What is it used for?
Traditional roofs tend to re-emit the sun’s energy that they have absorbed during the day, contributing to the well-known problem of heat islands in our cities.
With green roofs, buildings are better insulated and use less energy. As a result, the issue of heat islands is alleviated. In addition, green roofs:
- reduce the quantity of rainwater running into our sewers;
- protect roofs and increase their life span;
- do not produce any waste (asphalt, gravel, etc.);
- improve air quality.
Green roofs can also have recreational and aesthetic functions and provide a home for greater biodiversity. As a bonus, they can be used to grow edible plants!
How is it made?
Green roofs can be installed over traditional roofing materials or underground load-bearing structures (like parking garages). They comprise several distinct layers:
- a layer of vegetation;
- a growing medium; › a drainage and water retention system;
- a barrier to prevent roots from piercing the roof’s waterproof membrane.
There are extensive green roofs, which are lighter, and intensive green roofs, which are heavier. The latter have a greater variety of uses (for example, it is possible to walk on them) but require a stronger support structure.