'It's freakish': Spontaneous combustion fires on the rise

Potentially devastating and lethal cases of spontaneous combustion are an increasingly common cause of fires.

The freakish fires can erupt when something as ordinary as the household washing and drying goes awry.

In Matakana, the Sawmill Brewery co-owner Mike Sutherland has experienced the horror first-hand.

Matakana's Sawmill Brewery and Smoko Room, since rebuilt and reopened, was badly damaged by fire last year. Spontaneous ignition caused the blaze. Photo / Supplied

His brewery and its attached restaurant known as the Smoko Room has reopened, but it took months of rebuilding after the inferno on October 7, 2019.

Fire and Emergency NZ (Fenz) data released under the Official Information Act showed spontaneous combustion caused at least 114 fires last year, up from 91 the year before.

Sutherland said three different investigations were carried out after the blaze erupted 70km north of downtown Auckland.

Bags with washed and dried tea towels were dropped off at the Matakana property at 1.55pm. Photo / Supplied

It was found that the fire erupted from a laundry bag filled with tea towels which had at some point soaked up organic oil.

"It's quite freakish," Sutherland said. "You do the same thing every day for four years. Everything's fine and then..."

Video footage showed laundry being returned to the Sawmill.

A few hours later, the pile started smouldering before flames quickly ripped through the building.

The laundry is smouldering by 8.11pm, with smoke beginning to obscure the camera's view of the Sawmill Brewery. Photo / Supplied

"It's quite fascinating it can happen for starters. The results are fairly catastrophic," Sutherland said.

He said a fire investigator grabbed a scrap of cloth in the wreckage after the fire and told him to sniff it. It was a familiar, unmistakable smell.

"Basically the cause is the residual cooking oil."

Lucy Cotterill, of Fenz, said spontaneous ignition was a chemical or biological process generating enough heat to ignite reacting materials without introduced heat sources.

"Common instances of spontaneous ignition include fires in hay piles, compost piles and fabric that has been used to apply or soak up organic oil," the Fenz chief adviser said.

Flames are leaping about by 8.39pm after the spontaneous combustion. Photo / Supplied

Other hospitality businesses have also learned about spontaneous combustion the hard way.

Wellington's Backbencher Pub was ruined in a 2012 blaze, and its famous political puppets and caricatures destroyed.

Tea towels spontaneously igniting were also reportedly the suspects in a 2018 Wanaka restaurant blaze.

Sutherland said changes had been made to the way the Sawmill's tea towels were cleaned.

He said a high temperature wash was needed to get cooking oil out.

But now a cold cycle at the end of the wash was recommended.

And he also advised people using tumble dryers to switch to a cooler dry programme at the end.

Sutherland said he was thankful for the support brewers nationwide gave him after the fire.

He said brewers offered to let him make his beer on their property.

From Oamaru to Auckland, 14 different breweries helped Sutherland and co-owner Kirsty McKay get the business running again.

And after surviving the extra challenge of the Auckland August coronavirus lockdown, Sutherland said he was looking forward to a busy and successful summer.