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View Full Version : Proper way to secure an electrical box?



Phil Thien
04-11-2010, 9:46 PM
LOL.

So if you'll remember my thread from yesterday, I had been planning on cutting a 12-gauge romex to install an outlet.

Then I realized that I could simply reverse a fixture and free-up an outlet and my problem would be solved.

But when I unplugged the fixture, the entire box came with the plug.

The box was just nailed to the joist. It looks like the nails may have been pounded into the same holes a couple of times.

I checked a few of the other boxes down there that seem like they were part of the same install, and they all seem not so secure.

Can I open the boxes, move them a little (plenty of wire), and attach with screws? Or do I have to use nails?

And if I use screws, what kind should I use?

Sorry for the dumb questions. I really felt like I dodged a bullet until the box came with the plug.

I was soooo close.

Wayne Hendrix
04-11-2010, 10:08 PM
If I am inferring correctly there is no sheetrock and you have access to the joists. If this is the case just slide the box one way or the other on the joist and renail it. You dont have to move it far, 1/2" is sufficient.

If you dont have access to the joists and it is a plastic box I have run 1-1/4" screws at an angle through the corners from inside of the box to secure the box. If you go this route cover the head of the screw with some silicone or at a minimum some electrical tape to protect the wire from abrasion. You can do this with a metal box but you have to predrill the holesThis may not pass inspection in your area but my inspector approved it as long as the screw heads were covered.

Edit: I forgot to mention that if you have access to the outside of the box you can replace the screws with nails without a problem. At least I am not aware of one in NEC and I have never had problems locally doing so.

Phil Thien
04-11-2010, 10:17 PM
Wayne, these boxes are part of the surface wiring in the basement. All pretty much attached to the joists.

It would be easier for me to shoot screws in than nail, as I'm working inside the box and would rather not be that close to the wiring with a hammer.

Can I use any screw I want? I have some Kreg 1-1/4" coarse screws normally used for pocket hole joinery.

I need to secure the box that is now hanging, and one other box that I found that seems to move back and forth on the nails by 1/4". The other boxes seem to have some wiggle to them, but no front to back play.

Wayne Hendrix
04-11-2010, 10:30 PM
I just went back and re-read your other thread so, its surface mounted metal boxes? If that is the case I would just replace the nails with the screws and put some tape over the heads. The pocket hole screws will work great because the washer head will help secure the box.

Aaron Wingert
04-11-2010, 10:53 PM
No need to complicate this....Your Kreg screws will do a great job of securing the box, provided you're installing from the inside of the box and the threads aren't exposed inside the box...Sounds like that's the case. There's no need for tape on the screw heads.

Wayne Hendrix
04-11-2010, 10:56 PM
No need to complicate this....Your Kreg screws will do a great job of securing the box, provided you're installing from the inside of the box and the threads aren't exposed inside the box...Sounds like that's the case. There's no need for tape on the screw heads.

Actually I agree but the city electrical inspector did not. He wanted the tape.

Aaron Wingert
04-11-2010, 11:06 PM
Actually I agree but the city electrical inspector did not. He wanted the tape.

I believe I'd have asked for a code section on that one! :confused:

Von Bickley
04-11-2010, 11:37 PM
I believe I'd have asked for a code section on that one! :confused:

I agree with Aaron. I'm a retired electrician and I have never heard of taping up screw heads.

Aaron Wingert
04-12-2010, 12:33 AM
I agree with Aaron. I'm a retired electrician and I have never heard of taping up screw heads.

This building inspector has never required it, that's for sure. :)

Wayne Hendrix
04-12-2010, 12:34 AM
I agree with Aaron. I'm a retired electrician and I have never heard of taping up screw heads.

I think it was mostly because they were inside a plastic nail on box that there was no way to nail due to the location that the customer wanted the receptacle. I am not going to argue with the inspector when I can pull a piece of tape off my belt and pass the 4-way. Its the only time I have ever done it (the tape that is, I have put plenty of screws inside boxes).

The only reason I mentioned it here is because I am so leary of giving electrical advice over the internet that I always go way overkill with safety, but like I said I agree there is no need for it, there are plenty of things built into the box that will do more damage to the wire than the screws.

Foras Noir
04-12-2010, 1:44 PM
Scrap it. Go to an electrical supply house (not a big box) and ask for an "old work" box. It costs about $2. Saves you lots of time.

Jeff Fischer
04-13-2010, 12:05 AM
Never had to put tape over nail heads, but we commonly wrap the back of the outlet with tape (covering the screws). We usaully do this in all metal boxes to prevent accidental shorts and also in plastic boxes with screws exposed on the inside. Of course we ground all outlets and switches, too.

Play it safe! You may not get a second chance.

Jeff