A shepherd-collie mix named Kayla is being lauded by Ottawa's fire department after her barking woke up a Constance Bay family whose home caught fire overnight.

At around 2:45 a.m., Ottawa Fire Services got a 911 call reporting that a roof had caught fire at 1263 Bayview Road.

Kayla the dog is being lauded by the Ottawa fire department after her barking saved a Constance Bay family whose home caught fire early Friday morning. (Victoria Muise on Twitter)

Firefighters arrived to find the house completely in flames and the roof collapsed — however, the family of three had already safely evacuated by the time they got there, fire officials said.

Kayla "made excessive noise that pulled the occupants from their deep sleep and made them aware of the fire," the fire department said in a media release Friday.

Two adults and a 13-year-old girl have been displaced and are being helped by both the Salvation Army and the Red Cross, fire officials said.

The cause is believed to be "poorly-discarded smoking material" which ignited the home's front landing and quickly spread, officials said.

Damage to the home is estimated at $450,000.