As it was mentioned in previous modules, green roofs are internationally placed in two main types:
Of course, there are some cross overs between the categories.
The key characteristics of intensive and extensive roofs are summarized further on.
As they are lightweight, they are easier and less costly to install. In general, they do not require irrigation although some irrigation may be required initially.
Sedum mats have a base layer of polyester, hessian, or porous polythene, depending on the supplier. A 20 mm layer of growing medium is laid and sedum seeds or cuttings are spread across it.
Substrate based green roofs generally have 80 mm of substrate. The substrate sits on the filter sheet, drainage layer and protection layer. The vegetation layer consists of sedums and wildflowers.
Brown roofs for biodiversity: the original concept was to use recycled brick and concrete from a local recycling plant. Over the years, the brown roof idea developed into the green roof designed for biodiversity. Roof substrates have about 20% organic material and only native species are used for this purpose. Find out more.
Introduction on how to build a self-designed green roof:
Here are some instructions and practical examples on how to create a green roof: