Firefighters tackle the blaze the day it breaks out on October 22. Photo / supplied
Firefighters tackle the blaze the day it breaks out on October 22. Photo / supplied
KEY POINTS:
SKYCITY BLAZE - how it unfolded, October 22, 2019
12.36pm: two workers on level 7, NZICC roof
Applying torch-on waterproof membrane
12.39pm: both workers leave roof
1.03pm First signs of smoke, flame from gutter
Site tower crane operator sees smoke, sounds siren
Sudima Hotel crane operator videos blaze breakout
1.09pm: Fletcher Construction site manager makes first 111 call
1.14pm, first fire appliance arrives, second four minutes later
Fire extinguished after 10 days of burning.
Two roofing contractors were alone on the NZ International Convention Centre roof shortly before last year's disastrous fire caused by the accidental ignition of cardboard inside a roll of waterproof membrane.
The Fire and Emergency New Zealand report said the workers were interviewed last month at Duncan Cotterill Law in Auckland. They had been using gas torches to apply the material before leaving the roof at 12.39pm last October.
"Both witnesses confirmed they were the only workers on the level seven roof on October 22," the report said. They saw no other ignition sources on the roof except the two gas torches they had been using to lay the membrane, which contained bitumen.
"The probable cause of this fire is believed to be an inadvertent ignition of the cardboard centre of a roll of cap sheet torch-on waterproofing membrane. The cardboard centre of a roll smouldered for up to 38 minutes before reaching flaming combustion and providing sufficient heat to ignite the roll of cap sheet membrane to a point of self-sustaining fire," the report said.
Strong gusting winds then contributed to the rapid and significant fire spread across the roof.
But the subcontracting company which supplied the waterproof roofing membrane called for FENZ to withdraw its report.
MPM Waterproofing, a subcontractor to Fletcher Construction, strongly rejected findings. The Onehunga-based business supplied the materials which were being applied on October 22 when the fire broke out. It also worked with a subcontractor to supply the staff to install the membrane.
MPM Waterproofing had reviewed the report "and believe it contains a considerable number of 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," it said.
Ron Devlin, FENZ region chief, said that MPM's concerns were raised during the investigation.
"We believe they've been appropriately considered, along with all the other relevant evidence and commentary," he said, adding that the findings were independently reviewed before release. Other parties were free to express their views about the cause and origin of the fire, but Devlin said FENZ was confident about its conclusions.
Fletcher Construction chief executive Peter Reidy and SkyCity Entertainment Group chief executive Graeme Stephens thanked FENZ for the report.
"Our own investigators have come to a similar conclusion to FENZ, that the source of the fire was the inadvertent ignition of the cardboard centre of a roll of waterproofing membrane. We are pleased that the origin and cause of the fire has been determined and that FENZ confirms that the fire was accidental," Reidy said.
