What is a Green Roof?

Green roofs grow vegetation to improve a roof’s performance and help manage water where it falls.  The vegetation protects the roof from direct sunlight, limiting problems resulting from expansion and contraction, like leaks and accidental punctures.  Exposure to UV rays is detrimental to the longevity of roof membranes; it's like leaving a lawn chair out in the sun. The plants on a green roof make it last longer.

A green roof manages water by absorbing it into the lightweight growing media (soil) and the plants.  The plants evapotranspire (release moisture back into the atmosphere) through their leaf systems.  The deeper the growing media, the more water the plants can manage. Green roofs are built as a system in layers that include plants, special lightweight soil, and watertight membranes.  Usually installed on flat or low-sloped roofs, green roofs can be built either in trays or right on the roof. 

What are the Benefits of Green Roofs?

• Help protect our streams and Lake Michigan from pollution by reducing stormwater runoff

• Significantly longer roof lifespan

• Energy savings through added insulation

• Improved air quality

• Potentially usable green space

For questions on how to get started on your own green roof, contact the Fresh Coast Resource Center.