Four fire engines and around 25 firefighters were called to a fire at a house on Wimbledon Park Road in Southfields.
Part of the attic space and the roof of a mid-terraced house was damaged by fire. There were no reports of any injuries.
The Brigade was called at 1657 and the fire was under control by 1820. Fire crews from Wandsworth, Fulham, Battersea and Wimbledon fire stations were at the scene.
The Brigade's Fire Investigators believe the fire was accidental and involved a heat gun used to strip paint.