NM stapled beside furring strips

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al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
So you can zig zag up the furring bay by stapling to the furring strip on one side, then the other, and it's all good, as it's only "almost parallel"?

Yeah, we've played these word games before. . .or maybe its a math definition game, . . . or maybe it is what I'm typing right now: It's an abstracted game about a game.

Whatever.

Side stepping your parry, I lift up Rob's near perfect zen koan of "installing parallel to":
You're correct it probably will but it's still not a code violation.
Staple it to the stud without the 1.25" clearance and it is a violation.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
It's also not going to move if a screw starts pushing it. The screw will just go right through it.

I've stated my position on this before. It should be prohibited to run wiring within a 1x furred wall cavity. No matter how you do it it's never going to be 1-1/4" from the back of the sheetrock. The Code doesn't think that's important but a screw or nail in the right place is going to get the cable.

-Hal
 

kwired

Electron manager
Location
NE Nebraska
I've stated my position on this before. It should be prohibited to run wiring within a 1x furred wall cavity. No matter how you do it it's never going to be 1-1/4" from the back of the sheetrock. The Code doesn't think that's important but a screw or nail in the right place is going to get the cable.

-Hal

With that approach one must assume nothing will ever penetrate the wall more than 1-1/4 inches beyond the framing either - not true. The risk is simply higher near the framing members. I've seen longer than needed nails or screws used many times to fasten all sorts of items to a wall, that 1-1/4 rule just helps prevent mishaps from some of the most common things out there.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
With that approach one must assume nothing will ever penetrate the wall more than 1-1/4 inches beyond the framing either - not true. The risk is simply higher near the framing members. I've seen longer than needed nails or screws used many times to fasten all sorts of items to a wall, that 1-1/4 rule just helps prevent mishaps from some of the most common things out there.

True. But after a wall is finished, nobody knows where the studs are, or they aren't even looking for them, least of all homeowners. At least with 2x framing the nail or screw can push the cable back, especially with Colorado Jims that allow movement and the cable is probably more than 1-1/4" from the back of the sheetrock also. But with only 3/4" behind the sheetrock, it's guaranteed that even a 1" screw or nail is going to pin the cable back against the concrete and penetrate it. The odds become exponentially greater for damage.

-Hal
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
True. But after a wall is finished, nobody knows where the studs are, or they aren't even looking for them, least of all homeowners. At least with 2x framing the nail or screw can push the cable back, especially with Colorado Jims that allow movement and the cable is probably more than 1-1/4" from the back of the sheetrock also. But with only 3/4" behind the sheetrock, it's guaranteed that even a 1" screw or nail is going to pin the cable back against the concrete and penetrate it. The odds become exponentially greater for damage.

-Hal

Sounds like you should make a proposal for the 2023 NEC.
 

jap

Senior Member
Occupation
Electrician
The protection plate is required to be a minimum of 1/16". The exception allows for the plate to be less than 1/16" if it is listed and marked.


300.4(A) Cables and Raceways Through Wood Members.
(1) Bored Holes. In both exposed and concealed locations,
where a cable- or raceway-type wiring method is installed
through bored holes in joists, rafters, or wood members,
holes shall be bored so that the edge of the hole is not less
than 32 mm (1 1 ⁄ 4 in.) from the nearest edge of the wood
member. Where this distance cannot be maintained, the
cable or raceway shall be protected from penetration by
screws or nails by a steel plate(s) or bushing(s), at least
1.6 mm ( 1 ⁄ 16 in.) thick,
and of appropriate length and width
installed to cover the area of the wiring.
Exception No. 1: Steel plates shall not be required to
protect rigid metal conduit, intermediate metal conduit,
rigid nonmetallic conduit, or electrical metallic tubing.
Exception No. 2: A listed and marked steel plate less than
1.6 mm ( 1 ⁄ 16 in.) thick
that provides equal or better protec-
tion against nail or screw penetration shall be permitted.
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Unless there's a code section that explains it more clearly, I, like Coppersmith, would like to know where in above statement it indicates that the cable must be kept 1 1/4" away from the face of the stud.

If nailing the cable to the side of a furring , you're not going through a wood member or through a bored hole.

The whole thing about the cable entering an outlet box connector at "not exactly parallel to the framing member for 8 or 12 inches" just seems silly to me.

JAP>
 

kwired

Electron manager
Location
NE Nebraska
Unless there's a code section that explains it more clearly, I, like Coppersmith, would like to know where in above statement it indicates that the cable must be kept 1 1/4" away from the face of the stud.

If nailing the cable to the side of a furring , you're not going through a wood member or through a bored hole.

The whole thing about the cable entering an outlet box connector at "not exactly parallel to the framing member for 8 or 12 inches" just seems silly to me.

JAP>

I agree, yet many still think that if it is secured to the side of the stud it must be 1-1/4 from the face of the stud, when in fact the wording only mentions bored holes. Good design practice is still to keep away from areas more likely to have something penetrate though - but that is good practice not code requirement.
 

jap

Senior Member
Occupation
Electrician
I agree, yet many still think that if it is secured to the side of the stud it must be 1-1/4 from the face of the stud, when in fact the wording only mentions bored holes. Good design practice is still to keep away from areas more likely to have something penetrate though - but that is good practice not code requirement.

So why are so many defending a rule where that's not actually what it says?

JAP>
 

jap

Senior Member
Occupation
Electrician
By the wording, to me, the OP is correct and understood the rule more so than the inspector.

Unless there's some wording otherwise that I'm not aware of.

JAP>
 

jap

Senior Member
Occupation
Electrician
Apparently he is aware of the 1-1/4" rule. So I'm confused about what he is talking about. Are these the usual 1x furring? Did you just assume that because you only had 3/4" that you could just staple your NM down it and the 1-1/4" rule didn't apply?

The 1-1/4" rule allows you to go horizontally away from the edge of the framing member also in order to comply. So in this case that's the only way to do it. You should have stackers and/or Colorado Jims on your truck- use em'.

-Hal

That's exactly what I would assume.

What part of the rule states that you can't ?

If you have a 1x furring strips which are generally 3/4" thick 2 or 3" wide attached to a block wall, and you're running NM along side that furring strip, how does moving the cable horizontally any distance away from the side of the furring strip make it any more safe?

It doesn't.

You don't gain any more than 3/4" of an inch clearance no matter where you move the cable in the void.

JAP>
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
By the wording, to me, the OP is correct and understood the rule more so than the inspector.

Unless there's some wording otherwise that I'm not aware of.

JAP>

The OP is not asking about bored holes in furring. Rob introduced 300.4(A)(1) to talk about nail plates. For the OP scenario, his inspector saw a 300.4(D) situation. 300.4(A)(1) does not apply.

So the "wording" is in 300.4(D).
 

jap

Senior Member
Occupation
Electrician
The OP is not asking about bored holes in furring. Rob introduced 300.4(A)(1) to talk about nail plates. For the OP scenario, his inspector saw a 300.4(D) situation. 300.4(A)(1) does not apply.

So the "wording" is in 300.4(D).

That's wording I was looking for.

I agree with the inspector now. :)

JAP>
 

PaulMmn

Senior Member
Location
Union, KY, USA
Occupation
EIT - Engineer in Training, Lafayette College
I hesitate to say it, in fear of another chapter in the code--

Does the problem go away if the wiring is in metal conduit? (EMT or BX)

It's either that or surface-mounted panduit or wiremold...
 

jap

Senior Member
Occupation
Electrician
I hesitate to say it, in fear of another chapter in the code--

Does the problem go away if the wiring is in metal conduit? (EMT or BX)

It's either that or surface-mounted panduit or wiremold...

I'd bet it does, . :)

JAP>
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
I hesitate to say it, in fear of another chapter in the code--

Does the problem go away if the wiring is in metal conduit? (EMT or BX)

It's either that or surface-mounted panduit or wiremold...

Armored Cable, AC, has to be protected like NM, (2017 NEC 320.17).

EMT is safe, with exception of "severe" physical damage, therefore Article 358 does not invoke 300.4.

Edit to add: MC has to be installed per 300.4 (2017 NEC 330.17).
 
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