Six fire engines and around 40 firefighters were called to a flat fire on Anchor Close in Barking.
Most of a four-roomed flat on the second floor of the building was damaged by fire. Part of the roof and the loft space of the residential block were also damaged by the blaze.
Station Commander Gary Wilson, who was at the scene, said: "One of the Brigade's new 64-metre turntable ladders was used to get water on to the roof of the building externally. It was also used as an observation tower, providing crews with an aerial view of the incident to help identify remaining hot spots.
"One woman left the building before the Brigade arrived and was treated on scene by London Ambulance Service crews after suffering from smoke inhalation.
"Smoke in the area has now subsided."
The Brigade's 999 Control Officers took 10 calls to the blaze.
The Brigade was called at 0831 and the fire was under control by 1002. Fire crews from Barking, Plaistow, East Ham, Ilford and Wennington fire stations attended the scene.
The cause of the fire is under investigation.