Four fire engines and around 25 firefighters were called to a garage fire on Sandycroft in Abbey Wood.
The majority of the single storey garage was damaged by the blaze. A car was also badly damaged by fire.
There were a number of gas cylinders inside the garage. They were cooled to an ambient temperature as some cylinders can explode when exposed to heat.
The Brigade was called at 0727 and the fire was under control by 0950. Fire crews from Plumstead, Erith and Bexley fire stations were at the scene. The cause of the fire is under investigation.