These roofs differ from each other in the thickness of the structure its weight and the amount of maintenance that the plants require.
Green roof thickness.
Intensive to describe green roofs that are thick enough.
The nominal thickness of a green roof is the approximate total height of the soil and drainage components that constitute the green roof system excluding the roof structure insulation waterproofing and plants.
It is common practice to use the term extensive to describe green roofs that are very thin and will only support hardy drought resistant vegetation such as sedums herbs and perennials.
Green roofs can help reduce energy costs for a building by acting as another layer of insulation between the inside and outside of the roof.
Roughly speaking extensive green roofs have a thickness of between 4 and 15 cm and a weight of between 30 and 220 kg m2.
This is most noticeable in intensive green roofs since there is a thicker and more consistent layer of soil which provides a higher insulating value.
Also the green roof drainage layer material is made to be sturdy and strong so that piercing can be limited and that the integrity of the entire program can be retained with ease.