Roof-gardens

is a geocomposite drainage and water attenuation layer comprising a perforated cuspated HDPE (High Density Polyethylene) core with a UV-stabilised geotextile filter thermally bonded on the upper, flat side. 

It is primarily intended for use under thin soil layers where the plant roots can reach down to the water in the core reservoirs. 

The core is perforated to allow excess rainwater to flow into the underside and away through the TerraDrain to the outlets. The textile is optimised for drainage performance. Its major application is in extensive roof garden drainage where TerraDrain provides a lightweight drainage layer and water reservoir to sustain plant growth. 

TerraDrain makes extensive use of recycled polymers in its construction.