Study underway on Dentistry Bldg.
By Lawrence McMahen
The latest thing in Saskatchewan roofs may be a high-tech version of the “soddy” huts of 100 years ago with their insulating rooftop layers of wild Prairie sod.
In a unique joint project, the U of S Facilities Management Division (FMD) has teamed up with a Geography professor and student to create the first “green roof” on any institutional building in the province.
A series of 16 shallow 10-ft-square planter boxes now adorn the rooftop of the University’s Dentistry Building – and the high-flying vegetation is intended to be a three-year experiment to test the effects and feasibility of green roofs on the Prairies. It should also discover which plants can survive in the harsh rooftop climate.
FMD Sustainability Co-ordinator Margret Asmuss says green roofs are becoming popular in Europe and the United States because they reduce harm to the environment and can improve quality of life and even save money.
Geography Professor Bill Archibold says this project follows a study by a student last year on plants that grow randomly on campus rooftops.
Archibold and Asmuss say the academic inquiry into the science of green roofs fitted nicely this year with FMD’s desire to look at ways to pursue more environmentally friendly practices at the U of S.
The result was that honours Geography undergraduate student Cimberly Kneller took on the assignment of the green roof project. For the past summer she was paid by FMD and a provincial Green Team employment program to work with Archibold and Asmuss and make the green roof a reality. At the same time, she made the project the subject of her undergraduate research project.
Kneller says the Dentistry roof was chosen because it’s strong enough to support the weight of the vegetation project, since it was built to hold up a future additional storey.
Early in the summer, Kneller organized construction of the 16 rooftop garden plots. She used a commercially available kit to outfit each planter box with an underlying membrane, a drainage system, soil and a growing medium.
She planted 23 species of plants including silver brocade, blue fescue grass, creeping phlox, three varieties of thyme, western wheat grass, and arabis. After some initial watering early on, just to get the plants established, Kneller has left the plants to fend for themselves – since the goal is to see what vegetation can be self-sustaining for a true Prairie green roof.
Archibold explains there are a series of high-tech sensors set up above and around the plots. They measure and record precipitation, wind-speed, air temperature, humidity, and the inflow and outflow of radiant energy from the planted areas.
“We hope to measure the data for two to three years”, to gain a good understanding of how the plants do in Saskatchewan summers and winters, Archibold says.
Asmuss says green roofs have a number of beneficial effects. They counteract the ‘heat island’ effect of largely paved urban areas, they keep buildings cool in summer and warm in winter, they extend the life of roofs by up to 25 years thus saving maintenance costs, and they provide wildlife habitat.
Asmuss is excited not only by the environmental possibilities, but also by fact that this project is a great example of an academic department and a “hands-on” unit like FMD working together on a project that is relevant to both.
She hopes to forge more joint projects with other departments on campus to pursue her goal of increasing sustainability and environmental responsibility at the University.