401 Richmond's Extensive Green Roof

In September 2005, another 2,600 square feet of extensive green roof was designed and installed on the pre-existing roof membrane and ballast at the rear portion over the third floor of the Richmond building. An extensive green roof was selected for this location due to its light weight, ease of staging, the vantage point for tenants on the fourth floor, and general proximity to the existing garden roof area. In addition, two small 100 square foot green roofs were also installed on the roofs of existing heritage skylights. These smaller prototypes add an interesting dimension on sizing of green roofs and are more accessible for public viewing and inspection of the technology.

An extensive green roof on the Richmond building supports a number of structural, environmental and building benefits including:

• roof membrane protection (existing roof membrane is > 20 years);
• respects structural load requirements of the heritage building (< 68 psf live load);
• provides energy benefits for tenants in summer;
• attracts invertebrates and birds;
• reduces surfaces temperatures and thereby urban heat island;
• provides stormwater runoff improvements;
• reduces air pollution – particularly smog precursor; and,
• improves visual aesthetics for visitors and tenants.

The green roof product on the Richmond roof is known as a Xero Flor roof. It is a light-weight vegetated product that is grown in a pre-seeded vegetated mat system on light sandy soil near Woodstock, Ontario. These vegetated mats can be cut to size and installed easily over a retrofit roof. Xero-Flor originated in Germany in the early 1970’s and has been available across Canada and the United States over the last several years. The vegetated mat is made up of a fleece mat, a coiled plastic mattress where roots and planting media adhere, and the plants are predominately sedum species. Other Xero Flor roof applications include condominium applications in the City of Toronto, the Ford Motor plant at Deerborn, Michigan, the Honda Motor plant in Aliston, Ontario and more recently, the City of Waterloo City Hall roof. Xero Flor promotes this light-weight sedum-based product for residential roofs and industrial commercial applications as well.

401 Richmond is pleased to feature this green technology as another means of acting locally to promote urban revitalization (environmental and social), tenant enjoyment and heritage building conservation. The Management and staff will be monitoring the green roof for plant survivability, environmental benefits, maintenance needs, species migration and other features over time.

If you would like more information on this product please visit: www.xeroflor.ca