PREMISES for an anchor tenant at a new Mirvac industrial estate in Sydney’s southwest are likely to set a benchmark for the seven hectare development. Nexus Industry Park at Prestons is the latest addition to Mirvac properties that will be leased to tenants.

Mobile roll forming technology was part of the building solution for the Nexus development’s first premises, a warehouse for merchant Atlas Steel. The onsite roll forming of 11,000m2 of concealed fix cladding has helped create the roof. “We looked at the idea of onsite roll-forming because we’re not just building this complex to put it on the market,” says Mirvac project manager David Brenac. “As long term owners we want to create quality buildings which will attract long term tenants and which will require minimum maintenance.”

A profile such as Lysaght Klip-Lok 700 uses a concealed fixing method and has no penetrations. “To maximise its potential benefits we went for a roof design without steps or joints from eave to peak, so deterioration and maintenance will be reduced or eliminated. For this building, the distance from eave to peak is 36.5m and that brought onsite roll forming into our calculations,” explains Brenac.

Mirvac carried out cost studies on available alternatives, spoke to roofing contractor Direct Metal Roofing and appointed BlueScope Lysaght to roll the sheets from Zincalume steel at the building site. Direct Metal Roofing director, Greg Oliver, who took on the roofing project management role at the Nexus Industry Park site, was initially sceptical of the benefits of onsite roll forming, but his experience with this operation has changed his opinion. “My only previous experience, with another supplier, had not been a good introduction to mobile roll forming,” he recalls. “The way in which the sheets were stacked after they left the roll former created a lot more work for us. Fortunately our experience on this job has been entirely the opposite.”

Oliver says the use of onsite roll forming had contributed to the smooth progress of the job and had allowed his crew to stay ahead of the building program despite wet and windy weather. “On this site without formed roads I don’t know how else you could have delivered the long sheets which were needed,” he says. “With roll forming carried out onsite there was a minimal number or truck and crane movements required. We were able to get into a rhythm that let us complete 1,000 to 1,200m2 of coverage each day. Once it’s seated on the concealed clips you just move on.”

Oliver reckons the experience gained on the project had dismissed any concerns about working with extra long lengths of roof cladding. “It’s just a matter of having the right number of workers handling each sheet whatever the length. If it’s too windy on the roof to work with longer lengths, then it’s too windy to work with shorter lengths.”

The BlueScope Lysaght mobile roll forming unit is built on a structural cage to eliminate roller distortion and the need for time-intensive adjustments. Product quality and tolerances are therefore superior to the results from a basic roll former without a structural cage.

Source: Construction Contractor