I am extending a ring main, with 2.5 mm cables.
Is it best to drill two small holes in a joist, or one big one?
By small I mean 11mm, big I guess about 16mm.
I know that holes have to be three diameters apart, and I'm putting them in the middle of the joists, which are about 7 inches across in my 150 yr old house.
What do you professionals do?
Is it best to drill two small holes in a joist, or one big one?
By small I mean 11mm, big I guess about 16mm.
I know that holes have to be three diameters apart, and I'm putting them in the middle of the joists, which are about 7 inches across in my 150 yr old house.
What do you professionals do?