As big Canadian cities grapple with climate change, green roofs are catching carbon, shielding buildings from sunlight and moderating temperatures. Equally important for Halifax, which averages more than 1.35 metres of rain per year, is how green roofs reduce flooding by absorbing storm water and filtering runoff into sewers.
According to Halifax’s Ecology Action Centre (EAC), by 2009, Halifax Regional Municipality had more than 50 green roofs. More recently, specialized landscapers and ecologists have recommended simpler roof layering and resilient native plants as recipes for successful green roofs. Sue Sirrs, founder of Outside! Landscape Architects, says that many green roof companies apply numerous layers and, in the process, make rooftops “overdone,” heavy to support and expensive.
Working with a crew from Denmark’s Faroe Islands on a green roof for a Newfoundland home, Sirrs learned about the Danes’ method of anchoring sod with fishnet and rocks. Get daily news from Canada's National Observer Email * “They had a good laugh at all the crazy things that we do here with all the layers of green roofs,” she said. “[Theirs are] very applicable to our climate here too, simple to maintain, low cost to install, and easy to fix if there’s a heavy wind and the sod is pulled off the roof.
” In terms of design, the gaps in the netting allow the inner sod layer to nourish the exposed outer layer. Sirrs’ team has now built similar sod green roofs in Halifax. She .
