Carefully dismantle items containing materials directed or indicated for salvage. Stockpile salvaged materials at locations directed or indicated. .1 Salvage existing traffic and parking signs, parking meters, lighting standards, and emergency call poles for re-installation. .2 Store salvaged items in area designated by Owner. .3 Remove footings and clean posts ready for re-installation. .4 Disconnect and stub off electrical cables.

3.4

Sealing .1 Seal pipe ends and walls of manholes or catch basins where indicated or directed by Consultant. Securely plug to form a watertight seal.

3.5

Disposal of Material

.1 3.6

Dispose of materials off site that are not designated for salvage or re-use in work. Backfill

.1 Backfill in accordance with Section 02316. 3.7

Restoration .1 Upon completion of of work, remove debris, trim surfaces and leave work site clean.

END OF SECTION

Silva Cell Utilty Servicing Test Installation Installation Nashdene Yard du Toit Allsopp Hillier Project No.: xxxx Excavating, Trenching and Backfilling – Site


PART 1 - GENERAL

1.1

General Requirements .1 Read and be governed by conditions of the Contract and sections of of Division 1.

1.2

Definitions .1 Common excavation: excavation of materials of whatever nature, including dense tills, hardpan, frozen materials and partially cemented materials which can be ripped and excavated with heavy hydraulic excavating equipment .2 Waste material: excavated material unsuitable for use in work or surplus to requirements to be disposed off site. .3 Borrow material: Sub-soil material obtained from locations outside area to be graded, and required for construction of fill areas or for other portions of work. This material shall be of residential/agricultural origin and shall meet or exceed the confined fill material criteria as per MOE "Fill Quality Guidelines for Lake Filling in Ontario" of June 1992. Contractor shall provide Consultant with one chemical test per source prior to hauling material to the site. .4 Unsuitable materials: .1 Weak and compressible materials under excavated areas. .2 Frost susceptible materials under excavated areas. .3 Frost susceptible materials: .1 Fine grained soils with with plasticity index less than 10 when tested to ASTM D4318, and gradation within limits specified when tested to ASTM D422 and ASTM C136: Sieve sizes to CAN/CGSB-8.1 .2 Coarse grained soils containing more than 20% by mass passing 0.075 mm Sieve. .5 Unshrinkable Unshrinkabl e fill: very weak weak mixture of of Portland cement, concrete aggregates aggregates and water that resists settlement when placed in utility trenches, and capable of being readily excavated.

1.3

Samples .1 Inform Consultant prior to commencing work of proposed source of fill materials and provide access for sampling.

1.4

Protection of Existing Features .1 Existing buried utilities and structures: .1 Size, depth and location of existing utilities and structures as indicated are for guidance only. Completeness and accuracy are not guaranteed. .2 Prior to commencing excavation work, notify Consultant or authorities having jurisdiction, establish establish location location and and state of of use of buried utilities utilities and structures. structures.



Consultant or authorities having jurisdiction shall clearly mark such locations to prevent disturbance during work. .3 Confirm locations of buried utilities by careful test excavations. .4 Maintain and protect from damage, damage, water, sewer, gas, electric, telephone and other utilities and structures encountered. Obtain direction of Consultant before moving or otherwise disturbing utilities or structures. .5 Record location of maintained, re-routed and abandoned underground lines. PART 2 - PRODUCTS 2.1

Materials .1 Aggregates, General: to Section 02701 and OPSS 1010. .2 Granular Bases: to Section 02721 and OPSS 1010. .3 Fill concrete: .1 Minimum compressive strength at 28 days: 15 MPa. .2 Maximum slump at time and point of discharge: 100 mm. .4 Unshrinkable fill: .1 Maximum compression strength at 28 days: 0.4 Mpa. .2 Maximum cement content: 25 kg/m3 of concrete mix. .3 Slump at time and point of discharge: 150 to 200 mm. .4 Air content: 4 to 6% .5 Sand bedding: to Section 02701 and following requirements: .1 Natural sand consisting of hard, strong, durable particles, free from a coating of any injurious material and free from injurious amounts of other deleterious materials. .2 Gradations to be within within limits specified when tested to ASTM C136-84a. Sieve sizes as shown: Sieve Designation % Passing 4.75 mm 100 2.36 mm 95-100 1.18 mm 60-100 0.600mm 35-80 0.300 mm 15 - 50 0.150 mm 2-15 0.075 mm 0-5 .5 Native Backfill: selected site material from excavation approved by Consultant for use intended, unfrozen and free from rocks larger than 150 mm, cinders, ashes, sods, refuse or other deleterious materials. .6 Borrow material: See Part 1 - General, Definitions.


Site Preparation



.1 Remove obstructions, ice and snow, from surfaces to be excavated within limits indicated. .2 Cut pavement or sidewalk neatly along limits of proposed excavation in order that surface may break evenly and cleanly. 3.2

Stockpiling .1 Stockpile fill materials in areas designated by Consultant. Stockpile granular materials in manner to prevent segregation. .2 Protect fill materials materials from from contamination contamination..

3.3

Dewatering .1 Keep excavations free of water while work is in progress. .2 Protect open excavations against flooding and damage due to surface run-off. .3 Dispose of water in a manner not detrimental detrimental to public and private property, or any portion of work completed or under construction. .4 Continuously dewater the excavations to control surface runoff or perched water table seepage for concreting and other work to be carried out in the dry condition. .5 Submit for Consultant's review details of proposed dewatering methods, such as dikes or well points. .6 Disposal of discharge water water shall conform with with requirements of the City Sewer Sewer Use Bylaw. .7 Dewatering operations shall be in conformance with MOE Permit to Take Water requirements. Contractor is responsible for procurement of permits.

3.4

Excavation .1 Excavate to lines, grades, locations, elevations and dimensions as indicated or directed by Consultant. .2 Remove excavated material and other obstructions obstructions encountered during excavation. .3 Excavation must not interfere with normal 45 deg. splay of bearing from bottom of any footing. .4 Do not disturb soil within branch spread of trees or shrubs that are to remain. If excavating through roots, excavate by hand and cut roots with sharp axe or saw. .5 For trench excavation, unless otherwise authorized by Consultant in writing, do not excavate more than 10m of trench in advance of installation operations and do not leave open more than 5 m at end of day's operation.



.6 Dispose of surplus and unsuitable excavated material in approved off-site location. .7 Do not obstruct flow of surface drainage or natural watercourses. .8 Earth bottoms of excavations to be undisturbed soil, level, free from loose, soft or organic matter. .9 Notify consultant when bottom of of excavation excavation is reached. .10 Obtain Consultant approval of completed excavation. .11 Remove unsuitable material from trench bottom to extent and depth as directed by Consultant. .12 Correct unauthorized over-excavation as follows: .1 Fill under bearing surfaces and footings with concrete specified for footings. .2 Fill under other areas with Granular 'B' material specified in Section 02721. .13 Hand trim, make firm and remove loose material and debris from excavations. Where material at bottom of excavation is disturbed, compact foundation soil to density at least equal to undisturbed soil. Clean out rock seams and fill with concrete mortar or grout to approval of Consultant. 3.5

Excavation, Hauling and Disposal of Non-hazardous Non-hazardou s Waste .1 The Owner will retain a soils consultant to monitor the excavation of the impacted soils to assess disposal options. .2 Excavated sub-grade materials having a hydrocarbon odour or excavated road base materials exceeding the Table B criteria of MOEE "Guidelines for use at Contaminated Sites in Ontario" (February, 1997), cannot be re-used on-site. Instead, it shall be disposed of at a municipal landfill site (i.e., sanitary landfill) licensed to accept such waste. Carriers disposing the waste shall be registered with the MOEE. .3 Disposal as lakefill is not permitted.

3.6

Bedding and Surround of Underground Services .1 Place and compact granular material for bedding and surround of underground underground services as indicated and as specified. .2 Place bedding and and surround material in unfrozen condition.

3.7

Backfilling .1 Do not proceed with backfilling backfilli ng operations until Consultant has inspected and approved installation. .2 Areas to be backfilled to be free from debris, snow, ice, water and frozen ground.



.3 Do not use backfill material which which is frozen or contains ice, snow or debris. Unless otherwise specified, backfill to consist of approved native backfill. Refer to drawings for additional requirements. .4 Place backfill material in uniform layers not exceeding 150 mm compacted thickness up to grades indicated. Compact each layer before placing succeeding layer. .5 Backfill around installations. .1 Place bedding and surround material as specified elsewhere. .2 Do not backfill around or over cast-in-place concrete within 24 hr. after placing of concrete. .3 Place layers simultaneously on both sides of installed work to equalize loading. Difference not to exceed 0.3 m. .4 Where temporary unbalanced earth pressures are liable to develop on walls or other structures: .1 Permit concrete to cure for minimum 14 days or until it has sufficient strength to withstand earth and compaction pressure and approval obtained from Consultant or; .2 If approved by Consultant, erect bracing or or shoring to counteract unbalance, and leave in place until removal is approved by Consultant. 3.8

Inspection and Testing .1 Testing of materials and compaction will be carried out by testing laboratory designated by Owner. Frequency of tests will be determined by Consultant. .2 Owner will will pay costs for inspection and testing.

3.9

Restoration .1 Upon completion of work, remove waste materials and debris, trim slopes, and correct defects as directed by Consultant. .2 Clean and prepare new work areas as directed by Consultant. .3 Clean and reinstate areas affected affected by work as directed by Consultant.

END OF SECTION

Silva Cell Utilty Servicing Test Installation Installation Nashdene Yard du Toit Allsopp Hillier Project No.: xxxx Aggregates: Aggregates: General General


PART 1 - GENERAL 1.1 .1 1.2

General Instructions Instructi ons Read and be governed by Conditions of the Contract and Sections of Division 1. References

.1

ASTM C 117-90, Test Method for Material Finer Than 0.075 mm Sieve in Mineral Aggregates Aggregates by Washing.

.2

ASTM C 131-89, Test method for Resistance to Degradation of Small-Size Coarse aggregate by Abrasion and Impact in the Los Angeles Machine.

.3

ASTM C 136-92, Method Method for Sieve Analysis of Fine and Coarse Aggregates. Aggregates.

.4

ASTM D 698-91, Test Method for Laboratory Compaction Compaction Characteristics of of Soil Using Standard Effort (12,400 ft-1bf/ft3) (600 kN-mlm).

.5

CAN/CGSB-8.1-88, CAN/CGSB-8.1- 88, Sieves Testing, Woven Wire, Inch Series.

.6

CAN/CGSB-8.2-M88, CAN/CGSB-8.2- M88, Sieves Testing, Woven Wire, Metric.

1.3 .1

Delivery, Storage and Handling Store cement in weather weather tight bins or silos that provide provide protection from dampness and easy access for inspection and identification of each.


Materials

.1

Fine aggregates satisfying requirements of applicable section shall be one, or a blend of of following: .1 natural sand .2 manufactured sand .3 screenings produced in crushing of of quarried rock, boulders, gravel or slag.

.2

Course aggregates satisfying requirements of of applicable section shall be one, or a blend of following: .1 crushed rock from an approved bedrock source. .2 gravel composed of of naturally formed particles of stone from an approved source.

.3

Granular base material: 19 mm crusher run limestone, or Granular ‘A’.

.4

Granular sub-base material: 50 mm crusher run limestone, or Granular ‘B’.

Silva Cell Utilty Servicing Test Installation Installation Nashdene Yard du Toit Allsopp Hillier Project No.: xxxx Aggregates: Aggregates: General General .5


Crushed pit-run or screened stone, gravel or sand consisting of hard, durable, durable, angular particles, free from clay lumps, cementation, organic material, frozen material and other deleterious materials.


Sequence of Operation

.1

Place granular base after finished sub-base surface or subgrade is inspected and approved by Consultant.

.2

Placing .1 Construct granular base base to depth and grade in areas indicated. .2 Ensure no frozen material is placed. .3 Place material only on clean unfrozen unfrozen surface, free from snow and ice. .4 Place material using methods which do not lead to segregation or degradation of of aggregate. .5 Place material to full width in uniform layers not exceeding 150 mm compacted thickness. .6 Shape each layer to smooth contour and compact to specified density before succeeding layer is placed. .7 Remove and replace that portion of layer in which material becomes segregated during spreading.

.3

Compaction Equipment .1 Compaction equipment equipment to be capable of obtaining required material densities. .2 Efficiency of equipment not specified to be proved proved at least as efficient as specified equipment at no extra cost and written approval must be received from Consultant before use. .3 Equipped with with device that records hours of actual work, not motor running hours.

.4

Compacting in accordance with ASTM D 698 and ASTM D 1557. .1 Compaction of Road Pavement Base: Compact to density of not less than 100% SPMDD. .2 Compaction of Sidewalks Base: Compact to density of of not less than 100% of SPMDD. .3 Shape and roll alternately to obtain smooth, even and uniformly compacted base. .4 Apply water as necessary during compacting to obtain specified density. density. .5 In areas not accessible to rolling equipment, equipment, compact to specified density with mechanical tampers approved by Consultant. .6 Correct surface irregularities irregulari ties by loosening and adding or removing material until surface is within specified tolerance.

3.2

Site Tolerances .1 Finished base surface to be within plus or minus 10 mm of established grade and cross section but not uniformly high or low.

3.3

Proof Rolling

Silva Cell Utilty Servicing Test Installation Installation Nashdene Yard du Toit Allsopp Hillier Project No.: xxxx Aggregates: Aggregates: General General


.1

For proof rolling use roller of 45400 kg gross mass with with four pneumatic tires each carrying 11350 kg and inflated to 620 kPa. Four tires arranged abreast with centre to centre spacing of 915 mm maximum.

.2

Consultant may authorize use of other acceptable proof rolling equipment.

.3

Proofroll top of base upon completion of of fine grading and compaction.

.4

Make sufficient sufficient passes with proof roller to subject every point on surface to three separate passes of loaded tire.

.5

Where proof rolling reveals defective areas: .1 Remove base, sub-base and subgrade material to depth and extent directed by Consultant. .2 Backfill excavated subgrade with sub-base material and compact in accordance with Section 02316. .3 Replace sub-base material and compact in accordance with with Sections 02316 02316 and 02721. .4 Replace base material and compact in accordance with this Section.

3.4

Inspection and Testing

.1

Testing of materials and compaction will be carried out by testing laboratory designated by Owner. Frequency of tests will be determined by Consultant.

.2

Owner will pay costs for inspection and testing.

3.5 .1

Protection Maintain finished base in condition conforming to this section until succeeding material is applied or until acceptance by Consultant.

END OF SECTION

Silva Cell Utilty Servicing Test Installation Nashdene Yard du Toit Allsopp Hillier Project No.: xxxx Concrete Formwork - Site




.1 1.2

Read and be governed by conditions of the Contract and sections of Division 1. Reference Standards

.1 Do concrete formwork in accordance with CAN3-A23.1, except where specified otherwise. .2 Do falsework in accordance accordance with CSA S269.1-1975, S269.1-1975, except where specified otherwise. PART 2 - PRODUCTS 2.1

Materials

.1 Formwork lumber: plywood and wood formwork materials to CAN3-A23.1. .2 Falsework materials: to CSA S269.1. .3 Form release agent: chemically active release agents containing compounds that react with free lime present in concrete to provide water insoluble soaps, preventing concrete from sticking to forms. .4 Form stripping agent: colourless mineral oil, free of kerosene, with with viscosity between 70 to 110mm/s at 40/o.C, flash point minimum 150/o.C. .5 Form ties: removable or snap-off metal ties, fixed or adjustable length, free of devices leaving holes larger than 25mm diameter in concrete surface. .6 Form liner: Waferboard: to CAN 3-0188.2, P1 grade, 6mm thick PART 3 - EXECUTION 3.1

Erection

.1 Verify lines, levels and centres before proceeding proceeding with formwork and ensure dimensions agree with drawings. .2 Construct forms to produce finished concrete conforming to shape, dimensions, locations and levels indicated within tolerances required by CAN 3-A23.1. .3 Line forms or provide suitable forms to provide smooth (fair face) finish for the following surfaces with material only as approved by Project Manager. .1 Exposed vertical faces of curbs, stairs and fascias. .4 Construct falsework in accordance with CSA S269.1.

Silva Cell Utilty Servicing Test Installation Nashdene Yard du Toit Allsopp Hillier Project No.: xxxx Concrete Formwork - Site .5 Align form joints and make watertight. Keep form joints to minimum.


.6 Use 25mm chamfer chamfer strips on external corners of curbs and fascia panels where indicated on drawings. .7 Form chases,slots,openings, chases,slots,openings,drips,recesses, drips,recesses, expansion and control joints as indicated. .8 Clean form work in accordance with CAN3-A23.1 before placing concrete. .9 Leave formwork in place for a minimum period of one day after placing concrete. .10 Re-use of formwork and falsework subject to requirements of CAN3-A23.1. .11 Forms must be coated with a release agent before each use.

END OF SECTION

Silva Cell Utilty Servicing Test Installation Nashdene Yard du Toit Allsopp Hillier Project No.: xxxx Cast-In-Place Concrete - Site




.1 1.2

Read and be governed by conditions of the Contract and sections of Division 1. Referenced Standards

.1 Do cast-in-place concrete work work in accordance with CSA CAN3-A23.1 and supplements and testing in accordance with CSA CAN3-A23.2 and supplements, except where specified otherwise. 1.3

Quality Assurance .1 Submit proposed quality control procedures for Consultant’s approval including, but not limited to, proposed methods of concrete protection during hot or cold weather conditions. .2 The Contractor must have have a minimum of 5 years experience in concrete work. .3 All materials must conform to CAN3-A23.1, latest edition. A copy must be kept on-site at all times during construction. .4 Furnish the Consultant with a certificate prepared by the ready-mix concrete suppliers stating that all requirements regarding strength, slump, air entrainment, mix, materials and ratio have been met and maintained. .5 Prior to pouring concrete obtain the approval of the Consultant of all formwork, placement of reinforcing steel, consolidation of subgrade and placement and consolidation of granular base. .6 Ensure work complies with the Ontario Building Code and all pertinent local by-laws and regulations. These shall govern in case of conflict with the specifications. specifications . Obtain and pay for all necessary permits before starting work. .7 Consultant shall have authority to reject or call for improvements in workmanship where he considers that concrete work falls below acceptable standard. Contractor shall be given one day notice that all concreting shall cease unless such improvements are made.

1.4

Samples and Mock-Ups .1 Contractor to provide a sample mock-up for approval of all concrete work (paving, walls, steps) per the detail shown on the drawings. The mock-up will show the sizes and final installation relationships between the various adjacent materials, and the finishes as specified. .2 The approved mock-up shall establish the standard by which all work shall be assessed. Work that fails to meet the standard set by the mock-up shall be replaced. .3 Mock-up shall not be incorporated into the work, and shall be protected for the duration of the contract.



.4 Contractor to provide provide (3x) 1.0m 1.0m x 2.0m panels for approval by Consultant prior prior to installation of sidewalks. PART 2 - PRODUCT STANDARDS 2.1

Materials .1 Portland cements: to CSA CAN3-A5. .2 Water, fine aggregates, normal weight coarse aggregates: aggregates: to CSA CAN3-A23.1. .3 Air entraining admixture: TO CSA CAN3-A266.2. .4 Chemical admixtures: to CSA CAN3-A266.2. .5 Pozzolanic mineral admixtures: to CSA CAN3-A23.5. .6 Non-shrink grout: premixed compound consisting of non-metallic aggregate, cement, water reducing and plasticizing agents, of pouring consistency, capable of developing compressive strength of 50 MPa at 28 days. .7 Dry Pack: Pack: premixed or non-premixed composition of non-metallic aggregate, cement and sufficient water for the mixture to retain its shape when made into a ball by hand and capable of developing compression strength of 50 MPa at 28 days. .8 Premoulded joint fillers: .1 Bituminous impregnated fibreboard: to ASTM D1751. .9 Curing Blanket: UltraCure Sun, manufactured by McTech Group Inc., and distributed by Geroquip Inc., Laval, Quebec, tel: 450.978.0200.

2.2

Admixtures .1 Obtain approval of Consultant before using admixtures. admixtures. .2 Use only compatible admixtures. .3 Use of calcium chloride not permitted.

2.3

Air Entraining .1 Comply with CSA CAN3-A23.1 for use of air entrainment.

2.4

Concretes Mixes .1 Proportion normal density concrete to CSA CAN3-A23.1. .2 Type of cement: Symbol 10.



.3 All concrete subject to freeze/thaw cycles including perimeter foundation walls, shall be exposure Class C. All other interior concrete exposure Class D. .4 Maximum size of coarse aggregate 20 20 mm. .5 For maximum and minimum slumps see CSA CAN3-A23.1. PART 3 - EXECUTION 3.1

General .1 Refer to Sections 02710 for Concrete Formwork, and Section 02720 for Concrete Reinforcement. .1 Obtain Consultant's review before placing concrete. .2 Place concrete in accordance with CSA CAN3-A23.1. .3 Ensure reinforcement and and inserts are not disturbed during concrete placement. .4 Obtain Consultant's review of proposed method of protection of concrete during placing and and curing in adverse weather prior to placing of concrete. .5 Maintain accurate record of poured concrete items to indicate date, location of pour, quality, air temperature and test samples taken. .6 Use internal vibrators whenever practicable for consolidating concrete. .7 Set forms true to line and grade, join neatly and tightly, and stake securely to resist concrete pressure and impact from tampers without springing. All alignment and grade of formwork shall be correct within 3mm in a 3.0m span.

3.2

Installation .1 Ensure that subgrade of compacted fill conforms to elevations and sections before placing granular base material. .2 Place granular base base to minimum 150mm (6”) compacted thickness and compacted to 98% Standard Proctor density to ASTM D698-00a. .3 Screed concrete to required levels, to tolerance of 12.7 mm (1/2”) in 3050mm (10’). .4 Provide saw cut control joints as indicated on Drawings. Incorrect saw cuts in concrete will result in the removal and re-installation re-installatio n of the concrete panel. If no control joints indicated, maximum spacing to be 1.6m o/c. .5 Provide expansion joints as shown on Drawings and between road curbs, planter curb and sidewalk as well as adjacent to all structures, buildings, columns, walls, light poles and existing hard surfaces. Incorrect expansion joints in concrete will result in the removal and re-installation of the concrete panel or curb/ wall Expansion joint filler to be recessed 5mm below finish grade of concrete unless otherwise indicated on drawings. Expansion joints in walls to be caulked per detail drawings.



.6 Locate keyed joints as shown on drawings and details. .7 While placing concrete, compact thoroughly and uniformly by approved means to ensure a dense homogeneous structure free of air pockets, and honeycombs and closely bonded with reinforcement. .8 No offsets will be allowed between adjacent sections of joint fillers and no plugs of concrete will be permitted anywhere within an expansion joint. .9 Use joint filler to separate slabs on grade from vertical surfaces or structures. 3.3

Inserts .1 Set sleeves, ties, anchor bolts and other inserts, openings and sleeves, in concrete floors and walls, as required by other trades. Sleeves, openings, etc., not indicated on structural drawings must be approved by the Consultant. .2 No sleeves ducts, pipes or other other openings shall pass through beams or piers, except where detailed on structural drawings or approved by the Consultant. .3 Check locations and sizes of sleeves, openings, etc., with architectural, mechanical and electrical drawings.

3.4

Defective Concrete .1 Remove and replace excessive honeycomb or embedded debris in concrete as directed by the Consultant.

3.5

Joint Fillers .1 Locate and form isolation and expansion joints as indicated. Install joint filler. .2 Use 12 mm thick joint filler to separate slabs-on-grade from vertical surfaces and extend joint joint filler filler from bottom bottom of slab slab to withi within n 12 mm of of finish finished ed slab slab surface surface unless unless indic indicate ated d otherwise.

3.6

Finishing .1 Finish concrete in accordance with with CSA CAN3-A23.1. .2 Unless otherwise indicated on on drawings, finish all site concrete walls and curbs with medium sandblast finish; all concrete paving with medium broom finish. All to Consultants approval. .3 Sandblast finish shall expose a range of small and medium sized aggregates frequently and evenly throughout all finished concrete. Allow minimum of one week’s approval time between completion of sample and commencement of work. .4 Adhere to approved mock-up for all concrete finishes.



.5 All sidewalk finishing to be completed prior to freeze-up. Fence off off sidewalks to prevent use by pedestrians, at contractors expense. .6 Rub exposed sharp edges of concrete with carborundum to produce 3 mm radiused edges unless otherwise detailed. .7 Apply curing blanket to manufacture’s specifications. .8 For typical cast-in-place cast-in- place concrete paving. .1 Sawcut control joints; tooled radius on expansion joints; no margins .2 Tool edges prior to sandblast finish to remove margins. .3 Apply smooth wood float finish before final finish .9 For typical cast-in-place concrete walls / curbs: .1 Sawcut control joints; tooled radius on expansion joints; no margins .2 Apply smooth wood float finish before final finish 3.7

Field Quality Control .1 Concrete materials and methods of construction: to CSA-A23.1 and testing in accordance with CSA-A23.2-94 unless otherwise specified. .2 Inspection and testing of concrete and concrete materials will be carried out by a testing laboratory designated by the Consultant. .3 Testing laboratory will take three (3) test cylinders for each test. Submit test cylinders to designated laboratory. The frequency of the test will be in accordance with CSA CAN3 A23.2.94 A23.2.94.. .4 Testing laboratory will take one additional test cylinder during cold weather concreting. Cure cylinder on job site under same conditions as concrete it represents. .5 Testing laboratory will make at least one slump test for each set of of test cylinders taken. .6 Inspection and testing by Consultants will not augment or replace Contractor quality control nor relieve him of his contractual responsibilities. .7 Cost of inspection and testing shall be paid in accordance with Section Section 01000.

3.8

Review of Construction .1 Review of construction by the Consultant and and inspection and testing by an independent Inspection and Testing Agency, is to ascertain general conformity with contract documents. It does not relieve the Contractor of his contractual responsibilities. The review is based on representative samples of the work and does not relieve the Contractor from carrying out his own quality control and making the work inconformity with the drawings and specifications.


3.4


Clean-up .1 Clear away excess and waste materials and debris resulting from the work of this section. .2 As late as possible prior to turning the building over to the Owner, clean down down concrete to remove surface discolorations, discolorat ions, efflorescence and the like. Use a suitable cleaning agent which will not itself stain the surfaces or mar the texture through chemical reaction.

END OF SECTION

Silva Cell Utilty Servicing Test Installation Nashdene Yard du Toit Allsopp Hillier Project No.: xxxx

Section 02785 Page 1 October 24, 2011 Unit Paving



.1 1.2

Read and be governed by conditions of the Contract and sections of Division 1. Description

.1 Work of this section consists of design, labour, materials, tools and equipment, to supply and install the following work as indicated, specified herein, and required for a complete and proper installation. .1 Unit pavers .2 Complete layout details details for the installation of the above with supervision and checking, as required to ensure that the installation is correct. 1.3

Qualifications .1 Work shall be executed only by a company with proven experience in the design and manufacture of architectural precast concrete and having adequate finances, equipment, plant and skilled personnel to expeditiously detail, fabricate and install the work of this section as required by the Contract Documents. .2 Manufacturer shall be responsible for the design, connections and installation of the precast concrete units and shall direct the placing of items to be cast in concrete work. .3 Manufacturer shall be qualified in accordance with CSA A23.4-00/A251A23.4-00/A251-00 00 Qualification Qualificat ion Code for Manufacturers of Architectural and Structural Precast Concrete.

1.4

Quality Assurance .1 All unit paving work shall be carried out by an approved contractor having at least 5 years experience in the work similar to that specified here. .2 Before commencing work, visit site and become familiar with the specifications governing the work of others, particularly drainage, backfill, concrete, mechanical and electrical work. .3 Commencement of work will denote acceptance of sub-surfaces and conditions. Subsequent failure of installed work of this section due to sub-surface defects will be rectified at no cost to the Owner.

1.5

Finish, Samples, and Mock-ups .1 Construct a 2.0M x 3.0M area of unit paving illustrating the various patterns as shown on the drawings. .2 No blotching, patchiness or shade difference will be accepted. .3 Submit 2 samples of each unit paver for approval by Consultant.



1.6

Handling, Storage and Protection .1 Store unit pavers off the ground to prevent contamination, staining, or other defects. .2 Cover sand with waterproof waterproof covering to prevent exposure exposure to weather. Weigh down covering to prevent removal by wind. .3 Store different types of aggregates separately.

1.7

Warranty .1 Provide standard CPCI Ontario Chapter warranty of 2 years for unit paving work in accordance with Section 01780.


Unit Pavers .1 Precast pavers: __________________ Supply samples to Consultant for approval. .2 Granular Base for concrete unit pavers: Granular Base ‘A’ as per Section 02701. .3 Sand Setting Bed: Concrete Sand conforming to CSA A23.1. A23.1. gradation for fine aggregate. .4 Joint Filler: _____________


Allowable Tolerances .1 Finish paving surfaces within 6mm of established elevations and 3mm of other surfaces at joints between other paving types, manholes and other features within paved areas; and within 3mm under a 3.0M long straightedge.

3.2

Site Conditions .1 Carry out work of this section only when surfaces are at least 2°C and the temperature is rising, or: .2 Carry out the work of this section involving mortar and grout only when temperature is at or above that recommended by manufacturer. .3 Suspend paving operations when temperature falls below specified minimum.

3.3

Excavation and Backfilling: .1 As per Section 02316.

3.4

Layout and Installation Installatio n of Unit Paving .1 Install unit paving true to grade, in location, layout and pattern as indicated on detail



drawings. .2 Stake layout of unit paving for Consultant to approve prior to commencing installation. installati on. .3 Ensure granular base and sand setting bed is dry (4-8% moisture content) prior to placement of unit pavers. .4 Place compacted Granular ‘A’ to thickness as indicated on detail drawings. .5 Place sand to compacted thickness as indicated on detail drawings. .6 Pavers are to be laid in pattern as detailed. All joints to be offset. Smaller pavers are to be used on tighter radii or where cutting is required. .7 Install pavers with tight butt joints. .8 Tamp down and level pavers with mechanical plate vibrator as recommended by the manufacturer until pavers are true to grade and free of movement. .9 Fill spaces between pavers pavers by sweeping in sand joint filler. .10 Pass mechanical plate vibrator on sand cushion over surface course to achieve compaction of sand in joints. .11 Surface of finished pavement: free from depressions exceeding 3mm as measured with 3.0m straight edge. .12 Install edge restraint where pavers meet soft surfaces, per manufacturer’s specifications. .13 Where required, cut paving units accurately with a concrete saw. A guillotine shall not be used. Do not damage edges or exposed surfaces. Treat cut edges to match factory condition. .14 Chipped, blemished or defective units shall not be installed. .15 Ensure that all grade transition zones are made gently and smoothly. .16 Clean surfaces of unit paver and maintain free of abrasive and staining substances. .17 All work within 1 m of the laying face must be left fully compacted with sand-filled joints at the completion of each day. 3.5

Adjustment and Replacement .1 At time of final acceptance at Project completion, and again again at termination terminati on of of guarantee period, Work of this Section will be inspected by Consultant, and adjustments and replacements shall be made under Work of this Section. .2 The warranty period begins begins after receipt of of written acceptance of work of this Section by the Consultant. .3 Adjustment and replacement work shall be performed performed as specified in this Section with materials of same size, variety and quality of material replaced. .4 Replacement work shall be done under an additional guarantee of the same length and



conditions as described in this Specification. It shall date from time of Consultant’s approval of replacement work. 3.6

Clean-up .1 Remove, as work progresses, excess or foreign materials that would set on or become difficult to remove fr om finished surface. .2 At completion, clean exposed surfaces of precast units. Remove dirt and other extraneous matter. Do not use acidic cleaners.

END OF SECTION

INSTALLATION SPECIFICATIONS FOR INTERLOCKING CONCRETE PAVEMENTS

Applicable to Standard, Textured & Heavy Duty Unit Pavers

1-800-UNILOCK

www.unilock.com

Installation Specifications for Interlocking Concrete Pavements

FOREWORD These outline specifications have been prepared for the general guidance of specifiers, engineers, contractor and superintendents associated with the construction of interlocking concrete pavements in any type of traffic applications. A qualified engineer must determine the suitability of the design, confirm site conditions and monitor the installation in more critical applications.

INTRODUCTION ®

Unilock pavers are manufactured in a variety of shapes, colors and textures for residential, commercial, municipal and industrial applications. They offer Engineers, Architects, Architects, Landscape Architects Architects and Planners Planners several several engineered engineered placing systems systems that are durable, economical and aesthetically attractive. The systems also lend themselves to a multitude of design applications. ®

Unilock pavers are manufactured to tight dimensional tolerances. This, in combination with their interlocking capabilities, allows the surface to act as a total membrane with a high resistance to compressive loads and lateral forces. ®

Advantages of Unilock pavers: •

®

The design and performance performan ce advantages of Unilock pavers over other surfaces are dramatically reflected in the wide range of colors, individual shapes, texture, and variety of installation patterns. ®

Unilock pavers offer an economical alternative to other types of pavements when viewed in the long term where maintenance and replacement costs are considered. In some cases, initial costs can be even lower.

•

•

•

•

•

•

•

Ability to tolerate some subgrade and/or aggregate aggregate base deflection while still maintaining pavement continuity and structural integrity. Ease of access to underground services and utilities and subsequent replacement without visual or structural changes. High compressive strength provides excellent surface durability. Low water absorption rate helps to resist potential damage caused by fuel and oil leakage, salt scaling, and freeze-thaw cycles. Superior skid resistance for both vehicular and pedestrian applications. application s. Simplicity of construction methods generally suited to unskilled labor, which can reduce installation costs.

•

Very low maintenance maintenan ce requirements. requirement s.

•

Maximum efficiency efficie ncy is obtained when when the pavers are installed mechanically.

Unilock Specifications

Page 2


INSTALLATION INSTALLATION SPECIFICATIONS SPECIFICATIONS FOR________________________ FOR__________ ________________ __ SECTION 0278 INTERLOCKING CONCRETE PAVERS PART 1

GENERAL

1.1

SECTION INCLUDES

A.

Concrete pavers pavers

B.

Bedding and joint sand.

C.

Aggregate Base

D.

Edge Restraints

1.2

RELATED SECTIONS

Note: Note: These related sections refer to standard specifications available from the local municipality or highway agency or from major specification writing agencies such as the Federal Highway Administration (FHWA), the National Stone Association (NSA), the American Concrete Pavement Association (ACPA), the National Asphalt Producers Association (NAPA), the National Institute of Building Sciences (NIBS), National Master Specifications (NMS), the American Society for Testing and Materials (ASTM), the Canadian Government Standards Board (CGSB), the Ontario Provincial Standard Specifications (OPSS), etc. A. Section: [ - ] - Curbs and and Drains. B. Section: [ - ] - Aggregate Base. C. Section: [ - ] - Cement Treated Base. D. Section: [ - ] - Asphalt Treated Base. E. Section: [ - ] - Overlays of Asphalt and Concrete Pavements. F. Section: [ - ] - Roofing Materials. G. Section: [ - ] - Bitumen and Neoprene Setting Bed, Acrylic Fortified Mortar Setting Bed. H. Section: [ - ] - Geotextiles. I. Section: [ - ] - Unshrinkable Fill 1.3

REFERENCES

Note: Note: Street, industrial, port and airport pavement thicknesses should be designed in consultation with a qualified civil engineer, in accordance with established flexible pavement design procedures, LOCKPAVE software, and in accordance with Concrete Paver Industry Technical Bulletins. Sample construction detail ® drawings are available from Unilock . This specification may require modification for pavements with non-stabilized aggregate bases, asphalt or cement stabilized bases, or asphalt and concrete bases.


Page 3


A.

American Society Society of Testing Testing and Materials Materials (ASTM) (latest edition): edition): 1. C 33 Specification Specificat ion for Concrete Aggregates. Aggregates. 2. C 136 Method for Sieve Analysis for Fine and Coarse Aggregate. 3. C 140 Sampling and Testing Concrete Masonry Units. 4. C 144 Standard Standard Specifications Specifications for Aggregate Aggregate for Masonry Mortar. 5. C 936 Specifications for Solid Interlocking Concrete Paving Units. 6. C 979 Specification for Pigments for Integrally Colored Concrete. 7. D 698 Test Methods for Moisture Density Relations of Soil and Soil Aggregate Aggregate Mixtures Using a 5.5 lb (24.4 N) Rammer and 12 in. (305 mm) drop. 8. D 1557 Test Methods for Moisture Density Relations of Soil and Soil Aggregate Aggregate Mixtures Using a 10-lb (44.5 N) Rammer and 18 in. (457 mm) drop. 9. D 2940 Graded Aggregate Material for Bases or Subbases for Highways or Airports. Note: In order to determine the latest version of the listed specifications and standards, please consult the ASTM web page (www.astm.com) 1.4

QUALITY ASSURANCE

A.

Installation shall shall be by a contractor contractor and crew with with at least one year year of experience experience in placing interlocking concrete pavers on projects of similar nature or dollar cost.

B.

The Contractor shall conform to all local, state/provincial state/provinc ial licensing and bonding requirements.

1.5

SUBMITTALS

A.

Shop or product product drawings drawings and product product data shall shall be submitted. submitted.

B.

Full size samples of concrete paving units shall be submitted to indicate Color and shape selections. Color will be selected by Architect/Engineer/Landscape Architect/Owner Architect/Owner from Unilock's Unilock's available available colors. colors.

C.

Sieve analyses for grading of bedding and joint sand shall be submitted. submitted .

D.

Test results shall be submitted from an independent testing laboratory for compliance of paving unit requirements to ASTM C 936 or other applicable requirements.

E.

The layout, pattern, and relationship of paving joints to fixtures and project formed details shall be indicated.

Note: The pattern patte rn in which pavers are a re installed is very important in vehicular veh icular applications. Avoid patterns with long continuous lines; these may be subject to failure under vehicular traffic. 1.6

MOCK-UPS

A.

A 7 ft. x 7 ft. (2m x 2m) paver area shall be be installed as as described described in Article 3.02.

B.

This area will be used to determine the amount that the pavers settle into


Page 4


bedding sand after compaction, joint sizes, lines, laying pattern(s), color(s), and texture of the project. C.

This area shall be the standard from which the work will be judged.

1.7

DELIVERY, STORAGE, AND HANDLING

A.

Concrete pavers pavers shall be delivered to the site in steel banded, plastic banded, or plastic wrapped cubes capable of transfer by fork lift or clamp lift. The pavers shall be unloaded at the job site in such a manner that no damage occurs to the product.

B.

Bedding and joint sand shall be covered with a secure waterproof covering to prevent exposure to rainfall or removal by wind.

C.

Delivery and paving schedules shall be coordinated in order to minimize interference with normal use of buildings adjacent to paving.

1.8

ENVIRONMENTAL CONDITIONS

A.

Do not install install sand or pavers pavers during during heavy rain or snowfall. snowfall.

B.

Do not install sand and pavers over frozen base materials.

C.

Do not install frozen sand.

PART 2

MATERIALS

2.1

CONCRETE PAVERS

A.

Supplied by: by: ®

Unilock Location (Address, Phone, Fax) B.

Product name(s)/shape(s), name(s)/shap e(s), color(s), overall dimensions, and thickness of the paver(s) specified as follows: Product name:

_______________ _______________

Product shape(s):

_______________ ___________ ____

Product color(s),

_______________ ___________ ____

Note: Note: Concrete pavers may have spacer bars on each unit. These insure a minimum joint between each unit into which sand is placed. Spacer bars help prevent contact of the edges with adjacent pavers and subsequent chipping. They are highly recommended for mechanically installed pavers. Manually installed pavers may be installed with or without spacer bars. C.

Pavers shall meet the minimum material and physical properties set forth in ASTM C 936, Standard Specification for Interlocking Interlocking Concrete Paving Units. Efflorescence shall not be a cause for rejection. 1. Average compressive strength 8000 psi (55MPa) with no individual unit under 7,200 psi (50 MPa).


Page 5


2. Average absorption of 5% with no unit greater than 7% when tested according to ASTM C 140. 3. Resistance to 50 freeze-thaw cycles, when when tested according to ASTM C 67, with no breakage greater than 1.0% loss in dry weight of any individual unit. This test method shall be conducted not more than 12 months prior to delivery of units. Note: Note: Efflorescence is a whitish powder-like deposit that sometimes appears on concrete products. Calcium hydroxide and other water-soluble materials form or are present during the hydration of Portland cement. Pore water becomes saturated with these materials, materials, and diffuses to the surface of the concrete. When W hen this water evaporates, the soluble materials remain as a whitish deposit on the concrete surface. The calcium hydroxide is converted to calcium carbonate during a reaction with carbon dioxide from the atmosphere. The calcium carbonate is difficult to remove with water. However, the efflorescence will wear off with time, and it is advisable to wait a few months before attempting to remove any efflorescence. Commercially available cleaners can be used, provided directions are carefully followed. Some cleaners contain acids that may alter the color of the pavers. D.

Pigment in concrete pavers shall conform to ASTM C 979. ACI Report No. 212.3R provides guidance on the use of pigments.

2.2

GRANULAR SUBBASE The granular subbase material shall consist of granular material graded in accordance with ASTM D 2940, as presented in Table 1. TABLE 1 SUBBASE MATERIAL GRADING REQUIREMENTS ASTM D 2940 Sieve Size

Percentages Passing

2 in. (50 mm)

100

1½ in. (37.5 mm)

90 to 100

¾ in. (19 mm) 3/8 in. (9.5 mm) No. 4 (4.75 mm)

30 to 60

No. 30 (600 µm) No. 200 (75 µm)

0 to 12 *

* In order to prevent damage by frost heaving, it may be necessary to limit the percentages of material passing the No. 200 sieve to less than shown in the tables.


Page 6


2.3

GRANULAR BASE The granular base material shall be graded in accordance with the requirements of ASTM D 2940, as presented in Table 2 TABLE 2 BASE MATERIAL GRADING REQUIREMENTS ASTM D 2940 Sieve Size

Percentages Passing

2 in. (50 mm)

100

1½ in. (37.5 mm)

95 to 100

¾ in. (19 mm)

70 to 92

3/8 in. (9.5 mm)

50 to 70

No. 4 (4.75 mm)

35 to 55

No. 30 (600 µm)

12 to 25

No. 200 (75 µm)

0 to 8 *

* In order to prevent damage by frost heaving, it may be necessary to limit the percentages of material passing the No. 200 sieve to less than shown in the tables. 2.4

BEDDING AND JOINT SAND

A.

The bedding and joint sand shall be clean, non-plastic, non-plastic, and free from deleterious or foreign matter. It can be natural or manufactured from crushed rock. Do not use limestone screenings or stone dust that do not conform to the grading requirements requirements in Table 3. When concrete pavers are subject to vehicular traffic, the sands shall be as hard as practically available.

Note: Note: The type of sand used for bedding is often called concrete sand. Sands vary regionally. Screenings and stone dust can be unevenly graded and have material passing the No. 200 (75μm) sieve. Bedding sands with these characteristics should not be used. Contact local paver contractors or manufacturers to the project and confirm sand(s) successfully used in previous similar applications. Note: Note: If the hardness of the bedding sand is not sufficient or questionable for the ® application (usually a heavily trafficked thoroughfare), contact Unilock (1-800UNILOCK) for information and specifications on assessing bedding sand durability under heavy traffic loads. B.

The bedding sand shall conform to the grading requirements of ASTM C 33 as shown in Table 3.


Page 7


TABLE 3 BEDDING SAND GRADING REQUIREMENTS ASTM C 33 Sieve Size

Percent Passing

3/8 in. (9.5 mm)

100

No. 4 (4.75 mm)

95 to 100

No. 8 (2.36 mm)

85 to 100

No. 16 (1.18 mm)

50 to 85

No. 30 (600 µm)

25 to 60

No. 50 (300 µm)

10 to 30

No. 100 (150 µm)

2 to 10

Note: Bedding sand may be used for joint sand. However, extra effort in sweeping and compacting the pavers may be required in order to fill the joints completely. It is recommendable to use sand specially gradated for joints. The gradations shown in Table 4 are recommended. Joint sand should never be used for bedding sand. C.

The joint sand shall conform to the grading requirements requirements of ASTM C 144 as shown in Table 4 below: TABLE 4 JOINT SAND GRADING REQUIREMENTS ASTM C 144

2.5

Natural Sand

Manufactured Sand

Sieve Size

Percent Passing

Percent Passing

No. 4 (4.75 mm)

100

100

No. 8 (2.36 mm)

95 - 100

95 to 100

No. 16 (1.18 mm)

70 - 100

70 to 100

No. 30 (600 µm)

40 - 75

40 to 75

No. 50 (300 µm)

10 - 35

20 to 40

No. 100 (150 µm)

2 - 15

10 to 25

No. 200 (75 µm)

0

0 to 10

EDGE RESTRAINTS The provision of suitable edge restraints is critical to the satisfactory performance of interlocking concrete block pavement. The pavers must abut tightly against the restraints to prevent rotation under load and any consequent spreading of joints. The restraints must be sufficiently stable that, in addition to providing providing suitable edge support for the paver units, they are able to withstand the impact of temperature changes, vehicular traffic and/or snow removal equipment.


Page 8


Curbs, gutters or curbed gutter, constructed to the dimensions of municipal standards (noting that these standards generally refer to cast-in-place concrete sections), are considered to be acceptable edge restraints for heavy duty installations. Where extremely heavy industrial equipment is involved such as container handling equipment, the flexural strength of the edge restraint should be carefully reviewed, particularly if a section that is flush with the surface is used and may be subjected to high point loading. Edge restraints shall be used along all unrestrained paver edges and supported on a minimum of 6 in. (150mm) of aggregate base. base.

PART 3

EXECUTIONS

3.1

EXAMINATION

A.

Verify that subgrade preparation, compacted density and elevations elevations conform to the specifications. specifications.

Note: For Note: For installation on a compacted aggregate base and soil subgrade, the specifier should be aware that the top surface of the pavers may be 1/8 to 1/4 in. (3 to 6 mm) above the final elevation after compaction. This difference in initial and final elevation is to compensate for possible minor settling. Note: Note: Compaction of the soil subgrade to at least 95% Standard Proctor Density per ASTM D 698 is recommended. Higher density or compaction to ASTM D 1557 (Modified Proctor Density) may be necessary for areas subject to vehicular traffic. Stabilization of the subgrade and/or base material may be necessary with weak or saturated subgrade soils. The Architect/Engineer should inspect subgrade preparation, elevations, and conduct density tests for conformance to specifications. B.

Verify that geotextiles, if applicable, have been placed according to specifications specificati ons and drawings.

C.

Verify that aggregate aggregate base materials, thickness, compaction, surface tolerances and elevations conform to the specifications. specifications.

Note: Note: Local aggregate base materials typical to those used for flexible pavements are recommended, or those conforming to ASTM D 2940. Compaction to not less than 95% Proctor Density in accordance with ASTM D 698 is recommended for pedestrian areas. Compaction to not less than 98% Modified Proctor Density according to ASTM D 1557 is recommended for vehicular areas. Note: Note: The aggregate base should be spread and compacted in uniform layers not exceeding 6 in. (150 mm) thickness. Recommended base surface tolerance should be plus or minus 3/8 in. (10 mm) over a 10 ft. (3 m) straight edge. The Architect/Engineer Architect/Engineer should inspect geotextile geotextile materials and placement (if applicable), base preparation, surface tolerances, elevations, and conduct density tests for conformance to specifications. Note: Note: Mechanical tampers (jumping jacks) are recommended for compaction of soil subgrade and aggregate base around lamp standards, utility structures, building Unilock Specifications

Page 9


edges, curbs, tree wells and other protrusions. Areas not accessible to roller compaction equipment should be compacted to the specified density with mechanical tampers. CAUTION CAUTION - Care shall be taken around the perimeters of excavations, buildings, curbs, etc. These areas are especially prone to consolidation and settlement. Wedges of backfill should not be placed in these areas. If possible, backfilling and compacting in these areas particularly should proceed in shallow lifts, parallel to the finished surface. D.

Verify the proper installation of the concrete curbing, in terms of location, elevation, and adherence to the specifications.

E.

Verify that the base is dry, uniform, even and ready to support sand, pavers and imposed loads.

F.

Beginning of bedding sand and paver installation installatio n shall signify acceptance of base and edge restraints.

3.2

SITE PREPARATION PREPARATION

A.

The site must be stripped of all topsoil and other objectionable materials to the grades specified.

B.

All subdrainage of underground services within the pavement area must be completed in conjunction with subgrade preparation, and before the commencement of subbase construction. construction.

Note: Note: All service trenches within the pavement area must be back filled to the subgrade level with approved material placed in uniform lifts not exceeding 4 in. (200 mm) loose thickness. Each lift must be compacted to at least 100 percent Standard Proctor Density as specified in ASTM D 698. C.

After trimming to the grades specified, the pavement is to be proof rolled to 100 percent Standard Proctor Density in the presence of the Consultant, with soft spots or localized pockets of objectionable material excavated and properly replaced with approved granular material.

D.

The subgrade shall be trimmed to within 0 to ½ in. (0 to 10mm) of the specified grades. The surface of the prepared subgrade shall not deviate by more than 3/8 in. (10mm) from the bottom edge of a 39 in. (1m) straight edge laid in any direction.

E.

The Contractor shall ensure that the prepared subgrade is protected from damage from inundation by surface water. No traffic shall be allowed to cross the prepared subgrade. Repair of any damage resulting shall be the responsibility of the Contractor and shall be repaired.

F.

Under no circumstances circumstance s shall further pavement construction proceed until the subgrade has been inspected by the Owner or the Consultant.

3.3

GRANULAR SUBBASE AND BASE INSTALLATION

A.

The subbase shall be placed in uniform lifts not exceeding 6 in., (150 mm) loose thickness and compacted to at least 100 percent Standard Proctor Density as per ASTM D 698.


Page 10


Subbase thickness shall be _____in.(____mm). B.

After proper construction construction of the edge restraints for the interlocking interlocking concrete pavement as per Section 3.4, and upon approval by the Consultant, aggregate base shall be placed in uniform lifts not exceeding 6 in. (150 mm) loose thickness. Each lift shall be compacted to at least 100 percent percent Standard Standard Proctor Maximum Dry Density. Base thickness shall be _____in. (____mm).

C.

The granular base shall be trimmed to within 0 to 3/8 3/8 in. (0 to 10 mm) of the specified grade. The surface of the prepared base shall not deviate by more than 3/8 in. (10 mm) from the bottom edge of a 10 ft. (3 m) long straight edge laid in any direction.

D.

The upper surface of the base shall be sufficiently sufficie ntly well graded and compacted to prevent infiltration of the bedding sand into the base both during construction and throughout its service life. Segregated areas of the granular base shall be blended by the application of crushed fines that have been watered and compacted into the surface.

E.

Before commencing the placing of the sand bedding course and the placement of the interlocking concrete pavers, the base shall be inspected by the Owner or the Consultant. Consultant.

3.4

EDGE RESTRAINTS

A.

Adequate edge restraint shall be provided along the perimeter of all paving as specified. The face of the edge restraint, where it abuts pavers, shall be vertical down to the subbase.

B.

All concrete edge restraints shall be constructed to dimensions and level specified and shall be supported on a compacted subbase not less than 6 in (150 mm) thick.

C.

Concrete used for the construction of edge restraints shall be air-entrained and have a compressive strength as specified. All concrete shall be in accordance with ASTM C 94 requirements.

3.5

PAVER INSTALLATION

A.

Spread the bedding bedding sand evenly evenly over the base base course and screed screed to a nominal 1 in. (25 mm) thickness, not exceeding 1 ½ in. (40 mm) thickness. The screeded sand should not be disturbed. Sufficient sand shall be placed in order to stay ahead of the laid pavers. Do not use the bedding sand to fill depressions in the base surface.

Note: The spread sand shall be carefully maintained in a loose condition, and protected against incidental compaction, both prior to and following screeding. Any incidentally compacted sand or screeded sand left overnight, overnight, shall be loosened before further paving units are placed. Sand shall be lightly screeded in a loose condition to the predetermined depth, only slightly ahead of the paving units. Under no circumstances shall the sand be screeded in advance of the laying face to an extent to which paving will not be complete on that day. Unilock Specifications

Page 11


Screed sand shall be fully protected against incidental compaction, including compaction by rain. Any screeded sand which is incidentally compacted prior to laying of the paving unit, shall be removed and brought back to profile in a loose condition. Neither pedestrian nor vehicular traffic shall be permitted on the screeded sand. The Contractor shall screed the bedding sand using either an approved mechanical spreader (e.g.: an asphalt paver) or by the use of screed rails and boards. B.

Initiation of paver placement shall be deemed to represent acceptance of the pavers.

C.

Pavers shall be free of foreign material before installation. installation.

D.

Pavers shall be inspected for color distribution distributio n and all chipped, damaged or discolored pavers shall be replaced.

Note: Note: Color Blending - Paving units shall be installed from a minimum of 3 bundles simultaneously drawing the paver vertically rather than horizontally. (Color variation occurs with all concrete products. This phenomenon is influenced by a variety of factors, e.g. moisture content, curing conditions, different aggregates and, most commonly, from different production runs.) By installing from a minimum of three bundles simultaneously, variation in color is dispersed and blended throughout the project. E.

The pavers shall be laid in the pattern(s) as shown on the drawings. String lines or chalk lines on bedding sand should be used to hold all pattern lines true.

F.

Joints between the pavers on average shall be between 1/16 in. and 1/8 in. (2 mm to 4 mm) wide. In order to maintain the desired pattern, joint spacing must be consistent. This spacing must also be provided for the first row abutting the edge restraint.

Note: Installing pavers too tightly may lead to chipping at the edges. G.

Gaps at the edges of the paved area shall be filled with cut pavers.

Note: Note: Units cut no smaller than one-third of a whole paver are recommended along edges subject to vehicular traffic. H.

Pavers to be placed along the edge shall be cut with a double blade paver splitter or masonry saw.

Note: Note: The use of infill concrete or discontinuities in patterns will not be permitted except along the outer pavement boundaries, adjacent to drains and manholes. I.

Upon completion of cutting, the area must be swept clean of all debris to facilitate inspection and to ensure pavers are not damaged during compaction. (Debris or sand particles left on pavers which are being compacted can cause point loading which may chip, scrape or break the paver.)

J.

After sweeping and prior to compaction, the paved area must be inspected by the owner or consultant to ensure satisfactory color blending. Pavers can be moved easily at this time to achieve good color distribution.


Page 12


K.

Low amplitude, high frequency plate compactor shall be used to compact the pavers into the sand. The compactor shall transmit an effective force not less 2 than 75 kN per square metre (1600 Lb/ft ) of plate area. The frequency of vibration shall be within the range of 75 to 100 Hz. Use Table 5 below to select size of compaction equipment: TABLE 5 PAVER THICKNESS AND REQUIRED MINIMUM COMPACTION FORCE Paver Thickness Compaction Force 2 3/8 in. (60 mm)

3000 lbs [13 kN]

2 3/4 in. (70 mm) & 3 1/8 in. (80 mm)

5000 lbs [22 kN]

Note: Use Note: Use of a urethane plate compactor pad is recommended to minimize any scuffing of the paving stone surface. L.

The pavers shall be compacted to achieve consolidation consolidatio n of the sand bedding and brought to level and profile by not less than three passes. Initial compaction should proceed as closely as possible following the installation of the paving units and prior to the acceptance of any traffic or application of sweeping sand.

M.

Any units that are structurally damaged during compaction shall be immediately immediat ely removed and replaced.

N.

Dry joint sand shall be swept into the joints until the joints are full. This will require at least two or three passes with the compactor. Do not compact within 3 ft. (1 m) of the unrestrained edges of the paving units.

O.

All work to within 3 ft. (1 m) of of the laying face must be left fully compacted with sand-filled joints at the completion of each day.

P.

Excess joint sand shall be swept off when the job is complete.

3.06

FIELD QUALITY CONTROL

A.

Final elevations shall be checked for conformance to the drawings after removal of excess joint sand.

B.

All surface and pavement structures shall be true to the lines and levels, grades, thickness and cross sections shown on the drawings. All pavements shall be finished to lines and levels to ensure positive drainage drainage at all drainage outlets and channels. In no case shall the cross-fall of any portion of pavement be less than 2 percent. The final surface elevations shall not deviate more than 3/8 in. (10 mm) under a 10 ft. (3 m) long straight edge.

C.

The surface elevation of pavers shall be 1/8 to 1/4 in. (3 to 6 mm) above adjacent drainage inlets, concrete collars or channels.

END OF SECTION Unilock Specifications

Page 13

SECTION 32 94 56 PLANTING SOIL for SILVA CELLS

PLANTING SOIL for SILVA CELLS

This specification defines material and performance requirements for soils which are to be used within the Silva Cell system. The SPECIFICATION EDITOR must select the type of soil appropriate to each particular application, reflecting local market availability and specific application requirements such as soil type, pH, and drainage characteristics for the project. The SPECIFICATION EDITOR is responsible for selecting from the following soil types (see specification for requirements of each): 2.1 TOPSOIL, IMPORTED OR HARVESTED HARVESTED (for use as a component of planting soil mix): Imported topsoil meeting specific requirements for organic matter, cleanliness, pH, and source location. 2.2 EXISTING SITE SOIL (for use as a component of planting soil mix): Existing site soil meeting specific requirements. 2.5 PLANTING SOIL – EXISTING SOIL MIX: Planting mix of existing site soil and compost. 2.6 PLANTING SOIL - SILVA CELL STANDARD SOIL MIX: Planting mix of topsoil, compost, and course sand. 2.7 PLANTING SOIL – SILVA CELL BIORETENTION SOIL MIX (for stormwater applications): Planting mix of compost and coarse sand mixed to achieve specific water permeability.

NOTE: This specification may be modified to accept municipally-approved bioretention soil mixes and related specifications. Some elements in these specifications require coordination with project drawings. These items are noted “as indicated on plans or drawings.” See the DeepRoot website (www.deeproot.com) for questions. DeepRoot can assist in evaluating and sizing project-specific design elements for Silva Cells stormwater applications.

32 94 56 – Planting Soil for Silva Cells © 2010 Deep Root Partners, L.P. Version 2.20 Updated 7/1/2010

-1-

SECTION 32 94 56 PLANTING SOIL for SILVA CELLS

PART 1 - GENERAL

1.1

RELATED DOCUMENTS A.

1.2

Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section.

SUMMARY A.

Section Includes: 1.

B.

Related Sections: 1.

1.3

Furnishing and installation of Planting Soil within the Silva Cell system.

Division 32 – Exterior Improvements a. Section 32 94 50 Silva Cells b. Section 32 94 53 Root Barrier

DEFINITIONS A.

Planting Soil: Soil, of a variety of texture s, defined in this section, intended to fill the Silva Cell frames and other planting spaces to support the growth of trees and other plants.

B.

Silva Cells: Plastic structural cellular system with post, beams and de cks designed to be filled with planting soil for tree rooting and/or used for water storage and support vehicle loaded pavements.

C.

Soil Peds: Clumps of soil that naturally aggregate during the soil building process. Creating a soil mix shall be done in a way that maintains the soil peds. Refrain from over-mixing.

D.

Tree: A perennial woody plant with one or several trunks and a distinct crown and intended to become large enough to shade people and or vehicles.

1.4

SUBMITTALS A.

Upon forty-five (45) days prior to start of installation of items in this section, the Contractor shall provide submittals required in this section to t he landscape architect for review and approval.


-2-

SECTION 32 94 56 PLANTING SOIL for SILVA CELLS B.

Product Data: For each type of product, submit submit manufacture's product literature with technical data sufficient to demonstrate that the product meets the requirements of the specification.

C.

Material Certificates: Submit material certificates for all natural and bulk material indicating that the material meets the requirements of the specification.

D.

Soil test analysis: Submit soil testing results from an approved soil-testing laboratory for each soil and soil mix for approval. 1. All testing will be at the expense of the Contractor. The landscape architect may request additional planting mix tests on different mix component ratios in order to attain results that more closely meet the mix requirements. 2. The testing laboratory shall be a member of the Soil Science Society of America's, North American Proficiency Testing Program (NAPT), and have a m inimum of five years experience with the test protocols of the United States Golf Association Green Section. 3. All testing shall comply with the requirements of the Methods of Soil Analysis Part 1 and 3, published by the Soil Sc ience Society of America. 4. Soil testing shall be as required for each product an as defined below: a. Physical analysis. 1. Particle size analysis shall shall be provided for gravel, clay, silt, and sand fractions 2. USDA soil soil texture 3. Fines Modulus Index for each sand source 4. Infiltration testing shall be be done at 80 to 85% compaction at proctor density using ASTM D 698-91. Test Results shall include bulk density b. Chemical analysis. Note that nutrient levels and chemical analysis analysis shall include recommendations from the testing laboratory for r anges of each element appropriate for the types of plants to be grown in the soil mix. 1. Nutrient levels by parts per per million including including phosphorus, potassium, calcium, magnesium, manganese, iron, copper, zinc and calcium 2. Percent organic content 3. pH 4. Soluable salt by electrical conductivity conductivity 5. Cation Exchange Capacity (CEC) (CEC)

E.

Samples for Verification: Submit two gallon samples of each pro duct and material where required by the specification to the landscape architect for approval. approval. Label samples to indicate product, source location, specification number, c haracteristics, and locations in the Work. Samples will be reviewed for appearance only. Compliance with all other requirements is t he exclusive responsibility of the contractor. Delivered materials shall closely match the samples.


-3-

SECTION 32 94 56 PLANTING SOIL for SILVA CELLS 1.

1.5

Planting soil shall be labeled as to the per centage of each component in the mix.

SOIL INSTALLATION MOCK UP AND COMPACTION EVALUATION A.

Prior to the installation of planting soil within the Silva Cells, construct a mock up of the complete installation at the site. The installation of the mock up shall be in the presence of the landscape architect.

B.

The Silva Cell mock up shall be as outlined in Specification Section 32 94 30 Silva Cells.

1.6

SCHEDULING A.

General: Prior to the start of Work, prepare a detailed schedule of the work for coordination with other trades.

B.


C.

Where possible, schedule the installation of planting soil within the Silva Cells immediately after the installation of the Silva Cell frames. Protect installed Silva Cells from damage in the event that work must occur over or adjacent to the completed Silva Cells.

1.7

QUALITY ASSURANCE A.

1.8

Installer Qualifications: Soil within the Silva Cells shall be installed by the same contractor who is installing the Silva cells. See Specification Section 32 94 50 Silva Cells for installer qualifications.

PERMITS AND CODE COMPLIANCE A.

1.9

Comply with applicable requirements of the laws, codes, ordinances and regulations of Federal, State and Municipal authorities having jurisdiction. Obtain necessary permits/approvals from all such authorities.

DELIVERY, STORAGE, AND HANDLING A.

Packaged Materials: Deliver packaged materials in original, unopened containers showing weight, certified analysis, name and address of manufacturer, and indication of conformance with state and federal laws, if applicable. applicable. Protect materials from deterioration during delivery and while on the project site.

B.

Bulk Materials: Do not deliver or place backfill, soils and soil amendments in frozen, wet, or muddy conditions.


-4-

SECTION 32 94 56 PLANTING SOIL for SILVA CELLS 1. Bulk materials shall be stored and staged in a location approved by landscape architect or as indicated on the plans and in a manner that prevents damage to the site or the stored materials. 2. Provide protection including tarps, plastic and or matting between all bulk materials and any finished surfaces sufficient to protect the finish material. C.

Provide erosion-control measures to prevent erosion or displacement of bulk materials and discharge of soil-bearing water runoff or airborne dust to adjacent properties, water conveyance systems, and walkways. Provide additional sediment control to retain excavated material, backfill, soil amendments and planting mix within the project limits as needed.

D.

Protect Silva Cells from damage during installation of planting soil.

1.10

PROJECT CONDITIONS

A.

During the installation of Planting Soil within the Silva cells comply with all project conditions in Specification Section 32 94 50 Silva Cells

B.

Weather Limitations: Do not proceed with work when subgrades, soils and planting planting soils are in a wet, m uddy or frozen condition.

1.11 A.

1.12 A.

PROJECT WORK Coordinate installation with all other work that may impact t he completion of the Silva Cell installation.

PRECONSTRUCTION MEETING Prior to the start of the installation of Planting Soil within the Silva Cells, meet at the site with the landscape architect, general contractor and the Silva Cell installer to review installation layout, procedures, means and methods.

PART 2 - PRODUCTS

NOTE TO SPECIFICATION EDITOR: select one or more of the following planting soil components (topsoil, compost, and/or sand) to meet project requirements. Local soil types may require modification to this specification.

2.1

TOPSOIL, IMPORTED OR HARVESTED (FOR USE AS A COMPONENT OF PLANTING SOIL MIX)


-5-

SECTION 32 94 56 PLANTING SOIL for SILVA CELLS A.

Fertile, friable, loamy soil, free from subsoil, refuse, roots, heavy or stiff clay, stones larger than 1 inch, contaminants, noxious seeds, sticks, brush, litter, and other deleterious substances; suitable for the germination of seeds and the support of vegetative growth. Soil source location and extent of area suitable for harvest shall be approved by the landscape architect and shall comply with all local regulations governing the removal of topsoil.

B.

Topsoil texture shall be loam, sandy loam to sandy clay loam, suitable for the germination of seeds and the support of vegetative growth, which is a naturally produced soil.

C.

Physical Requirements for Topsoil Parameter Gravel > 2mm Silt .002-.05 mm & Clay < .002mm 

Units % Dry Weight % Dry Weight % Dry Weight

Acceptable Range Less than 10% 15-30% 20-35%

Chemical Requirements for Topsoil Parameter Organic Matter pH Soluble Salt* Cation Exchange Capacity Nutrient Analysis

Units % Dry Weight pH Units mmhos/cm or dS/m meQ/100g PPM

Acceptable Range 2-8% 5.0 to 7.5 3.5 or less >8 As required for the plants specified

 

D.

   



* by electrical conductivity of a 1:1 soil water sample at 25 degrees degree s E.

Submit soil testing results for approval by the Landscape Architect, as defined in Section 1, that the m aterial meets the above physical and chemical requirements.

F.

Submit two gallon sample for verification and approval by the Landscape Arc hitect.

2.2

EXISTING SITE SOIL (FOR USE AS A COMPONENT OF PLANTING SOIL MIX)

A.

Existing site soils shall be used only after excavated and approved by the project Landscape Architect.

B.

Existing site soil that is clean, coarse grained fill soil meeting the requirements of the Unified Soil Classification system for soil type GW, GP, GC with less than 40% fines, SW, and SC with less than 40% fines. Soil shall be sufficiently friable to be mixed with the required compost and installed into the Silva Cell system.

C.

Existing site soil shall shall be free of, trash and other debris. It shall be free of stones, stumps, roots, or other similar objects larger than three inches, and shall be free of toxic material injurious to plant growth.


-6-

SECTION 32 94 56 PLANTING SOIL for SILVA CELLS D.

Physical Requirements for Existing Site Soil Parameter Units Gravel > 2mm % Dry Weight Silt .002-.05 mm & Clay < .002mm % Dry Weight  

E.

Chemical Requirements for Existing Site Soil Parameter Units Organic Matter % Dry Weight pH pH Units Soluble Salt* mmhos/cm or dS/m Cation Exchange Capacity meQ/100g Nutrient Analysis PPM     

Acceptable Range Less than 10% Combined 20-40%

Acceptable Range 0.05-8% 5.0 to 7.5 4 or less >5 As required for the plants specified

* by electrical conductivity of a 1:1 soil water sample at 25 degrees degree s F.

Submit soil testing results for approval by the Landscape Arc hitect, as defined in Section 1, that the material meets mee ts the above physical and chemical requirements.

G.

Submit product data, material certificates, and r esults of soil test analysis showing that these requirements have been met, for approval by the Landscape Architect.

H.

Submit two gallon sample for verification and approval by the Landscape Arc hitect.

2.3

COMPOST (FOR USE AS A COMPONENT OF PLANTING SOIL MIX) A.

Compost shall meet the requirements of the US Composting Council “Landscape Architecture/Design Specifications for Compost Use”, section “Compost as a Landscape Backfill Mix Component”, with the following additional requirements: 1.

B.

Compost feedstock shall be yard waste trimmings and/or source-separated municipal solid waste to produce a fungi-dominated compost. Compost shall not be derived from biosolids or industrial residuals.

Compost testing and analysis: Compost analysis shall be provided by the Compost supplier. Before delivery of the Compost, the supplier must provide the following documentation: 1.

A statement that the Compost meets federal and state health and safety regulations.

2.

Compost testing methodologies and sampling procedures shall be as provided in Test methods for the Examination of Composting and Compost (TMECC), as published by the US Composting Council.


-7-

SECTION 32 94 56 PLANTING SOIL for SILVA CELLS C.

Submit supplier’s literature and material certification that includes physical analysis and chemical analysis of the compost.

D.

Submit two gallon sample for approval by the Landscape Architect.

2.4 A.

SAND (FOR USE AS A COMPONENT OF PLANTING SOIL MIX) Coarse concrete sand, ASTM C-33 Fine Aggregate, with a Fines Modulus Index of 2.8 and 3.2. 1. Sands shall be clean, sharp, natural sands free of limestone, shale and slate particles. 2. Sand PH shall be lower than 7.0 3. Provide the following particle size distribution: Sieve 3/8" (9.5mm) No 4 (4.75mm) No 8 (2.36mm) No 16(1.18mm) No30 (.60mm) No50 (.30mm) No100 (.15mm)       

B.

2.5 A.

Percent Passing 100 95-100 80-100 50-85 25-60 10-30 2-10

Submit manufacturer’s testing data for approval that the material complies with the above requirements.

PLANTING SOIL – EXISTING SOIL MIX Planting Mix of existing site soil and compost mixed to the following proportion: Material Existing site soil Compost  

% by volume 80% 20%

B.

Do not screen or over mix to maintain soil peds. Soil peds or clumps up to 4 inches in diameter are acceptable in the soil mix.

C.

Make chemical modifications to the soil mix as indicated by soil tests for the types of plants to be grown.

D.

Once mixing is complete, cover stock piles with tarps or heavy plastic to protect soil from drying, saturation and erosion. e rosion.

E.



-8-

SECTION 32 94 56 PLANTING SOIL for SILVA CELLS 2.6 A.

PLANTING SOIL - SILVA CELL STANDARD SOIL MIX Planting Mix of topsoil, compost, and course sand mixed to the following proportion: Material Compost Coarse Sand Topsoil (for use as a base in a planting soil mix)   

% by volume 12-17% 35-50% 35-50%

B.

Adjust the ratio of the components to achieve infiltration rates between 0.75 and 1.75 inches per hour when compacted to 80-85% 8 0-85% of maximum dry density. Submit multiple mix ratios for infiltration rates to establish the correct mix ratio for the available topsoil.

C.

Do not screen or over mix to maintain soil peds. Soil peds or clumps up to 4 inches in diameter are acceptable in the soil mix.

D.

Submit testing results for infiltration rates at 80-85% compaction for approval by the Landscape Architect.

E.

Submit two gallon sample for approval by the Landscape Archite ct.

2.7

PLANTING SOIL - SILVA CELL C ELL BIORETENTION SOIL MIX (for stormwater applications)

NOTE TO SPECIFICATION EDITOR: Bioretention soils are used for stormwater or water harvesting applications for filtration of water contaminants. Tree species selected for planting in this soil mix should be compatible with the expected hydrologic extremes within such a system. A.

Planting mix of compost and coarse sand mixed to the following proportion. Material Coarse Sand Compost

 

% by volume 80% 20%

B.

Infiltration rates shall be a minimum 4 inches per hour, when compacted to 80-85% of maximum dry density.

C.

Planting mix shall be thoroughly mixed prior to installation.

D.

Submit testing results for infiltration rates at 80 -85% compaction for approval by the Landscape Architect.

E.


2.8

PLANTING SOIL – MUNICIPALLY APPROVED BIORETENTION SOIL MIX (FOR STORMWATER APPLICATIONS)


-9-

SECTION 32 94 56 PLANTING SOIL for SILVA CELLS A.

There is a growing list of municipalities and other governing agencies that have custom bioretention soil mixes. The following have been approved for substitution in the Silva Cell system. Municipally Approved Bioretention Soil shall shall comply with all local requirements and the submittal requirements of these specifications for Bioretention Soil. 1. Washington State Department of Ecology a.

Planting soil shall meet the most current requirements as outlined in Volume III-Hydrologic Analysis and Flow Control BMPs, Appendix III-C, Washington State Department of Ecology Low Impact Development Design and Flow Modeling Guidance, Section 7.7.1.

2. City of Seattle a.

Planting soil shall meet the requirements of the most current requirements as outlined in the City of Seattle Bioretention Soil Specification.

PART 3 - EXECUTION

3.1

Install planting soil in Silva Cells and mulch as described in Sec tion 32 95 40 Silva Cells.

END OF SECTION


-10-

SECTION 32 94 56 PLANTING SOIL for SILVA CELLS Submittal Checklist for Reference Only Contractor shall provide submittals required to the landscape architect for review and approval. The Submittal process may take up to two months prior to installation of the Silva Cell system and should be executed as soon as possible after the contract is awarded. All testing will be at the expense of the Contractor.

SOIL COMPONENT SUBMITTALS – PRIOR TO PLANTING SOIL MIXI NG 2.1 TOPSOIL - IMPORTED OR HARVESTED (for use as a component of planting soil mix)   Suppliers literature and material certification that includes physical analysis and chemical analysis with recommendations for amendments Two gallon sample  

2.2 EXISTING SITE SOIL (for use as a component of planting soil mix) Suppliers literature and material certification that includes physical analysis and  chemical analysis with recommendations for amendments Two gallon sample 



2.3 COMPOST (for use as a component of planting soil mix) Certificate of compliance with federal and state health and safety regulations  Lab analysis for physical, organic and chemical requirements, and feed stock  percentage Two gallon sample 



2.4 SAND (for use as a component of planting soil mix) Suppliers literature and material certification that includes physical analysis, fines  modulus index and chemical analysis with recommendations for amendments  Two gallon sample

SOIL MIX SUBMITTALS – FOR FINAL F INAL APPROVAL BY LANDSCAPE ARCHITECT 2.5 PLANTING SOIL – EXISTING SITE SOI L MIX   Two gallon sample, labeled with the percentage of each soil component in the mix 

2.6 PLANTING SOIL - SILVA CELL STANDARD SOIL MIX  Testing results for infiltration rates at 80 and 85% of maximum dry density Two gallon sample, labeled with the percentage of each soil component in the mix 



2.7 PLANTING SOIL - SILVA CELL C ELL BIORETENTION SOIL MIX (for stormwater applications) Testing results for infiltration rates at 80 and 85% of maximum dry density   Two gallon sample, labeled with the percentage of each soil component in the mix


-11-

Appendix E

Bloor-Dovercourt Bloor -Dovercourt Demonstration Project

PAVING STONE GRATE

Appen Ap pendi di x B, B , Terms Term s of o f Referen Ref erence ce

PavingStone Grate II Descriptive Specifications 1.0

Dimensions .1 .2 .3

2.0 2.0

Height Width of PavingStone Grate Length of PavingStone Grate

-

100mm 1300mm 1300mm

Formed Laser Cut and Welded Welded Steel Steel Compon ents .1 .2

3.0

All steel parts shall be of high grade material 300W min. requirement. Welding materials: In accordance with CSA W48 Series

Paving Ston e Grate .1 .2 .3 .4 .5 .6

4.0

9.5mm HR steel All butt joints to be welded continuously Height of inner vertical Flange Width of Grate Length of Grate Hot Dip Galvanize finish

100mm 1300mm 1300mm

Hori zont al Plate .1 .2 .3 .4 .5 .6

5.0

One component reinforced design Four (4) 100mm offset non threaded locate holes for securing plate component All butt joints to be welded continuously Holes to be spaced and aligned equally at corners Four (4) 9.5mm thick reinforcing members centered equally on each side of plate Hot Dip Galvanize finish

Vertic al Flange .1 .2 .3 .4 .7 .8

6.0

Galvanized High grade steel Flange total height - 100mm Outside width of flange opening - 620mm Width of flange inlet opening - 600mm Four (4) vertical slotted holes centered for component mounting Hot Dip Galvanize finish

Base Plate Root Rain Inlet .1

7.0 7.0

Two (2) maximum 90mm holes for through mounting of RootRain System as required

Galvanization Galvanization Preparation and Finish ing .1 .2 .3 .4

Sandblast all steel parts to remove any mill scale prior to galvanization. Electroplate steel parts that would be injured when exposed to hot-dipped galvanization Perform all galvanization operations in accordance with CAN/CSA – G164-M92. No drilling or threading operations to be performed after the galvanization.

STRIP DRAIN

ROOTRAIN LINEAR STRIP DRAIN II

Appendix B, Terms of Reference of Reference

RootRain Linear Drain Descriptive Specifications 1.0

Dimensions .1 .2 .3

2.0

Height Width of linear of linear drain Length of linear of linear drain

‐ ‐ ‐

76mm 108mm varies

Formed Laser Cut and Welded Steel Components .1 .2

3.0

All steel parts shall be of high of high grade material 300W min. requirement. Welding materials: In accordance with CSA W48 Series

Linear Drain Trough .1 .2 .3 .4 .5 .6

4.0

14GA HR steel All butt joints butt joints to be welded continuously ‐ Height of trough of trough ‐ Width of trough of trough ‐ Length of trough of trough Hot Dip Galvanize finish

70mm 108mm varies

Horizontal Gusset .1 .2 .3 .4 .5

5.0

14GA HR galvanized angles, continuous weld on ends Two (2) threaded holes to fit applicable thread size All butt joints butt joints to be welded continuously Horizontal Gusset to be spaced and aligned equally along the length Hot Dip Galvanize finish

Lid .1 .2 .3 .4 .5 .6 .7

6.0

Galvanized High grade steel ‐ Lid height 6mm ‐ Outside width of lid of lid 108mm ‐ Width of lid of lid inlet openings 12mm Lid ribs detail 50 x 108mm spaced evenly apart ‐ Lid hardware 316 stainless steel counter sunk flat head Hex Drive screws. Hot Dop Galvanize finish

Base Plate Root Rain Inlet .1 .2

7.0

52mm reducing tabbed inlet with debris collector Vertical triangle pre‐screen for larger debris

Concrete Retaining Tab .1

8.0

Five (5) 25mm x 100mm 14GA HR Galvanized tabs aligned on one lower edge of trough. of trough.

Galvanization Preparation and Finishing .1 .2 .3 .4

Sandblast all steel parts to remove any mill scale prior to galvanization. Electroplate steel parts that would be injured when exposed to hot‐dipped galvanization Perform all galvanization operations in accordance with CAN/CSA – CAN/CSA – G164‐M92. No drilling or threading operations to be performed after the galvanization.

Root Rain Linear Strip Drain An installed RootRain Drain System should incorporate the following: Correct grate type Correct channel type and size Minimum grade 3,000psi compressive strength cement concrete surround Strip drain units are installed in a continuous trench, and are fully encased with concrete. 1. Excavation: Excavate trench to accommodate trench drain system. Excavation should be made around the center line. Excavation must be sufficient enough to accommodate each of the of the following: Strip drain width and depth dimensions. Concrete surround dimensions ‐ a minimum of 4” of 4” (Load Class A) of concrete of concrete on all sides, Specific loading and ground conditions will increase excavation size. For sloped systems, excavate base to roughly follow fall of trench of trench drain run. Ensure all loose material is removed and base is compacted. Run string line and laser level at finished surface level along full length of excavation of excavation to ensure trench is installed at correct grade. 2. Layout and outlet installation All installations should start from the outlet point. Determine type of outlet of outlet required and its position Install the outlet channel/catch basin and set haunch Select the numbered sloping channel units in order from deepest (highest channel number) to shallowest Install channels working away from the outlet 3. Trench drain installation Strip drain units need to be supported at correct height and held securely in place to avoid movement during concrete pour. There are a number of options of options available to support Strip drain units. Using a timber strap wide enough to span the trench position the strip drain to the correct height using a screw threaded in the gussets

Timber strap positioned and adjusted to the correct height for the strip drain Trench over excavated to receive the linear strip drain and provide for sufficient volumes of concrete of concrete

Citygreen Urban Ltd 24 A Corydon Place Cambridge ON N1R7L5 I T: 1866 282 2743 I F: 519 623 7333 www.citygreen.com

Root Rain Linear Strip Drain 4. Strip bracing : To prevent the channel walls being distorted by the pressure of concrete, of concrete, grates should be installed in the channel. The grates should be suitably wrapped to protect from concrete splash. Shims or spacers placed along each side allow easy removal of the of the grating. 5. Concrete pour: Concrete should have minimum 3,000 psi compressive strength. Concrete should be poured evenly (both sides of channel) and carefully to avoid dislodging channels. A wand/needle type vibrator should be used to ensure concrete distributes evenly underneath and around channels. 6. Pavement finishing : The top of the of the adjacent pavement must be above the grating level by approximately 1/8" (3 mm). Brick pavers should be set slightly above the trench edge. First brick course should be set on mortar/concrete. Care should be taken with asphalt rolling machines to avoid damage to trench edge. 7. Completing trench installation: i ii iii iv v

Remove grates and remove protective wrapping. Remove debris from trench drain and make sure outlet pipes are clear. Install debris buckets in catch basins, if required. if required. Flush trench run to check for pipe work blockages. Unblock if necessary. if necessary. Empty debris buckets and clean out pipe connections, if necessary. if necessary. Re‐install trash buckets. Re‐install grates in proper position ensuring they are securely fastened down.

The RootRain linear trench drain is now ready for use. 8. Maintenance: Regular inspections of the of the RootRain trench drains are recommended. Frequency will depend on local conditions and environment, but should be at least annually. Inspections should cover: • Grates and locking devices • Catch basins and trash buckets • Concrete surround and adjacent paving All items should be inspected for damage, blockage or movement. Compare with site drawings if necessary. if necessary.


Root Rain Linear Strip Drain

Maintenance Guidelines: i ii iii iv v vi vii

Remove grates Remove debris from channel Flush channels with water or high pressure washer (do not use boiling water or aggressive cleaning agents) Repair damaged surfaces where necessary with an appropriate repair kit Renew joint Renew joint seals as required Empty debris buckets and clean out pipe connections, if necessary. if necessary. Re‐install trash buckets. Re‐install grates in proper position ensuring they are securely back in place


50 Park Road Toronto, Toront o, Ontari o M4W 2N5 T 416 968 9479 F 416 968 0687 www.dtah.com

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