Several days of smouldering most likely caused a 17th Ave house to catch fire last night.
Tauranga and Greerton fire brigades were called to the property about 8.45pm after the occupant came home to a house full of smoke.
Greerton brigade station officer Steve Wright said it appeared the fire had started behind the walls of where a 1970s inbuilt fire place was.
There could have been a slow build up of heat over a few days with continual use of the fire which caused the ignition, he said.
The occupants, a couple renting, of the home had left for a couple of hours when a woman came back to a house full of smoke.
"If she hadn't come home when she did, their could have been a fully involved house," he said.
Mr Wright said there was a fire alarm in the home which was sounding even though it had been half melted off the wall.
There was structural damage in between the lounge and the dining room which he thought would needed to be replaced. There was also smoke damage throughout the house. The renters lost a few personal items in the lounge, he said.
Mr Wright said the renters had the chimney flue cleaned a few months prior which was the right thing to do each season.
Firefighters were also called to a house fire in Welcome Bay at 6.30pm.
Mr Wright said the fire was caused by the inappropriate disposal of hot ashes, the third of its kind in recent days.
The Corrina St home's occupants had dumped ashes, they believed to be cool, on a pile of lawnmower clippings that were sitting up against the side of the house.
Shortly after a fire had ignited, burning the side of the home.
Mr Wright said there was no serious damage but it was a timely reminder that hot ashes can take five days to actually cool.
The best way to dispose of them is to leave them in a metal bucket for five days before removing