Blowtorch ‘unlikely’ to spark fire

The roofing material and equipment used in the International Convention Centre would be extremely unlikely to be the source of the devastating fire to strike the multimillion-dollar project, says an industry body.

The Waterproofing Membrane Association gave a detailed account of how its roofing system works after the bitumen-mix roofing product found itself the focus of speculation following the fire.

It took more than 150 firefighters four days to put out the fire at SkyCity, with 27 million litres of water pumped.

Workers on the site said an apprentice broke off from a smoko break to check a blowtorch left alight where the roofing was being done. It was said the apprentice was unable to access the area of the roofing work before the alarm was raised over the fire.

Association chairman Jim Gerbes would not comment directly on the fire. But he said general information about how the system worked would provide the public with more information on which to base its views.

“It is exceptionally unlikely an installer can get a fire to start while installing the membrane,” said the association.

The blowtorches used to heat the bitumen-based membrane had a “dead-man lever”. This meant the torch’s accelerated flame died away to a “gentle pilot flame” when not held down. The flame itself was gentle enough to be blown out in wind but did not automatically extinguish.

Even then, the torch was designed to direct the nozzle upwards if unattended.