Green Roof Thickness

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 roof thickness.

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. The green roof drainage layer thickness makes sure that nothing can go wrong below offering a solid and effective guard. 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. Roughly speaking extensive green roofs have a thickness of between 4 and 15 cm and a weight of between 30 and 220 kg m2.

These roofs differ from each other in the thickness of the structure its weight and the amount of maintenance that the plants require. 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. Smaller thickness of the system will not compromise the performance due to the fact that urbanscape green roll can hold up to 3 4 times more water per its volume than other green roof substrates.