Green Roof - Extensive
Also known as living roofs, green roofs are a continuous layer of vegetation that is installed on a flat or slightly sloped roof surface.
Extensive green roofs are made up of a shallow layer of soil and plants, 1.5-6 inches in depth, laid over a drainage layer, waterproofing membrane and insulation. They support growth of smaller plants in the grass and sedum families and are more common on smaller residential buildings in areas where people seldom walk.
Green roofs may require additional structural support, and so it is advisable to conduct a structural assessment before installation.</p><p>While an extensive green roof does not require a lot of maintenance, occasionally, it may need to be weeded, fertilized, or watered, depending on the plants chosen.
Through the evaporation cycle, green roofs can help cool a city during hot summer months, reducing the heat island effect. As well, they add insulation value to a rooftop and decrease the exposure of waterproofing membranes to the atmosphere, reducing wear from temperature fluctuations and ultra-violet radiation and adding years to the life of a roof.
Green roofs have been used for thousands of years, both for insulation and water proofing and to create beautiful spaces such as the Hanging Gardens of Babylon!