System Build-up “Sponge City Roof” – Temporary Retention, Large Water Reservoir and Increased Evaporation 

The HydroSpacer® HS 170 allows Zinco to come closer to its goal of bringing the water balance of a developed area closer to that of an undeveloped area. The basic idea is to have as much storage space as possible beneath the substrate and plant level. On the one hand this is to efficiently absorb heavy rainfall events and on the other hand to store water so that it is available to the plants. The accumulated water will supply the plants during dry periods, and in doing so will maintain their evaporation capacity over a long period of time. The vegetation will develop more dynamically and overall with greater biodiversity, depending on the natural distribution of precipitation.

The system build-up “Sponge City Roof” is intended for use on flat roofs that are professionally waterproofed.

How does the HydroSpacer® HS 170 work?

The HydroSpacer® HS 170 can store up to 160 l/m² of water. Up to 11 l/m² of this can be provided to the plants each day.

The storage space can be divided into a longer-term accumulation of water available to the plants in the lower area and an additional temporary retention area. Excess stormwater is drained off in a regulated and time-controlled manner via the retention run-off limiter. In this way, the HydroSpacer® elements carry out the tasks of ensuring water reserves, being prepared for heavy rainfall and providing a load-bearing sub-construction.  

The components Capistrips® and Capifleece® CF 200 are the technical centrepiece of the system. Four Capistrips® per HydroSpacer® are drawn into the lower storage space. These durable, rot-resistant fleece strips absorb the water and transport it upwards to the top of the element. At the top, the fully fitted Capifleece® CF 200 then distributes the water horizontally and is the contact with the overlying substrate layer. With that, vertical transport and horizontal distribution combine to create a synchronised system – driven solely by the power of capillary action..

System build-up

Notes: 

* The weight values stated above are considered to be exclusive of vegetation, see Info Sheet "Green Roof Ballast".