Ten fire engines and around 70 firefighters were called to a fire at a range of sheds and an adjoining house on Lyne Crescent in Walthamstow.
The sheds were destroyed by fire as well as part of the first floor and roof of the adjoined terraced house.
One woman and one child left the property before the Brigade arrived and were treated on scene for smoke inhalation by London Ambulance Service.
A 25 metre cordon was set up and residents in neighbouring properties were evacuated from their properties as gas cylinders were involved.
Station Commander David Reed, who was at the scene, said: “Fires involving gas cylinders are particularly dangerous as some cylinders can explode when exposed to heat. A cordon was in place as a precaution whilst crews worked hard to make the scene safe.
"There was lots of smoke so local residents in nearby properties were advised to stay indoors and keep their windows and doors shut.”
The Brigade was called at 0410 and was under control by 0707. Fire crews from Walthamstow, Tottenham, Chingford, Leyton, Woodford, Leytonstone, Stoke Newington and Edmonton fire stations were at the scene.
The cause of the fire is undetermined.