At the Old Spinning Mill

Roof construction as a combination of membrane surfaces and a mesh of 2-ply membrane belts
Quest Immobilien
Behnisch Architekten

Kolbermoor near Rosenheim in Bavaria dates back to the construction of a cotton mill in the 19th century. The production was stopped in the 1990s. And a new urban district has been developed on the factory site with industrial character. The open space accommodates exhibitions, concerts and the central meeting point, the »Alte Spinnerei« (old cotton mill). The area is enclosed by a membrane surface of PTFE-coated glass fibre fabric which merges to a grid of 10 cm-wide membrane belts. It is rather a delicate sculpture than a roof, which is connecting the ensemble across the channel. The grid construction which is subjected to tension consists of 100 mm-wide 2-ply fused membrane belts held by structurally minimised stainless steel clamps. Overlapping and twisted at the intersection points they are connected by a central bolt to be able to transmit the differential forces. The pylons made of glue-laminated timber have a length of 6.2 and 16.5m. These are hinged columns with a ball-and-socket joint at the root which transfer the load via micro-piles and reinforced concrete pile heads into the bedrock. Welded membrane beads at the edges of the roof direct the rainwater to the two low points. From there it runs into the garden and via a pocket in the membrane into the downpipe at the building.