The exhibition hall is 135m long and enclosed by two hyperbolic paraboloid roofs, rising to a central ridge 29m high. The roof structure consists of cranked trusses formed from straight tubular members, each truss set at a different angle to create the compound curve.
Off-the-shelf roofing products were used: a structural Plannja deck system; a vapour-control layer; 160mm glass fibre quilt insulation; and an aluminium standing-seam roof covering.
To create the overall curve of the building form, a series of fabricated channels were welded to the 273mm-diameter CHS top boom of each truss.
The channels were rotated to varying degrees to suit the orientation of the Plannja deck.
A 3mm-thick galvanised-steel seating tray was bolted to the top of each channel and secured with self-tapping screws.
The downstand edges of the two adjacent Plannja decks were fitted into the troughs of the seating trays and fixed to the flanges. Projecting halter clips were fixed to the Plannja deck through the vapourcontrol layer, followed by the insulation quilt and the aluminium standing-seam roof covering.
The precise positions of the welded channels were established by S H Structures using the XSteel program.