fixing metal back box in stud wall

[Dave Plowman (News)]

Think it was common on stone solid walls to provide a degree of insulation in the cold north. With bricks, it's easier to make a cavity wall.

[Stephen]

I have not seen any with pre-drilled holes. Do they have to be placed anywhere in particular? Not on the knock out obviously! I'm guessing two per side (on the long side of a double box)

[Dave Plowman (News)]

I put the battens down the narrow sides of the box. Uses less timber.