Drainage Board is molded by PP with high strength, the compressive ... used in water drainage under earth, wall drainage and other large area draining water.FeaturesMaterial: HDPE, PPSpecification: Drainage Board 40*40cm; Drainage Cage 40*40* ... drainage in building foundation, basement, roof, and lagging. Virescence use:used in Garage roof Virescence, roof garden, court and bathhouse, etc Drainage Board ...