The ND 4+1h Drainage system is the ideal under layer for an extensive green roof. This multifunctional, CE-marked drainage system with high compressive strength protects the vegetation from water stagnation, while at the same time storing water for dry periods in the built-in water reservoir. In addition, the ND 4+1h Drainage System protects the waterproofing membrane from a build-up of hydrostatic pressure and mechanical loads, both during and after installation.

• Dimensions approx.: 30 m x 1.25 m
• Packaging approx.: 37.5 m², roll
• Weight approx.: 1,017g/m²
• Build-up height approx.: 17 mm
• Compressive strength approx.: 450 kPa
• Material dimpled sheet: recycled, high impact polystyrene (HIPS)
• Material geotextile filter: polypropylene (PP)
• Material vapour-permeable geotextile: polypropylene (PP) and propyethylene (PE)
• Perforations /m²: approx. 1,540, ? 6.3 mm
• Water reservoir: approx. 4.3 l/m²
• Drainage capacity i = 1 (20 kPa): 7.86 l/(s.m)
• Drainage capacity 2 % fall (20 kPa): 0.96 l/(s.m)
• CE: hEN EN 13252