Changes

==Overview==

==Overview==

Modern green roofs are a rapidly developing  commercial market in Ontario. Their primary benefit as a LID technology is in maximizing [[evapotranspiration]] for water balance targets.

Modern green roofs are a rapidly developing  commercial market in Ontario. Their primary benefit as a LID technology is in maximizing [[evapotranspiration]] for water balance targets.

Green roofs are sometimes referred to as 'ecoroofs', 'vegetated roofs', 'living roofs'.

 

 

 

 

 

Green roofs are sometimes referred to as 'ecoroofs', 'vegetated roofs', or 'living roofs'.

{{textbox|Green roofs are ideal for:

{{textbox|Green roofs are ideal for:

*Sites without significant space at ground level for infiltration,

*Sites without significant space at ground level for infiltration,

*Projects looking for accreditation with LEED v.4}}

*Projects looking for accreditation with LEED v.4}}

Extensive green roofs are the most commonly used  type of green roof used for stormwater in our region.

Extensive green roofs are the most commonly used  type of green roof used for stormwater management in our region.

{|class="wikitable"

{|class="wikitable"

|Usually visual only<br>i.e. inaccessible||Often accessible

|Usually visual only<br>i.e. inaccessible||Often accessible

|}

|}

Intensive green roofs are commonly used for amenity space on condo developments or sometimes as urban farms. They are sometimes referred to as roof gardens and encompass diverse uses, design priorities and technical specifications.  In the most extreme examples, many urban parkettes  including large shade trees may be included in this class, if they have parking garages beneath. As such the discussion on this page is limited to extensive green roofs.8

Intensive green roofs are commonly used for amenity space on medium- and high-rise residential developments or sometimes as urban farms. They are sometimes referred to as roof gardens and encompass diverse uses, design priorities and technical specifications.  In the most extreme examples, many urban parkettes  including large shade trees may be included in this class, if they have parking garages beneath. As such the discussion on this page is limited to extensive green roofs.  

'''The fundamental components of an extensive green roof are:'''

'''The fundamental components of an extensive green roof are:'''

*a roof able to withstand the load

*a roof structure able to support the design load

*a roof membrane resistant to root penetration

*a waterproof membrane resistant to root penetration

*a drainage layer

*a drainage layer

*a filter layer

*a filter layer

[[File:TBG2014.jpg|thumb|Same extensive green roof illustrating the increased biodiversity resulting from very light maintenance over 10 years]]  

[[File:TBG2014.jpg|thumb|Same extensive green roof illustrating the increased biodiversity resulting from very light maintenance over 10 years]]  

Green roofs offer a variety of co-benefits beyond stormwater management. In urban centers they are often constructed to accommodate a roof terrace or amenity space. In this scenario the direct stormwater capture benefit is restricted to the areas with vegetation planted.  Another increasingly popular use for rooftop space is for urban farming. Again, the direct stormwater capture benefit is restricted to the areas with planters.

Green roofs offer a variety of co-benefits beyond stormwater management. In urban centers they are often constructed to accommodate a roof terrace or amenity space. In this scenario, the direct stormwater capture benefit is restricted to the areas with vegetation planted.  Another increasingly popular use for rooftop space is for urban farming. Again, the direct stormwater capture benefit is restricted to the areas with planters.

To maximize the utility of a green roof as a low impact development tool, coverage with planting should be maximized. In many cases this means only inaccessible spaces are used.

To maximize the utility of a green roof as a low impact development tool, coverage with planting should be maximized. In many cases this means only inaccessible spaces are used.

The choice of vegetation on an extensive green roof is insignificant in stormwater management compared to the choice of planting medium or the provision of irrigation. The vegetation should be selected to be resilient to both very wet and very dry periods.''Sedum'' species are the most common choice, demonstrating excellent longevity in systems with or without irrigation.  

The choice of vegetation on an extensive green roof is insignificant in stormwater management compared to the choice of planting medium or the provision of irrigation. The vegetation should be selected to be resilient to both very wet and very dry periods.''Sedum'' species are the most common choice, demonstrating excellent longevity in systems with or without irrigation.  

Some projects expect the low growing ''Sedum'' to  remain in graphic designs according to species and flower color. This is not a realistic expectation without significant maintenance costs. Instead project stakeholders should be prepared early in the design process to embrace the green roof as a living and evolving ecosystem. Designs which incorporate both ''Sedum'' and native species can help with this.

Some projects expect the low growing ''Sedum'' to  remain in graphic designs according to species and flower color. This is not a realistic expectation without significant maintenance costs. Instead project stakeholders should be prepared early in the design process to embrace the green roof as a living and evolving ecosystem. Designs which incorporate both ''Sedum'' and native species can help with this.

<div class="toccolours mw-collapsible mw-collapsed">

<div class="toccolours mw-collapsible mw-collapsed">

==Green roof plants==

==Green roof plants==

===Drains and vegetation free zones===

===Drains and vegetation free zones===

Vegetation free areas are often required around the perimeter of the roof to reduce wind uplift, on larger areas requiring firebreaks, for access paths and around drains.  To prevent accumulation of sediment and migration of the vegetation, the vegetation free areas should not be filled with decorative aggregate or river rock.  Instead concrete pavers or other surfaces that do not actively trap particles will reduce weeding maintenance.

Vegetation free areas are often required around the perimeter of the roof to reduce wind uplift, on larger areas requiring firebreaks, for access paths and around drains.  To prevent accumulation of sediment and migration of the vegetation, the vegetation free areas should not be filled with decorative aggregate or river rock.  Instead concrete pavers or other surfaces that do not actively trap particles will reduce weeding maintenance.

==Performance==

==Performance==

===Proprietary systems===

===Proprietary systems===

{{:disclaimer}}

{{:disclaimer}}

*[http://www.nlsm.ca/ Next Level Stormwater Management]

*[http://www.nlsm.ca/ Next Level Stormwater Management]

*[http://www.liveroof.com/ LiveRoof]

*[http://www.vitaroofs.com/ VitaRoofs]

*[http://www.ginkgosustainability.com/ Ginkgo Sustainability]

*[https://www.zinco.ca/ Zinco]

*[https://www.zinco.ca/ Zinco]

 

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[[Category:Green infrastructure]]

[[Category:Green infrastructure]]