Romex? Say It Ain't So...

JamesNLA

Was having a discussion with a forman today. With respect to a complete rewire in a gutted 40'X100' office building. While I don't particularly do too much commercial work, I know that it should be done...or at least I do that sort of work with FMC or NMT for all the conductors. However I was challenged with the question of why not romex?

During lunch I looked it up...again.... Type 3-4-or 5 building. 15 minutes and while Romex can be visible, cannot be in a place where it can get damaged. I had actually already known that, but I was looking for some magical code refference with respect to commercial applications. And I couldn't find any. So are there any situations that Romex IS allowed in commercial office space, given the aformentioned?

Thanks

jbwhite

James, you answered your own question. Romex is allowed in any building that is type III, IV, or V. It does not matter if the structure is residential or commercial. Industrial is probably out of the question as it would most certainly be type I.

A good rule of thumb is that: If the walls and roof are made of wood, romex is allowed except in the drop ceilings. Be sure to check with the bldg dept regarding exactly what type construction the building actually is.

mdshunk

Romex is also not permitted in a non-dwelling occupancy anymore, where it is exposed.

jbwhite

I think you are taking it to an extreem when saying that the attic and crawl space wiring is exposed.

Do we have any inspectors here?

mdshunk

It's not behind a 15 minute finish if you can see it. No two ways about it.

We're talking non-dwelling, here.

jbwhite

It would be behind a 15 min finish from where the occupants are to where the wire is.

frenchsparky

"334.12 Uses Not Permitted.
(A) Types NM, NMC, and NMS. Types NM, NMC, and
NMS cables "


Marc ,,

Will you please clearify this a little what the you called NMC and NMS what the heck is that ??


but if iam reading right teh NMC is the same as UF ???
I just want to make sure i am reading this right

Merci , Marc

mdshunk

I can't. I've never seen the stuff, as far as I know. I'm not even sure it exists. I only use NM type B.

mdshunk

But that's not what it says. That's what you want it to say.

JamesNLA

Ok, in the walls which are drywalled is OK, but not in the attic?
Maybe I mis read that:
This particular building has an attic, however it will have a drywalled ceiling when complete. So, would that mean I can use Romex from lets say a recept or a switch box, run it up the stud, to a Jbox just before the plate, than switch to flex going through the plate than off into the attic? That can't be right.

So let me ask another question, why is flex so dominant in other commercial building just like this one. type V with sheet rock....and the other requirements met?


EDIT:

Wait a minute here, the first line of the quote I just did...Meaning if it was a commercial non dwelling that had no ceiling (drop ceiling is a no no, and I know that) comprised of sheetrock or any other material (lath) that gives the 15 minutes THAN romex cannot be in the attic? That makes sense for the required 15 finish. Is that correct?

mdshunk

What I'm saying is that this 334 requirement is very clear, but oft overlooked. You need something along the lines of MC or EMT anytime you can physically put your eyeballs on the wiring in non-dwelling construction. Feel free to use NM cable when the wiring is concealed in the appropriate construction types. Don't get upset with me, but the code text is very clear. The inspectors might overlook it a bit, but that's their problem.

JamesNLA

NO NO, I'm not at all upset with you, I appreciate the input, very much so.

This is actually important to me, because if I can go all romex, it will save alot of time/money for the client. I'm gonna go reread 334, thanks MD!

jbwhite

NO, that is what you want it to say.

To me exposed means that when the building is finished and in normal use, the occupants will not see it. If one must lift a tile, open a crawl door, or remove some other type access panel to get there, it is not exposed.

Otherwise all wireing is exposed always. I can always remove drywall or open box covers to get to it.

mdshunk

Yes, but "exposed" was my term. The code says the cables must be "concealed within" that 15 minute barrier. That means INSIDE. You can't be within a thermal barrier if it's only on one side.

I remain solid and steadfast, that if you can see the romex in a non-dwelling occupancy, it's a violation under 334.

jbwhite

If it is in the attic, then it is concealed within the ceiling. If it is in the crawl space it is concealed within the floor.

If I come to have a beer, I will not be able to see either.

jbwhite

md, Ryan agrees with you, and he is the best code gooo rrooo I know of..
So you must be right.

mdshunk

I wish more inspectors agreed with him. I see so much exposed romex slipping through on commercial work that I didn't win, it sorta ticks me off. I bid EMT and MC on these jobs, and the hacks get it with exposed NM and get it passed.

JamesNLA

OK, so to summerize this one last portion up, Because it's an "attic" meaning it has a means to enter into (access cover) that makes it exposed, and NOT concealed within.

An example of the latter would be a finished ceiling (drywalled) and then some kind of ply wood or non removeable sheeting that would conceal the wiring (no eyeballs can see it). And now that I think about that more, it makes sense. Thanks for the input, beers are on me!!

Dustball

A friend of mine bought a small commercial building last year and gutted it and built it to suit his needs. He had the whole building roughed in with romex and the electrical inspector ordered him to take it all down even though it was all going to be above drop ceilings. It was all re-done with MC cable.

jbwhite

Romex cannot be run above drop ceilings except in residential work.