Fire and Emergency finds NZ International Convention Centre Fire accidental

22 April 2020

Fire and Emergency New Zealand investigators have found the cause of the New Zealand International Convention Centre fire in Auckland’s city centre on 22 October last year was accidental.

The Convention Centre was under construction at the time of the fire.  At its peak nearly 30 appliances and around 150 firefighters battled the major blaze which took ten days to fully extinguish.

Fire and Emergency Te Hiku Region Manager Ron Devlin says ‘the official investigation into the cause and origin of the fire found 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’.

‘Our investigators concluded the fire started after the cardboard inner of a cap sheet roll was momentarily exposed to a flame from a worker’s gas torch and began to smoulder,’ Ron Devlin says.

‘After smouldering unnoticed inside the roll, an intense fire developed that burnt through the top layer of the cap sheet, and then spread across the level 7 roof membrane.

‘It is worth noting we eliminated anecdotal speculation at the time that an inexperienced contractor caused the fire by leaving a blowtorch going prior to leaving the area for lunch.

This did not happen. 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.’ 

Mr Devlin says it is a significant step forward to have the cause and origin report completed.

‘The NZ International Convention Centre fire was a complex and dangerous fire and we have been focused on ensuring the investigation into its cause was comprehensive and accurately reflected what occurred on the afternoon of 22 October.  An independent peer review agreed with our findings.’

We can now confirm the cause of the fire was accidental and we hope this will assist in the organisations involved to move forward.’

Ron Devlin says fire crews spent a huge number of hours working on the fire over a 10-day period.

‘I want to take this opportunity to thank our people who worked hard on this fire.

‘We understand the convention centre fire had a severe impact on Auckland, and we appreciate the patience the city showed while we extinguished it.’

You can find the NZICC Fire Investigation Report here.

 

Cause and Origin report summary:

A Fire and Emergency New Zealand cause and origin report into the October 2019 New Zealand International Convention Centre fire has found the cause of the fire was accidental.

The fire started on 22 October last year, with Fire and Emergency on the scene for 10 days at the Wellesley Street site.

On the day the fire started the building was in its construction phase and almost entirely closed in.

Workers were applying the top layers of the waterproofing membrane (known as the cap sheet) on to the roof on levels 6 and 7. The application process required the product to be preheated to soften its underside and enable it to stick to the surface of another layer of membrane beneath it that had already been affixed to the roof.

Beneath the two layers of membrane was a layer of plywood, that was fixed to the timber framing. Under the plywood was 100mm of thermal insulation sitting on top of two layers of Durra Panel ®.

Video footage from the morning of the fire showed roofing contractors rolling out the cap sheet on the western and eastern sides of the roof of the New Zealand International Convention Centre.

This work was being undertaken until 12.36pm and then both workers left the area at 12.39pm.

The cardboard centre of the roll that had ignited, smouldered for a period of 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.

This time delay is consistent with tests and a recreation conducted by Fire and Emergency NZ.

Strong gusting winds then contributed to a rapid and significant spread of fire across the roof.

The tests found there were no substances that were likely to have led to a spontaneous ignition at the area of origin.

Incident re-creation and cause confirmation:

A re-creation of the point of ignition was undertaken on a replica of the roof and included samples of the materials present at the time the fire started.

The re-creation was consistent with the video footage of the workers in the area in the lead up to the fire becoming visible.

Conclusion:

Based on the evidence available at the time of this investigation, the classification of this incident has been recorded as accidental.

Other possible causes now eliminated:

• An inexperienced staff member leaving a blow torch going.
• Incendiary or deliberate lighting.
• Natural causes.