A Green covering shelter is a very light type of green roof. This type of greenroof has a very light and thin substrate to avoid that the roof has a lot of weight. The vegetation should to be small.

A green covering shelter is built with:

• Gravel on the perimeter, to facilitate the drainage of water.
• A waterproof layer. The material must to be resistant to roots: PVC,EPDM…
• A separating layer. This layer must to protect the waterproof layer. It isusually use geotextile sheets.
• Hydroponic substrate. Special rock wool panels for vegetation growth. This type of substrate is lighter than the granular substrates.
• Vegetation. The best vegetation for this NBS are different species ofsedum. This type needs little water and it has a low maintenance.
• Irrigation system. Drip irrigation pipes that soak the substrate.

It is important to know the strength of the structure before installing this NBS,because is necessary to know if the structure is able to support this type of roof.