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

The HydroSpacer 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.

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 water accumulated in the lower area of the ”HydroSpacer HS 170” remains on the roof and is therefore available to the plants for a longer period of time. When it rains, the upper area will fill temporarily. This water then drains off through the retention run-off limiter at a slower rate.

The highlight of the “HydroSpacer HS 170” is its covering of a highly absorbent fleece. Once water begins to accumulate in the spacers, the fleece absorbs it at the contact surfaces, draws it upwards in a capillary action and subsequently distributes it to the overlying substrate layer. The plant roots in that area will take up just as much water as they need at any given time – it is specifically this function that comes closest to natural conditions.

System build-up

Notes: 

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