Six fire engines and around 40 firefighters were called to a flat fire on a Vicarage Road in Leyton.
A roof and a chimney stack leading from the first to the second floor in a flat above a shop, were destroyed by fire. A small part of the flat's loft space was also damaged in the blaze.
Six adults and three children left the premises before the Brigade arrived.
The Brigade's 999 Control officers were called at 2355 and the fire was under control by 0237. Fire crews from Leyton, Walthamstow, Stratford, Leytonstone and Homerton fire stations were in attendance.
The cause of the fire was accidental and due to ageing timbers coming into contact with the chimney stack.