Ten fire engines and around 70 firefighters tackled a fire at a mid terraced shop with dwellings above on Salisbury Road in Eastcote.
The roof and part of the second floor of two flats were destroyed by the fire. A small part of the roof of a third flat was also damaged, alongside the internal ceiling of a fourth flat. Three flats on the first floor and shops on the ground floor were damaged by water.
One of the Brigade's 32-metre turntable ladders was used at the scene as a water tower to help fight the fire from above.
Control Officers took the first of four calls at 1858 and mobilised crews from Ruislip, Harrow and Northolt fire stations to the scene. The fire was under control by 2151.
The cause of the fire is under investigation.