Six fire engines and 35 firefighters and officers were called to a fire in Western Avenue in Northolt.
Approximately 30 tonnes of waste wood was destroyed by fire.
The Brigade was called at 1703 and the fire was under control at 2120. Fire crews from Northolt, Southall, Ruislip, Hillingdon and Stanmore fire stations attended the scene.
The cause of the fire is under investigation.