This is where green roofs come into play, providing additional green space in densely developed urban areas. Each green roof stores a certain quantity of stormwater and then allows it to run-off in a time delay or to evaporate on the roof. The New Stormwater Management Roof from ZinCo expands this retention effect and in so doing effectively balances out precipitation peaks.
Each individual green roof contributes to the alleviation of the public sewerage system. For example, a standard extensive green roof stores between 20 and 40 l/m² of water in its green roof build up and an intensive green roof stores between 50 and 100 l/m², in some cases even more. With regard to the risk of flooding, a green roof should store as much water as possible. Otherwise, the excess water available to plants can result in a transformation of the vegetation and therefore to a requirement for increased maintenance and care or even to water logging and root rot. For this reason, ZinCo has developed the new Stormwater Management Roof in two separate parts, the retention volume and the actual green roof build-up.
This is how it works
In the new ZinCo stormwater management roof an element referred to as a “spacer” is used beneath the green roof build-up. The height of the spacer can be varied, as required. For example, a 10 cm high spacer allows for the storage of about 80 l/m² of rain, based on a zero pitch flat roof with the required load-bearing capacity. The retention capacity of the green roof can therefore be increased by a multiple. During a pre-defined period of time (between 24 hours and a number of days), the retained stormwater runs off slowly through a throttle element inserted into the gully and on into the sewerage system. In order to ensure that these parts continue to work perfectly, the gully and the throttle element are located for their protection inside the inspection chamber, where the fine slits prevent foreign particles from being washed in.
The green roof build-up over the spacer contains all elements that are required for the green roof to function properly, for example, air-water household in the root area, drainage and water storage for the plants. An intensive green roof, naturally, requires a greater level of water than an extensive roof that has drought-resistant sedum plants. Each green roof build-up, is therefore, adapted to suit the relevant vegetation. Virtually all types of green roof and roof utilisation are possible, even pathways and driveways.
Developing the stormwater management roof in two parts allows for a lot of water to be stored regardless of the level of water required by the green roof itself and without any risk of vegetation transformation or water logging.
