Green roof layers typically consist of:
- Waterproofing membrane over the roof deck – this is the base layer and it must be reliable
- Protective, insulating layers
- Root barrier
- Drainage layers consisting of gravel, stones or other suitable medium
- Planting layers – including soil and planting
The top layers can also include specimen plants or trees, walkways, terracing and seating areas in an intensive green roof design (subject to load bearing capacity).