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Stainless a winner for roof cladding

Posted 1 March 1998

Kuala Lumpur's new international airport terminal will open within a month and travellers will be sheltered by a A$17 million stainless steel roof which has largely been developed by Australian expertise and innovation.

KL airportThe roof profile of the contact piers and air bridges (60,000m2 total area) had to satisfy a number of criteria, including rainwater runoff, resistance to wind uplift, and a smooth, painted appearance. The roof area comprises a composite system with an outer metal membrane of fully-welded stainless steel. Further complicating the design, the architect (MJAC) wanted to avoid valley gutters on the roof's curves.

Around 280 tonnes of 0.4mm grade 316 stainless were used for the roof and unique, tapered sheet, roll forming technology was developed to accommodate curvatures in the roof. While rollforming is normally used on parallel edge products, Chadwick Technology (Forestville, NSW) and Horton Engineering (New Zealand) developed a rollformer which was capable of rolling roof sheet in excess of 20 metres long, with the edges tapering to a pre-determined dimension. All of the taper, shear and rollforming equipment was computer controlled to obtain correct dimensions.

Similarly, a fully automated welding system was designed to weld at 5 metres/minute (resulting in a total of 125km of welding), with the generated heat being water cooled. Fixing clips, which were welded within the seam roof, had to allow for thermal movement of up to 20mm. To provide the unwelded surface appearance, a rib cap was designed to conceal all the welds, fixings and unpainted sections.

Bill Mansell, Chadwick's Engineering Director, said MJAC specified stainless steel to provide the client with a lifetime investment in maintenance free roofing. The stainless steel sheet, which was coil coated with a dark green fluorocarbon PVf2, was supplied by Avesta Sheffield (Castle Hill, NSW) and special end fascia and architectural trims were fabricated by the Townsend Group (Mortdale, NSW).

The airport is opening in February/March this year and it will be fully operational for the Commonwealth Games in September 1998. The roof, which is a finalist in the Gold Circle Award for Innovative Roofing from the USA's National Roofing Contractors Association, is certain to give international visitors to Kuala Lumpur a strong, visual impression of Australia's design and fabrication capabilities.

This article featured in Australian Stainless Issue 11 - March 1998.