Hello,
Why is it that metal back boxes come in 25mm, 35mm, and 47mm sizes but surface mount pattress boxes only come in 25mm and 47mm sizes?
I would like to wire a spur and I wasn't sure that a 25mm box would give me enough room for the cables; a 35mm box would have been better. Will a 25mm box be a tight fit?
I see Toolstation sell 32mm boxes but they are the same size as Wickes' 25mm boxes so perhaps one measures internal depth and the other external depth?
Thanks, Stephen.