Green Roof Types
Extensive green roofs
Extensive green roofs have shallow (typically 7–10cm) soils. They support sedums, moss, herbs and grasses and other vegetation where low or no maintenance is required. They are the lightest type of green roof. Extensive green roofs provide attractive protection to the waterproof membrane and significantly reduce water run-off. When the green roof is completed inspection once or twice per year shall be provided. Regular fertilisation once per year, in fall or early spring, is required to ensure proper growth and success.The irrigation system is not needed, unless there are extremely long periods of dry weather conditions. Regular access to the extensive green roof is not required.
Intensive green roofs
Intensive green roofs have a deeper soil layer (15cm upwards) and a wider variety of plant types can be grown, from lawns to ornamental bushes and semi mature trees. The type of planting will determine the depth of soil required, the need for an irrigation system and the level of maintenance. Regular roof access is normally provided on this type of green roof, therefore paved areas, walls and even water features are incorporated in the design.
|Vegetation||Sedum, grass, herbs||Grass, ornamental bushes, trees|
|Irrigation||Mostly not||Always necessary|
|Load capacity roof||Most normally sufficient||Requires extra strong roof structure|
|Maintenance||Very low||Comparable with a normal garden|
|Roof pitch||Up to 45°||Flat or in terraces|