Sika Drainage Mat Grs 4' X 50' Roll

4' x 50' x 1" Roll, Drainage Mat

Sika® Drainage Mat GRS for vegetated roof assemblies consists of an impermeable dimpled polystyrene drainage core. The core is perforated, then bonded to a root resistant non-woven polypropylene filter fabric on the top side and nonwoven polypropylene membrane protection fabric on the bottom side. The filter fabric helps prevent roots from affecting the efficiency of the drainage/aeration layer as well as retaining soil or other fine particles from being washed away and allows water to pass into the drainage core. The bottom protection fabric provides cushioning for the waterproofing membrane. The core is installed dimpled side down to allow water retention within the cups. Excess water is collected and conveyed to a proper collection system, helping to control drainage flow.