Changes

<gallery mode="packed">

<gallery mode="packed">

Roof Drain.jpg | Example of gravel edging around a roof, which needs weeding. <br>Photo credit: jchill

Roof Drain.jpg | Example of gravel edging around a roof, which needs weeding.

Red Drain.jpg| Example of gravel edging around a roof drain, which needs weeding. <br>Photo credit: jchill 

Red Drain.jpg| Example of gravel edging around a roof drain, which needs weeding.  

Native Child.jpg| The amenity value of this roof is enhanced by the tall and climbing plants screening the high safety fences. <br>Photo credit: jchill

Native Child.jpg| The amenity value of this roof is enhanced by the tall and climbing plants screening the high safety fences.  

PondRd2.jpg| Very light maintenance has permitted a stand of Mullein to develop on this prairie style green roof, increasing the biodiversity value.  

PondRd2.jpg| Very light maintenance has permitted a stand of Mullein to develop on this prairie style green roof, increasing the biodiversity value. <br>Photo credit: jchill

</gallery>

</gallery>

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.

===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==

{{:Green roofs: Performance}}

{{:Green roofs: Performance}}

==Incentives and Credits==

==Incentives and credits==

===In Ontario===

===In Ontario===

City of Toronto updated their 'Eco roof' incentive program in 2017 . It now includes grants for structural assessment and is available to non-profit organisations [http://www1.toronto.ca/wps/portal/contentonly?vgnextoid=e08354ae91cda510VgnVCM10000071d60f89RCRD].  

City of Toronto updated their 'Eco roof' incentive program in 2017 . It now includes grants for structural assessment and is available to non-profit organisations [http://www1.toronto.ca/wps/portal/contentonly?vgnextoid=e08354ae91cda510VgnVCM10000071d60f89RCRD].  

{{:LEED: Rainwater management}}

{{:LEED: Rainwater management}}

==External Links==

==External links==

*[https://www.greenroofs.org/ Green Roofs for Healthy Cities]

*[https://www.greenroofs.org/ Green Roofs for Healthy Cities]

===Proprietary Systems===

===Proprietary systems===

{{:disclaimer}}

{{:disclaimer}}

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

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