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svento
Protect wire between furring strips

I have a ceiling with joists running one way, and then furring strips running perpendicular under the joists. I have wires running parallel to the furring strips which are mostly stapled halfway up the joist, but at points they pass under the joists, but above where the drywall will eventually be. How do I protect these wires? Obviously metal nailing plates are usually the choice for wires close to the surface of wood... but in this case they are on the surface. I don't think the nailing plates are intended for this purpose and would squeeze the wire too much unless I bent them (creating a gap for the wire). I'd like to figure out the right way to protect the wire in this situation! (By the way, I know the normal alternative is to just drill a hole in the joists to pass through, but I was hoping to avoid this if possible)

keith3267
Re: Protect wire between furring strips

Drill holes. Is there some reason the wires can't go over the tops of the joists? Second floor above? You could also take small scrap pieces of furring strips, 2-3" long and nail them about 3/4" apart on each joist, put the metal strip between them and run the wire through, but drilling holes would be easier.

svento
Re: Protect wire between furring strips

The top of the joists is solid plywood, so going over isn't an option.

I like your idea of the scarp furring strips and metal plates. I may do that in one area which I can't get my drill into. Although I am leaning toward drilling the rest after all! I looked at the area more and I wouldn't need to drill as many holes as I thought I would.

Thanks for your help!

Re: Protect wire between furring strips
svento wrote:

The top of the joists is solid plywood, so going over isn't an option.

I like your idea of the scarp furring strips and metal plates. I may do that in one area which I can't get my drill into. Although I am leaning toward drilling the rest after all! I looked at the area more and I wouldn't need to drill as many holes as I thought I would.

Thanks for your help!

Most Codes do not allow holes in joists, except in the middle 1/3

Going under a joist is perfectly acceptable since NM-B (Romex) is considered "conformal" wire.
So, if run exposed it must be stapled to a firm backing and not subject to physical damage.

keith3267
Re: Protect wire between furring strips

I thought that when semi retired popped in, that he would tell you that the metal plates are not required in the ceiling like they are on walls because most people don't hang pictures and mirrors on their ceilings. (mirrors maybe) He knows the codes, on this one I am not sure, he will correct me if I am wrong.

Re: Protect wire between furring strips
keith3267 wrote:

I thought that when semi retired popped in, that he would tell you that the metal plates are not required in the ceiling like they are on walls because most people don't hang pictures and mirrors on their ceilings. (mirrors maybe) He knows the codes, on this one I am not sure, he will correct me if I am wrong.

Actually the rule applies to exposed or concealed locations having bored holes in joists, rafters, or wood members within 1 1/4" of the edge of any wood member.

keith3267
Re: Protect wire between furring strips

I stand corrected then.

Mastercarpentry
Re: Protect wire between furring strips

All of the furred ceilings I've seen were done with the idea being that the drywall attached to the furring, not the joists which leaves you well clear of the wires. Maybe yours is different.

Personally I never liked this idea (even though Tom does it on TV a lot) because this places the entire weight load of a given area on a single point instead of spreading it all along the joist. If the furring splits on that spot it doubles the load at the next joists which makes them more likely to fail similarly. I much prefer sistering to straighten out ceilings if it's needed (which it rarely is) so why bother with furring in the first place? It just seems pointless to me.

Phil

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