Holes through floor joists for 10/2?


So far I have run 3 new circuits from the breaker box on one side of the house to the workshop and garage on the other. I have to run a 4th.
What hole size is recommended for 10/2 in floor joists? I alway drill the smallest possible hole to minimize weakening the joists and then pulling the cable is an ordeal. Is it necessary to keep the holes any distance from existing holes, or am I making too much out of this?
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Toller wrote:

Best to drill joists in center of the joist depth, never in the center 1/3 of the span and 6" or mare from the bearing ends
Max hole size is 1/3 the joist depth & min edge distance is 2"

Section R502.8.1 Sawn Lumber:
"The diameter of holes bored or cut into members shall not exceed one-third the depth of the member. Holes shall not be closer than 2 inches to the top or bottom of the member, or to any other hole located in the member. Where the member is also notched, the hole shall not be closer than 2 inches to the notch."
Now as to multiple holes...hmmm... a single large hole would easilt accomdate all but not after they're already there. :(
If you're gutsy, careful & lucky you could enlarge an existing hole with the wire still in place OR remove the wire & hole sawa bigger hole OR just drill another hole....I'd want at least 2 or 3 hole diameters of "meat" between the holes...if my thinking is correct 1" holes could be drilled 3 or 4" apart (min) seems resonable
IMO the single large hole is looking better & better
this code passage says 2" minimum "meat" between holes...my concept depends on hole diameter...I like mine better...... code passage allows 3" holes in a 2x10 with only 2" of meat between them ...that makes me nervous
cheers Bob
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Thanks, my holes are only like 3/4" so I seem to have a pretty big safety margin. Yeah bigger holes would have saved a great deal of work, but so would a subpanel in the shop. But those boats have sailed. Though maybe not; perhaps I should bit the bullet and replace one of the 12/2 cables with a 8/3 to a subpanel. It is too late at night to be thinking about such things.
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Toller wrote:

You do not want to pull more than one cable through a hole; theoretically the currents in any given cable sum to zero but if you are pulling a LOT of current and there's a cable smack up against another one, you could get some induced voltages.
nate
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Wouldn't that imply that everyone is getting lots of induced voltages at the load panel where all the circuits meet and some are "smack up against another" as they run into the box? I have a some romex connectors with 2 and 3 circuits passing through them into the box.
Would the very short distance of "smack up against another" in these cases make the induced voltages negligible?
Thanks!
Nate Nagel wrote:

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True, in theory. And in practice in some places, homes not being one of them for typical home wiring, which is, I believe, what the OP is talking about.
The amount of induced voltage in home installations is irrelevant and can be ignored, as evidenced by MANY power cables sharing MANY holes with impunity in every home I've ever lived in.
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power tool in your head, no matter what you do." -- El Gato
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Don Fearn wrote:

That's for sure. If just having one AC cable next to another was a problem, there would be a lot of screwed up houses, including new constructions. Any induced voltage is going to be so small that it's nothing compared to the fluctuations caused by normal powerline transients, turning on/off large loads, etc.
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A 3/4" hole should be able to fit 3 12-2 cables.
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I usually drill 5/8" holes for 14/2 and 12/2 wiring. I think 10/2 wiring fits too, but it has been a while since I wired our house. You could easily switch to 3/4" if needed. Basically, the hole should be big enough for the wire to pass through easily without binding or damaging the cable sheath. Anything bigger just weakens the joists/studs.
Still, if you have lots of wiring to run, it's easier to drill a bunch of equal sized holes, even if you're running different cable sizes. This also lets you buy a good quality self-feeding auger bit, instead of a bunch of cheap bits in multiple sizes.
I only run one cable through each hole and try to space multiple holes at least 4" apart (center to center). Try to drill your holes in the center of the joist (vertically) when possible, and never near the upper or lower two inches. Space multiple holes along the length of the joist, not on top of each other vertically.
Anthony
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Toller posted for all of us...

Toller is Google still broke for you? Do you post to get permission to take a shit and how many times to wipe. ALL asked before
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If I took a shit, you would be gone!
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Toller posted for all of us...

Because you would flush yourself away you fundy idiot.
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