The St Katharina senior residence in Heppenheim is different from many retirement homes: right in the entre of the city one can find the well-earned peace to think things over, to have a chat outside or to have a little nap in the spring sun – right on the roof. Since here, old-age citizens have 1,200 sqm of grassed area along with tulips, narcissi and grape-vine, a true oasis in the city including a 250 sqm conservatory.
Bitumen panels for a secure waterproofing
The planned roof garden was a special challenge during construction work, since it was supposed to have a long-lasting and secure proofing along with an extensive and intense vegetation. For financial reasons the general contractor had initially planned to have the roof proofed with PVC. This was something the material supplier did not agree with. ”A single-layer 1.5 mm thick PVC proofing would have caused leaks. The reason was the high strain due to applying vegetation with substrate“, explains Ulrich Menges from the VEDAG GmbH, specialised in roof proofings. “Apart from that, working with quipment such as shovelsand racks would have been too risky for the proofing’s security.“
The roofer, Körber GmbH from Mannheim, as well as the VEDAG experts made convincing efforts and were thus able to implement an alternative of higher quality. ”A double-layer bitumen proofing
simply provides the required security beneath the vegetation “, says Menges. ”The elastomer bitumen panels were welded together in a holohedrally manner. I think we can act on the assumption that this proofing is going to last for at least 20 or 25 years without any problems.“