I am running CAT6a wire around my house and I was wondering what the maximum hole size I can drill to run cable across the joists in my basement to various rooms. I should measure but the joists are 2 x 8's I believe.
According to International Residential Code, the maximum diameter of a bored hole in sawn lumber is 1/3 the depth of the board.
See this answer for more details.
A 2x8 joist has a depth 7¼", so maximum hole diameter would be 2 13/32" (
7.25" / 3 = 2.41667").