Green Roof Solutions offers many different drainage layer options, depending on system goals regarding water retention. The most critical role of the drainage layer is to provide an adequate flow of water off the roof during and after a rain event. The design of the different drainage layers allows for a portion of the stormwater to be retained above where the water is allowed to flow freely off of the roof. The systems are designed to ensure that stormwater can be used by plants for longer periods of time without oversaturation of the system. This promotes plant growth, avoids anaerobic soil conditions, and keeps retained water from pooling on the roof.
GRS drainage products typically fit into a green roof system above GRS Root Barrier and below GRS filter fabric. Depending on regional precipitation rates and the water retention goals for your specific project, Green Roof Solutions has a full range of products to meet your needs.