The fire that broke out on the roof of SkyCity’s under construction National Convention Centre in October last year has been classed as an accident.
In a Fire and Emergency New Zealand report released this morning, investigators found it was started accidentally by workers who were fitting the roof. The report says it was “inadvertently caused when the top layers of a waterproofing membrane - or cap sheet - were being laid on the roof of the convention centre”.
Workers had applied the top layers of the waterproofing membrane, known as the cap sheet, on to the roof before leaving the area at 12.39pm. In order to apply the product, Fire and Emergency says it has to be preheated.
This started a chain of events which saw the cardboard roll at the centre of the cap sheet ignite and smoulder for up to 38 minutes before starting a larger blaze, authorities concluded.
When the fire was at its peak nearly 30 trucks and around 150 firefighters were battling it. The blaze took 10 days to fully extinguish.
At the time, there was widespread speculation that a flame from an inexperienced worker’s gas torch had started the fire, but Ron Devlin of Fire and Emergency says the investigation found it not to be the case.
“Our investigators found all gas bottles around the origin of the fires were turned off for the lunch break. There were no inexperienced contractors working in the area at the time,” says Mr Devlin.
“We can now confirm the cause of the fire was accidental and we hope this will assist in the organisations involved to move forward.”
The convention centre’s main contractor, Fletcher Construction, says it has begun a thorough review of torch-on roofing membrane processes across its sites.
Peter Reidy, chief executive, says the company’s own investigators have come to a similar conclusion about the cause. He says it should be noted that the roofing product is extremely common, as is the way it is applied.
“The subcontractors working on the roof of the NZICC had 40 years’ experience between them, were employed by one of the two largest specialist roofing membrane installers in Auckland and the firm was approved by the product manufacturer.
“While the FENZ investigation has been underway, FCC has undertaken a thorough review of torch-on roofing membrane processes across our sites and run facilitated workshops with frontline workers.”
But the company at the centre of the report issued its own statement this morning suggesting the Fire and Emergency NZ report contains "factual inaccuracies".
"As with the initial suggestions as to the cause of the fire already referred to, MPM Waterproofing has voiced its concern to FENZ about the content of the report and the accuracy of the conclusions made in it," MPM Waterproofing said in the statement.
"MPM Waterproofing takes the view that it would be appropriate for FENZ to retract the report while further consideration is given to MPM Waterproofing’s concerns and the matter is the subject of further investigation."
In response to MPM's inaccuracies claim, Fire and Emergency issued a second statement to 1 NEWS today shooting down any idea of further investigation.
"Fire and Emergency New Zealand’s investigation team worked with investigators engaged by various parties involved in the New Zealand International Convention Centre construction project to ensure there was a common information base," says Mr Devlin.
"Many of MPM’s concerns were brought to our attention during that process. We believe they’ve been appropriately considered, along with all the other relevant evidence and commentary."
Mr Devlin says the report was independently peer reviewed prior to release.
"While other parties are free to express their own views about the cause and origin of the fire, we are confident about the conclusions we have reached."