In the first of our special products sections, Specifier gets a bird's eye view of the best new roofing systems and how they've been applied – including Nicholas Grimshaw & Partners' record-breaking Frankfurt trade fair roof, and how Velux uses its own windows.
Steeling the show
Spanning an astonishing 165 m, the roof to the new hall of the Frankfurt trade fair sets a record for column-free spans. In the competition-winning design by British architect Nicholas Grimshaw & Partners and structural engineer Arup, the roof is a complex, curved folded plate, supported on giant arched trusses of tubular steel. The roof deck is a stressed skin made up of trapezoidal sandwich panels. Some 60 different panel types, typically measuring 8 m × 3 m, were prefabricated on site and bolted at each corner to flanges welded to the steel trusses. Set within a subframe of steel angles, each sandwich panel consists of profiled steel decking and a ceiling of corrugated perforated aluminium, with mineral wool insulation and a vapour barrier in the intermediate cavity. The roof finish is Kalzip-profiled standing-aluminium sheeting, which was delivered preformed to fit the roof curvatures.