On your marks

A modern stadium roof is a very complex arrangement. As well as absorbing noise and channelling wind, the MCG's roof structure was designed to provide optimum protection from rain and sun.

Academy Roofing, the main roofing contractor on the project, was responsible for constructing the circular, hinged roof, which is suspended by an intricate web of cabling. Working on the structure required careful planning and material selection. Due to height and wind issues, a keen focus on safety was essential, says Karl Brown, the roofing company's director.

"Because of the height and wind, we wanted to do as little as possible at roof level. This meant we were constructing panels between 13-15m wide and 12m long at ground level and craning them into position. With limited workspace, this in itself was tricky, so we had to develop a close working relationship with Grocon."

Brown states his design brief as supplying and installing a roofing package using the best available products to meet the builder's budgets.

The MCG roof is a multi-layered affair. The first steps involved installing safety mesh and foil. The roof panels, constructed from Fielders 0.48mm Zincalume KingKlip 700 was then laid on top.

"At 700mm, KingKlip 700 is amongst the widest concealed-fix deckings available. Academy Roofing designed custom flashing that eliminate direct fixing penetration through the roof sheet," says Brown.

The underside of the structure was then attached. Originally the soffits were to be constructed from flat aluminium, but because of concerns over noise reflecting, Fielders suggested the use of a perforated material.

"The 0.7mm aluminium S Rib corrugated was perforated by Fielders, pre-painted and rollformed. The corrugations distort sound instead of reflecting it. The perforations allow noise to penetrate through to an acoustic blanket, which was installed in the 1m void between soffit and roof," says Brown.

VM Zinc panels on the facade of the Northern Stand were folded by Fielders in a joint venture with Academy Roofing.

"One of VM Zinc's features is a technical service. We sent through our site measurements, and they were drawn up into CAD plans, which greatly assisted the speed and accuracy of the project."

After a substructure was built, the 2m cassette panels were invisibly fixed.

"We used the VM Zinc FPS Cassette System, the first time it's been used in Australia, which was chosen because of its natural grey look. It's environmentally friendly, requires no maintenance and isn't sensitive to corrosion; rather, it protects itself by developing a patina that gives it an exceptional long life span," says Brown.

For more details, contact Academy Roofing, phone (03) 9560 6611, fax (03) 9560 4422. For product information contact Fielders Steel Roofing, phone 1800 182 255, website: www.fielders.com.au. For Umicore Australia - VM Zinc, phone (02) 9955 4400 or (03) 9362 6500, fax (02) 9955 1144 or (03) 9362 6555, or visit: www.vmzinc.com.

Story by: Trendsideas