... used as part of a waterproofing system, Drainage & Venting Layers acts as both a drainage layer reducing water pressure ... the waterproofing membrane, ideal for buried structures.Drainage & Venting Layers can also be used as a drainage and gas ... cost effective replacement to granular stone behind retaining walls.ProjectsGas venting,Retaining walls, reservoirs, landfill, highways, block paving, buried ...