... and Roof Graden , High compressive strength. Together with geotextile, Drainage, waterproof, breathe freely, protect wet.The advantage of Drain cell1 ... . High compressive strength ,Light weight , fast Drainage , breathe,anti-aging and easy to transport . 2. The ... and layer is completed, began to shop installs drainage plate. The drainage slope requirements 2‰~5‰2. Green roof can ...