Green roof of a building is described as roof covered with vegetation partially or completely on growing medium soil etc. Green roof vegetation is planted over water proofing material which is laid on the top of RCC slab to protect roof from dampness or leakage. Additional layers also include a root barrier, drainage and irrigation systems. Green roofs are made by placing layers of water proofing treatment deliberately over the roof to support growing medium and vegetation is relatively new phenomenon.
Go green living-better for health, better for nature
(This Picture is Contributed by "Isha")
In some cases containers i.e. pots are placed with green plants on the roof but this is not really a green roof. Painting merely by green color on the top of roof does not refer to green roof. Sometimes the roof having green technology is termed as ‘green roof’ such as water pool with green water, solar panels. Green roof has great effect such as it keeps temperature down particularly in urban areas where building proportion is more greening of the roof which has high impact for maintaining good environment. Green roof improves environment specially city’s, mitigate and storm water problem.
Green roof construction takes 30 to 40 days’ time for development. It includes vegetations, growing medium, drainage; irrigation system, water-proof installation and roof access are installed one by one on the top of roof slab. Depending on the size of green roof and types of plants, vegetations may need one or two growing seasons to be fully grown. The maintenance in built-up system requires regular watering, weeding, cultivation for survival of green roof.
According to cutting-edge research, green roof are divided into four categories as mentioned belows:
• This system is simple and easy to install.
• In modular system the depth of soil ranges from 3 cm to 15 cm.
• Green roof and maintenance process is very easy.
• This system is light in weight and has 6 to 8 Kg. weight per square feet.
• Growing medium usually contains sand, peat, gravel, organic matter, crushed bricks and some soil.
• It can be installed at any time throughout the year as vegetation is available pre- planted.
• Modular system has overall success in green roof because survival rates of vegetation are higher.
Green Urban Nature- Demand of time
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Extensive green roof system is designed for their aesthetic and environmental benefits, which is not typically designed for walking on. This type of green roofing systems is planned with low growing plants such as mosses and succulents. This roof system is low in maintenance cost because it is not designed to be on regular basis.
The in extensive green roofing is comparable with roof garden and this is designed to access and therefore to be walked on larger shrubs and trees planted in this system. These require frequent maintenance. Extensive green roof system is typically used by local authorities or by public access organization which are opening their green roofs as a green space for people to visit.