Green Roofs Catching On Fast

Green Roofs Catching On Fast BUILDINGS Miscellaneous 32-1-44 Why install 15-year shingles when you can grow a green roof that will last a lifetime? The idea of laying down earth on a roof and planting drought and cold tolerant plants is catching on fast across North America. "You can walk into any large hardware store in Norway or other northern European cities and find all the components you need for a green roof," says Elisabeth Ryan, president, Kestrel Design Group. Ryan's Minnesota-based company has designed and installed green roofs on large commercial and municipal buildings like the recently completed Minneapolis Library. She gets many inquiries from livestock owners interested in the concept. "Green roofs keep buildings warmer in the winter and cooler in the summer," she explains. "The plants that grow on them evapotranspire, cooling the area underneath. That's why they are so valuable to city buildings." How much do they help? One study of the Minneapolis Library roof recorded 90¦ highs while a traditional commercial building roof registered 170¦. In studies of other buildings, sound levels have been reduced as much as 40 decibels with the addition of a green roof. Another advantage to green roofs is they absorb light rainfalls. This is important for cities wanting to reduce runoff. Heavy duty plastic and rubber membranes are laid down over the roof surface. A felt pad is often laid over that to hold the soil media in place. Plants, such as sedum, that thrive on thinner soils and minimal nutrients, are added. Ryan used a variety of native plants on the library roof to provide habitat for birds, bees and other insects. Ryan has also used rolls of special sod that contain desirable plants. For pitched roofs with more than a 3-ft. in 12-ft. incline, she advises using a system of baffles to keep soil media and plants from shifting. Linda Velazquez, publisher of Greenroofs.com, an industry Web resource, says green roof popularity is skyrocketing. She estimates there are around 1,000 projects covering some 9 million sq. ft. currently underway in the U.S. Canada is a leader in adoption of green roofs with Toronto, Ontario home to Green Roofs for Healthy Cities, the industry association for the U.S. and Canada. Ryan advises people interested in installing a green roof to contact Greenroofs.com for information. The cost of a green roof is $8 to $10 per sq. ft. compared to $2 to $3 per sq. ft. for 15-year asphalt shingles. But the green roof should last at least three times longer and provide heating and cooling benefits. A 50-year-old green roof in London was recently taken down and the underlying membrane was in perfect condition. Contact: FARM SHOW Followup, Greenroofs.com, LLC. 3449 Lakewind Way, Alpharetta, Georgia 30005 (ph 770 772-7334; toll free and fax 888 477-1326; www.greenroofs.com) or contact Green Roofs for Healthy Cities, 406 King Street East, Toronto, Ontario, Canada M5A 1L4 (ph 416 971-4494; fax 416 971-9844; www.greenroofs.org).

To read the rest of this story, download this issue below or click here to register with your account number.