Green Roofs

Roof that are not well insulated can suffer from problems such as the formation of ice dams around the overhanging eaves in cold weather, causing water from melted snow on uper parts of the roof to penetrate the roofing material.
• Drainage
The primary job of most roofs is to keep out water. The large area of a roof repels a lot of water, which must be directed in some suitable way, so that it does not cause damage or inconvenience.
Flat roof of adobe dwellings generally have a very slight slope. In a Middle Eastern country, where the roof may be used for recreation, it is often walled, and drainage holes must be provided to stop water from pooling and seeping through the porous roofing material.