The Green roof system is an extension of the existing roof which involves, at a minimum, high quality water-proofing, root repellent system, drainage system, filter cloth, a lightweight growing medium, and plants.
Green roof systems may be modular, with drainage layers, filter cloth, growing media, and plants already prepared in movable, often interlocking grids, or loose laid/built-up whereby each component of the system may be installed separately. Green roof development involves the creation of "contained" green space on top of a human-made structure. This green space could be below, at, or above grade, but in all cases it exists separate from the ground.
Green roofs can provide a wide benefits and have been successfully installed in countries around the world.
Green Roof Benefits
1. Water Diversion
2. Stormwater Manage ment
3. Improves air quality
4. Energy Efficiency
5. Fire Retardation
6. Noice Reduction
7. Increase Biodiversity
8. Improved health & well-being
Disadvantage of green roofs
1. The initial cost of installing a green roof can be double that of a normal roof.
2. They attract pest insects which could easily infiltrate a residential building through open windows.
3. The additional mass of the soil substrate and retained water places a large strain on the structural support of a building. This weight can not be supported by all buildings.
How much Green Roof cost?
The cost of a green roof depends on the type and factors such as the depth of growing medium, selected plants, size of installation, use of irrigation, and whether they are to be accessible on inaccessible - intensive, semi-intensive, or extensive.