A house fire in Christchurch has been traced to fireworks being thrown onto a roof.

The blaze broke out around 10:30pm on November 11th at Becmead Drive in Harewood.

Fire investigator Bruce Irvine said the family had just gone to bed when the smoke alarm went off and the father went to investigate.

"He didn't realise that this was actually a significant fire inside the ceiling void, so he was only seeing a small byproduct of what this fire was within this house."

Irvine said the fire spread incredibly quickly, starting in the guttering before spreading inside the wall space, and the family were very lucky to survive.

He said the latest incident was outside the designated Guy Fawkes time and again raises the question over having home-lit fireworks in New Zealand.

He told the Christchurch Star: "We want to start the conversation right here, right now. There have been far too many incidents. And we know it is going to happen, that is the frustrating thing about it. These fires are avoidable."

Irvine told the paper that if someone had died, he would expect a murder charge to be laid.