Green roof drainage layer
Our Drainage Layer product, Roofdrain, is ideal for extensive green roofs as it provides a lightweight drainage layer with a water reservoir to sustain plant growth.
Roofdrain attenuates rainfall making it an important element of a SUDs system. Roofdrain consists of a perforated cuspated recycled HDPE (high density polyethylene) core with selected geotextiles thermally bonded on each side. The core acts as a water reservoir holding 4.5 – 5.5 litres per square metre for plants to access in dry periods. The core is perforated to allow excess rainwater to flow into the underside and away to drainage outlets.
The upper geotextile acts as a filter, preventing any fine particles from the substrate blocking the drainage layer. The upper geotextile layer also has a ‘zero’ breakthrough head to prevent over-saturation of the substrate.
The lower geotextile has two key functions: it offers additional protection to the waterproof membrane and acts as an extra moisture retentive layer, holding an additional 1.0 litres per square metre. This further enhances the water holding capacity of the system and slows the rate of run-off.
Features & benefits
Acts as water reservoir holding 4.5 -5.5 litres
Drainage filtering system
Additional protection to waterproof membranes
Manufactured from 95% recycled materials