A green roof also known as living roof or Eco-roofs or vegetated roofs, or VCWH (Horizontal Vegetated Complex Walls) is a roof of a building that is fully or partially covered with vegetation plants and a growing medium, planted over a waterproofing layer of the roof. On these roofs, some additional layers are added such as a root barrier and drainage and irrigation systems. Here the word “green” refers to environmentalism and not the color green with any roof tiles.
Remember that growing of plants in pots or containers are not termed as green roofs and are different from the green roofs.
There are many advantages of having green roofs on any buildings that ranges from houses to industrial complex centers. It absorbs rainwater, provides insulation, creates a habitat of wildlife, creates peaceful retreats for people and animals, provides shade, and helps in reducing air temperatures as well as it helps in mitigating the heat island effect. Even in hot summer days, green roofs temperature is cooler than the surrounding air temperature whereas the conventional rooftop can be higher temperature. Another advantage of green roofs is that it can be used to produce our natural vegetation.
There are two types of green roofs:
1) Intensive roofs
2) Extensive roofs
Intensive roofs are thicker and can support a wide variety of plants but are heavier and require more maintenance whereas extensive roofs are lighter and can be used to grow lighter plants.
The important thing while constructing the green roof is it should be like any roof, accommodate drainage and protect the building from the elements with a waterproof membrane. It should also provide a facility of growing area and potentially provide support, irrigation and root protection barriers while staying as light as possible.