The double-layer dimpled membrane is a water-storing drainage membrane and is regarded as an ideal solution for extensive and intensive roof greening

Advantages:

• Compared to normal dimpled membranes, geomembrane 20-150 offers many times the drainage and water storage capacity and assumes the function of a protective, filter, seepage and water storage layer in green roofs. The 20 mm dimples have a water storage capacity of approx. 6 L/m². The 20 mm dimpled membrane offers an unusually high drainage capacity of i = 1.00; approx. 8.54 l/s·m. It can therefore also be used for very large drainage lengths and/or very low roof slopes. The plant substrate can be applied directly as the geotextile is already integrated. This saves an additional work step
• Thanks to the perforation, the water-storing drainage membrane is permeable and can also be used for inverted roofs. This prevents a film of water from forming on the inverted roof insulation. The geotextile should be removed from walkable areas without vegetation. The base layer and the bedding material can then be applied directly on the dimpled membrane without changing the material, and then the pavement or slab covering can be laid on top of it

Installation:

• The waterproofed surface must thoroughly cleaned so that no damage can occur to the sealing after laying the drainage membrane. The green roof waterproofing must be root-resistant
• Lay a geotextile as a protective and separating layer with at least 300 g/m² on the waterproofing
• Drainage geomembrane 20-150 is laid horizontally with the dimples to the surface by rolling it out, with the filter-stable geotextile facing upwards
• The dimpled membranes are overlapped by 10 cm (two rows of dimples)
• The dimpled membrane can be cut to the required length with a knife, but do not damage the waterproofing
• If the laid membranes have to be extended, the connecting membrane is pushed under at least 20 cm from below
• The horizontal overlaps must be shingle-like in the direction of the water flow. On rising components, the dimpled membrane should be raised at least 10 cm (2 rows of dimples)
• The dimpled membranes are laid step by step
• The plant substrate can then be applied directly