holes/cables in studs, 1-1/4 or 1-1/2 inches??

Old 06-24-10, 08:32 AM
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holes/cables in studs, 1-1/4 or 1-1/2 inches??

“The holes and the cable running through them must be at least 1-1/4 in. from both faces of the stud to prevent nails and screws from hitting the cable”

I think I found the above quote on this message board somewhere, but my question is – is the requirement 1-1/4 inches or 1-1/2 inches? I’m in Bergen county NJ. I read something about 1-1/2 inches this morning, after I’d drilled all of my holes at least 1-/1/4 inches back from the faces of the studs. New I’m worried the inspector may make me add nail plates.

Thanks, Mike
Old 06-24-10, 08:40 AM
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Well, Mike...no Pro.. but if you think about it...if it were 1 1/2", you could only have a 1/2" hole in a standard 2x4 stud. With 1 1/4" you could have up to a 1" hole...

I think 1 1/4" is the right number.

Yep...found this....


Holes: Do not bore holes closer than 2" from joist edges, nor make them larger than 1/3 the depth of the joist.
Notches: Do not make notches inthe middle third of the span where the bending forces are greatest.
Notches should be no deeper than 1/6 the depth of the joist. Notches at the end of the joist should be no deeper than 1/4 the depth. Limit the length of notches to 1/3 of the joist’s depth.


1” is the max diameter , we can have in 2 x 4 [3.5”] studs and avoid the 1/16” nailer plates due to the 1.25” NEC rule. (NEC rule: all wires must maintain a minimum of 1.25" from edge of stud on both sides) If you end up getting closer than this then install a metal nail plate across the studs edge. Three NM-B 12-2G ,Romex® will not require a hole larger than 1"..as 3/4" is a bit traumatic on the sheath, when pulling (3)size 12-2G NM cable.

¾” hole for (3) 14-2G

1” hole for (3) 12-2G

For structural (not electrical) reasons, keep your bored holes dead center top to bottom, and at least three inches apart (edge to edge). Don't drill through any trusses whats so ever.

Never drill any holes in TRUSS members..
Old 06-24-10, 09:07 AM
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The requirement is 1-1/4" from the nailing face of the framing member. If you have any that are shallower all you need to do is install a steel nailing plate on the stud(s) where the cable is shallow. I usually drill 7/8" auger holes through the center of the 2x4 stud.
Old 06-24-10, 03:52 PM
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I agree, im in jersey as well and i always just use 7/8" auger bits. Its easier to just buy and use one size of bit for all my holes. I never bundle more than 3 wires, and (3) 12/2's fit nicely in a 7/8" hole. in the rare instance i run bigger wire than 6/3, i just use spade bits or forstner bits. Sometimes i drop to a 1/2 or 3/4" bit for low voltage wiring, unless im running quite a few then i stick with the 7/8"

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