The drainage layer is a critical component of a green roof system, responsible for facilitating water runoff, providing aeration to plant roots, and protecting the waterproofing membrane. A high-quality drainage layer prevents soil oversaturation, which can otherwise increase the structural load on the roof and compromise its integrity.
: ~$489 at BlueStone Supply or ~$422 at Best Materials . green roof drainage layer buy
: Includes two filter layers (root-resistant and membrane-protective) and is made from 100% recycled filter fabric. Enkadrain 3811R Green Roof Drainage Layer The drainage layer is a critical component of
: A more cost-effective and lighter alternative to the standard GRS, designed for projects with lower water retention requirements (~0.042 gal/sq. ft.). : ~$380 at BlueStone Supply . Types of Drainage Layers : ~$380 at BlueStone Supply
: A high-retention system specifically designed for green roofs. It features an inverted dimpled core that retains approximately 1.1 gallons of water per 10 square feet.
: Applications requiring continuous discharge under heavy compressive loads, such as rooftop gardens or permeable paver bases. J-Drain GRS50
When selecting a layer, consider which technology best fits your project’s hydrological needs: Overview for green roofs - Minnesota Stormwater Manual