More than two hours later, around 11.50am, she was on the far side of the Waiare Rd house when the smoke alarm in the lounge went off.
She went to investigate and found the deck was on fire. She managed to put it out while calling 111. The Okaihau Fire Brigade arrived eight minutes later.
Mrs Moorhouse said she had learned never to underestimate the heat of ashes. She was going to buy a metal bucket today.
Mr Champtaloup said if it wasn't for the smoke alarm Mrs Moorhouse wouldn't have noticed the fire until much later.
"And if she had been out, the house would have been lost."
He said ashes could take as long as 72 hours to cool so had to be placed in a metal bucket and left on a non-flammable surface.
Mr Champtaloup also urged Northlanders to get their chimneys cleaned before the onset of winter. Birds' nests and soot build-up could cause chimney fires when the fireplace was brought back into use after summer.