Green Roof for the Garden Patch
We recently installed a green roof on our Garden Patch storage shed. The roof was designed and installed by Michael Molaro of Higher Ground Horticulture. We love it! As our garden begins to adopt more demonstration and education elements, we are thrilled with the aesthetic addition of a green roof. It's practical too! Green roofs on homes and sheds have numerous benefits, including storm-water management, air-quality improvement, improved urban biodiversity and the protection and extension of roof. At the Garden Patch, our metal storage container can reach an interior heat of 100 degrees F in the mid-day heat. With our newly installed green roof, we already notice reduced temperatures!
We asked Michael Molaro to answer a few quick questions about our project and green roofs in Saskatoon. Here's our conversation:
What is a green roof?
By definition it is “a contained vegetated space on top of a structure, above or below or at grade level”. A green roof is not always green and is sometimes referred to as a living roof. Depending on the design and vegetation and local climate, over time some plants can become more dominant resulting in changes to its appearance over time. Like any landscaped area there is some maintenance required, especially during the first couple of years.
What are the benefits of installing a green roof in Saskatoon?
Green roofs in our city can absorb most of the storm water that falls on them; act as a ‘biofilter’ for particulates (air pollution); help reduce hot urban temperatures; greatly extend the life of the roof membrane (reducing construction waste in the process); provide a space for urban agriculture; add to urban biodiversity and provide socially and aesthetically beneficial spaces.
Tell me a little bit about the green roof project at the Saskatoon Food Bank Garden Patch.
Brit MacDonald approached me this spring asking if one of their garden sheds might serve as a place for a green roof. After some research, I determined this flat roofed metal container could carry the load and adequately drain a green roof. Further refinements to the design allowed for a low-cost and relatively low-tech approach. The soil medium is primarily non-organic and includes components such as perlite, pumice, lava rock and some rubber crumb. Organic components include peat moss and compost.
The ‘engineered’ soil is almost 150mm deep with filter fabric and a drainage layer below it. The mix is relatively light compared to garden soil, but there is still about 1,000 pounds of it on the roof. The wood frame is insulated on the inside and the growing area is close to 70 square feet.
I want to thank Kevin Hall (SherCom Industries) Gift Marufu (UofS Grounds) and Brent Martian (480 Group) for their contributions to this project.
What does the future of green roofs in Saskatchewan look like?
Considering more mature markets in Calgary and Edmonton for instance, the future looks very ‘green’ indeed. However, civic-supported education, awareness, policy and programs have long proven to be a catalyst in major cities like Toronto, Portland and Calgary, to name but a few. Without these initiatives, we will continue to lag behind others cities – mainly due to lack of awareness by owners and what I would call a lack of familiarity and confidence within the design and building communities.
Michael Molaro is an accredited Green Roof Professional (GRP) and Principal of Higher Groundwork HortiCulture. In addition to fulfilling GRP training and examination, Michael has completed other related courses including Advanced Green Roof Maintenance, Introduction to Rooftop Urban Agriculture, Integrated Water Management for Buildings and Sites, and Green Infrastructure Projects, Performance and Policies. Prior to his many years at the University of Saskatchewan he worked in architectural practices in Edmonton Alberta and Saskatoon Saskatchewan.
During Michael's latter years on campus he developed and managed the Office of Sustainability where one of his passions became green roofs. He now wants to demonstrate to owners, design professionals and builders that green roofs can work well in our region and provide numerous benefits.
Find our more about green roofs in Saskatoon at Higher Groundwork Horticulture.