Four fire engines and around 25 firefighters were called to a fire on Gloucester Road in Walthamstow.
Firefighters tackled a fire where a range of sheds and some fencing were completely destroyed. One teenage boy suffering from smoke inhalation was treated at the scene by London Ambulance Service crews.
The Brigade was called at 1508 and the fire was under control by 1618. Fire crews from Tottenham, Stoke Newington, Chingford and Edmonton attended the scene.
The cause of the fire will be investigated.