Sponge City Roof
Temporary retention, large water reservoir and increased evaporation

The System Build-up combines the advantages of an insect-friendly, biodiverse extensive green roof with an additional water storage and a temporary retention volume with controlled-flow roof drain. This system build-up helps to bring the water balance of built-up areas closer to that of undeveloped areas. The lower part of the accumulation volume is available to the plants via the highly capillary fleece and thus ensures increased evaporation. In the upper part of the water accumulation volume stormwater is built up to a predetermined depth and drains at a desired rate.
The vegetation develops dynamically depending on the precipitation distribution throughout the year.
A roof surface without inclination is a precondition for this System Build-up. The accumulated water shall be drained during the winter months and restored at the beginning of the vegetation period.
System build-up
Notes:
* The weight values stated above are considered to be exclusive of vegetation, see Info Sheet "Green Roof Ballast".
Technical Data | |
---|---|
Build-up height | ≥ 250 mm |
Weight, saturated | ≥ 280 kg/m² |
Water retention capacity | ≥ 193 l/m² |