Due to the sloping construction, we had to take into account a lower load-bearing capacity of the roof. Because of the large slope of the roof, we used georasters, suitable for holding vegetation in place. These are elements that we could attach to each other to create a continuous network of collection grids.

A protective and water-adsorption fleece was applied under these grids. This to protect the roof waterproofing and also retain additional water, about 10l/m2. Substrate was blown into the grids: a lightweight substrate consisting of peat, lava, bims and argex.

After levelling and pressure-tightening the substrate, we could start installing the pre-cultivated sedum vegetation mats. To ensure that the mats could not slide down, we installed impact plugs between the georasters. We could push these plugs through the sedum mats and this way the sedum mat stayed nicely in place.