I am wiring a new house that is using I-joists'. have wired other houses with these. and usually will drill a 2 1/2" or 3" hole towards the top about 3" down and run most of my wires through that hole.. My question is, how many wires are allowed through that hole? and do you get into a derating problem? my inspector says it is ok. I have about 20 wires through it, and most are #12... what do you guys think?
