A particular challenge was the approx. 18-metre-high support masts through which an existing drainage line was already routed. As these masts could not simply be opened, the downpipes—the “engine” of a siphonic system—had to remain in place, and the hydraulic balancing was carried out solely via the collector and individual connection lines. This required a very high level of engineering effort and many years of siphonic drainage experience. Many of the 166 roof outlets in total—Spin for gravity drainage and Jet for siphonic drainage—were specifically designed and custom-fabricated for the project to match the conditions and the roof membrane. A large number of the 800+ fittings and transitions were also special parts designed for this project. In addition, 1,800 axial thrust restraints and 1,800 gaskets were used. At the customer’s request, many components—such as bends, branches, the visible lower section of the roof outlets, over 1,000 metres of GM-X composite pipe, and even gaskets—were manufactured in white.

Nearly 900 metres of compound pipe in sizes DN 80 to DN 200 were also fitted with trace heating, ensuring safe roof drainage operation even in freezing conditions. A further challenge was the logistics of handling the white components so that all could be installed without damage. Deliveries were made by pipe network—that is, each complete set of outlets, fittings and pipes belonging to one section was delivered directly to site.

The result speaks for itself, and ACO Haustechnik proved to be a reliable partner for complex, customer-optimised roof drainage systems.