# Romex in a commercial building



## B4T (Feb 10, 2009)

You can't use NM above a suspended ceiling


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## Grimlock (Aug 4, 2009)

Better check with the AHJ before committing to anything.


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## electro916 (Jan 16, 2009)

Building classifications and fire ratings (stated by the IBC) determine which cabling methods can be used. Even though you can use romex in the walls, any cable above the ceiling in a common area cannot be romex. I usually run MC for all my lighting and feed as much as I can through the walls, But for the runs I cannot, I use MC to the first box in the walls then switch to romex from there.


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## ampman (Apr 2, 2009)

Black4Truck said:


> You can't use NM above a suspended ceiling


 why is it a plenum


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## Speedy Petey (Jan 10, 2007)

ampman said:


> why is it a plenum


No. 
Because of 334.12(A)(2)


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## ToddH (Apr 27, 2008)

I know the code you are talking about. I am from NJ and I have seen it alot above drops. In newark I did a small store and the light where up already powered with romex. There must be somthing to get around that. I will talk to the inspector anyhow.


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## B4T (Feb 10, 2009)

ampman said:


> why is it a plenum


 
*
334.12 Uses Not Permitted.
(A) Types NM, NMC, and NMS. ​*​​​​Types NM, NMC, and
NMS cables shall not be permitted as follows:
(1) In any dwelling or structure not specifically permitted
in 334.10(1), (2), and (3)​
_Exception: Type NM, NMC, and NMS cable shall be permitted
in Type I and II construction when installed within
raceways permitted to be installed in Type I and II
construction.​_(2) Exposed in dropped or suspended ceilings in other​than one- and two-family and multifamily dwellings


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## ToddH (Apr 27, 2008)

is that a chang in 08 or has it been like that?


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## ampman (Apr 2, 2009)

Speedy Petey said:


> No.
> Because of 334.12(A)(2)


 i guess i've never ran into this because i've never ran romex in a commercial building


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## B4T (Feb 10, 2009)

That is from 08


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## Magnettica (Jan 23, 2007)

How about a sub panel above a suspended ceiling and above a bathroom. 

Is that legal?


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## B4T (Feb 10, 2009)

Magnettica said:


> How about a sub panel above a suspended ceiling and above a bathroom.
> 
> Is that legal?


I would think not because you need a ladder to get to it


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## Magnettica (Jan 23, 2007)

And some rule in 240 about the height of the OCPD too.

I've also seen tons of crap wiring above suspended ceilings.


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## william1978 (Sep 21, 2008)

ampman said:


> why is it a plenum


 It doesn't matter if the ceiling is plenum or not.


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## william1978 (Sep 21, 2008)

ToddH said:


> is that a chang in 08 or has it been like that?


 It's been that way for awhile. I can't tell you when it started.


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## ToddH (Apr 27, 2008)

I know you guys think i am nuts but I have seen this in a couple new buildings and I think maybe I found why in 334.10 it says it is permitted in type III, IV, V. to make it short in ceilings that pervide a thermal barrier of material that has at least a 15 minute finish rating. What do you guys think of that could that be the reason.


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## Magnettica (Jan 23, 2007)

NEC 2005

334.12 Uses Not Permitted.

(2) Exposed in dropped or suspended ceilings in other 
than one- and two-family and multifamily dwellings


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## william1978 (Sep 21, 2008)

Magnettica said:


> NEC 2005
> 
> 334.12 Uses Not Permitted.
> 
> ...


 Was that when it was added?


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## wildleg (Apr 12, 2009)

I didn't see where the OP said what kind of ceiling it was. 

If its a hard lid, the cable is concealed, and therefore permissable.

If there is a fire lid below the cable, and the cable is concealed (whether or not there is an accoustical clg below the lid), the cable is permissable.

Otherwise, as everyone said, the cable is a violation per 334.


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## stars13bars2 (Jun 1, 2009)

I think this changed in the 2002 code, but am not positive. I guess my memory can be included in the list of things that seem to be spiraling down at a ever increasing speed.


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## Magnettica (Jan 23, 2007)

william1978 said:


> Was that when it was added?


I'm not sure when that was added but it's a rule now :thumbsup:


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## 220/221 (Sep 25, 2007)

Romex in a commercial building? That's crazy talk.

Before the internets, I didn't know it was legal anywhere.:jester:


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## Mr. Sparkle (Jan 27, 2009)

I worked on an office in an office building from the 70's or so and the whole place was done in romex, there was romex above all the dropped ceilings and we were able to do the same with everything we installed...strange indeed.


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## Darkjim (Aug 7, 2009)

The 2002 code book has the same verbiage with the black line next to it(meaning something changed since the last code). Not sure where my 1999 code book is.


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## Bob Badger (Apr 19, 2009)

Not my work.


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## Bob Badger (Apr 19, 2009)




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## Mr. Sparkle (Jan 27, 2009)

That is terrifying.

All temporary? 

Nooo....

'Splain please.


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## Bob Badger (Apr 19, 2009)

Mr. Sparkle said:


> That is terrifying.


I was not terrified but I was surprised. 



> All temporary?


Only the panel mounted to the tin foil storage cabinet was temp. :blink:



> 'Splain please.


Here in MA, RI and CT a lot of commercial buildings where done with NM, the NEC allowed it. Now with the restrictions for above suspended ceilings most jobs go MC. (MA loosed that restriction up, I can run NM above a ceiling)

The jobs I was involved with would not look like this, there are ways to install the NM in these buildings and still have it look better then the pics. It turns out to be very reliable, it just looks like dung.


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## e57 (Jun 5, 2009)

Bob - there should have been a warning, or some sort of shield to such disturbing content - I was nearly dry heaving.

I'm not fond of the NM in all situations idea. While it is just wire in a cheap silly jacket and paper - I just can't see it holding up to the demands and heat in a situation like that. (even though some would be derated to use of 7A or less.)

I might feel better if it were neatly combed and spaced.... The same install in MC however would have less effect on my stomach as it would be camouflaged in the same color...


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## macmikeman (Jan 23, 2007)

I had to do a tenant improvement flower shop in a single story strip mall one time, the whole thing had been wired with romex. There was a resturant/bar at one end of the building, and drop ceilings throughout the whole thing with a semi- ok job of firewalls but gaps at some beams between just large enough for rodents to move from one side to another. It was all done back when it was still legal to run romex above drop ceilings. 
Anyway, when we pulled the drywall off the interior walls so I could start running my mc cable and emt, the rats had chewed up massive amounts of romex sheath and wire insulation. In The Metal Studs Areas. Some was from other tenants panels - romex cables in the side walls. Not so easy to disconnect some other tenants messed up wiring - they didn't want to shut down anything that would interrupt business. Scary. Really turned me off to any thoughts about using nm in commercial buildings, I'll let others do it but mc cable for me.


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## Bob Badger (Apr 19, 2009)

e57 said:


> Bob - there should have been a warning, or some sort of shield to such disturbing content - I was nearly dry heaving.


Sorry. :laughing:

_'Caution, the following pictures may be disturbing to fans of conduit'_



> I'm not fond of the NM in all situations idea. While it is just wire in a cheap silly jacket and paper - I just can't see it holding up to the demands and heat in a situation like that. (even though some would be derated to use of 7A or less.)


When we were doing it we would be careful not to bundle like this, I also agree with you that most of that would be not be rated over 7 amps. That said I am very familiar with the circuitry in these stores and most of those NMs will have less then 10 amps, many less then 5 amps and many are control circuits with less then an amp. So heat will not be a problem, still an NEC problem and ugly.



> I might feel better if it were neatly combed and spaced....


I won't say when we do it that we 'comb it' but generally run in bundles of three parallel to building framing. 




> The same install in MC however would have less effect on my stomach as it would be camouflaged in the same color...


MC is much more common at this point.


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## oldman (Mar 30, 2007)

i don't know the reference off the top of my head, but NJ does have an exception that allows NM above a drop ceiling...might just be in rehab code...didn't know this until about 1 yr ago....

where the heck is Celtic...he'd know the reference...you just can't trust that guy to be there when needed


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## Mr. Sparkle (Jan 27, 2009)

If I recall correctly it has something to do with occupancy.


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## user4818 (Jan 15, 2009)

220/221 said:


> Romex in a commercial building? That's crazy talk.
> 
> Before the internets, I didn't know it was legal anywhere.:jester:


You need to get out more.


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## leland (Dec 28, 2007)

toddh said:


> is that a chang in 08 or has it been like that?



2002. Wording just changed in '05.
my mistake.


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## leland (Dec 28, 2007)

Bob Badger said:


> I was not terrified but I was surprised.
> 
> 
> 
> ...



where? We been shut off with that for a while now.


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## Bob Badger (Apr 19, 2009)

> (MA loosed that restriction up, I can run NM above a ceiling)





leland said:


> where? We been shut off with that for a while now.


I do not have my 2008 here but in the 2005 MA amendments 334.12(A)(2) allows NM above suspended ceilings in other than dwelling units if the cable follows the surface of the building or is connected to fixtures per 334.30(B)(2).

I am 99% positive the rule remains the same in the 2008 MA amendments.


Here is an unofficial copy of the 2008 MA Amendments


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## nitro71 (Sep 17, 2009)

You need to check ceiling type, occupancy and what type of structure the building inspector is classifying this as and local codes before you can use NM in it. If you are bidding this then you also need to check the project specs. If it's T&M I wouldn't mess with NM in metal stud construction.


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## crazyboy (Nov 8, 2008)

oldman said:


> i don't know the reference off the top of my head, but NJ does have an exception that allows NM above a drop ceiling...might just be in rehab code...didn't know this until about 1 yr ago....
> 
> where the heck is Celtic...he'd know the reference...you just can't trust that guy to be there when needed


I was going to say something has to be up with NJ then, because we've done a few and they've passed :thumbup:. Not sure why we used romex, its not up to me so it doesn't matter.


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## Mr. Sparkle (Jan 27, 2009)

Ok, I ran across it today.....

Technical Amendments
(modifications to adopted codes)

N.J.A.C. 5:23-3.14 – 3.22:

Section 334.12(A)(2) is deleted in its entirety.


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## waco (Dec 10, 2007)

Old electricians told me the restriction on using NM in commercial, dropped ceilings was because the space above a dropped ceiling is a plenum. I never questioned them, one way or another.

My problem with NM is its vulnerability to vermin damage and the fact that it burns and burns pretty well. I've worked many older homes where NM passing through top plates was chewed by mice trying to gain bigger openings. I can't say I've seen any home burn as a result, but the damaged NM is pretty sobering.

Of course, vermin control also helps, but I doubt they can be eliminated.


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## Bob Badger (Apr 19, 2009)

waco said:


> Old electricians told me the restriction on using NM in commercial, dropped ceilings was because the space above a dropped ceiling is a plenum. I never questioned them, one way or another.


That is basically true, but not all spaces above suspended ceilings are plenums or air handling spaces.


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## B4T (Feb 10, 2009)

waco said:


> Old electricians told me the restriction on using NM in commercial, dropped ceilings was because the space above a dropped ceiling is a plenum. I never questioned them, one way or another.


Sometimes there is just an "egg crate" grill in the ceiling that allows the return air to be recycled.

If there is a ducted return air, then it is not a plenum.


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## rdr (Oct 25, 2009)

I"m working on an assisted living complex behind another contractor. It has wood frame and hard ceilings in all the rooms but drop ceilings in the hallways. We had to add ranges to what was on the original plans but all the drywall is up and the first and second floors have almost literally no attic. No man could get in there for all the crap in it, and it's only a foot and a half two feet tall to begin with. It can't be done. 

The inspector allowed us to fish 8-3 nm across the rooms but said absolutely positively no romex above the drop ceiling but he will allow us to run romex to the hallways set a box and either sleeve the romex in EMT all the way to the electrical rooms or pull wire between the two and make it up to the romexes coming out of the rooms. I'm not a big fan of romex either so I wouldn't bother picking that battle.


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## adnoh (Dec 10, 2009)

By chance in the hallway a fire corridor. I would be really concerned with what adding a fixed cooking equipment does to the occupancy rating of the room and the related work to bring it up to code.


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## waco (Dec 10, 2007)

rdr said:


> I"m working on an assisted living complex behind another contractor. It has wood frame and hard ceilings in all the rooms but drop ceilings in the hallways. We had to add ranges to what was on the original plans but all the drywall is up and the first and second floors have almost literally no attic. No man could get in there for all the crap in it, and it's only a foot and a half two feet tall to begin with. It can't be done.
> 
> The inspector allowed us to fish 8-3 nm across the rooms but said absolutely positively no romex above the drop ceiling but he will allow us to run romex to the hallways set a box and either sleeve the romex in EMT all the way to the electrical rooms or pull wire between the two and make it up to the romexes coming out of the rooms. I'm not a big fan of romex either so I wouldn't bother picking that battle.


Sweet!


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## rdr (Oct 25, 2009)

adnoh said:


> By chance in the hallway a fire corridor. I would be really concerned with what adding a fixed cooking equipment does to the occupancy rating of the room and the related work to bring it up to code.


This is a brand new building going up. Not an issue I would think.


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## RIVETER (Sep 26, 2009)

*NM*



Black4Truck said:


> You can't use NM above a suspended ceiling


 Is this true?


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## Speedy Petey (Jan 10, 2007)

RIVETER said:


> Is this true?


I don't know. Is it? :whistling2:




Hint: 334.12


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## RIVETER (Sep 26, 2009)

*Romex*



Speedy Petey said:


> I don't know. Is it? :whistling2:
> 
> 
> 
> ...


Why ask a question with another question? Just give your opinion and possibly I can agree with you.


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## Speedy Petey (Jan 10, 2007)

It's not an opinion. It is right in the code book in black and white. I just thought you'd want to read it for yourself. 

It's allowed in one and two family dwellings. Nowhere else.

The text is also right in post #8.


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## B4T (Feb 10, 2009)

RIVETER said:


> Why ask a question with another question? Just give your opinion and possibly I can agree with you.


 
Why not read the beginning of the thread and the answer is right there :thumbsup:


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## user4818 (Jan 15, 2009)

Black4Truck said:


> Why not read the beginning of the thread and the answer is right there :thumbsup:


:blink:


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## B4T (Feb 10, 2009)

Peter D said:


> :blink:


SQUEAK SQUEAK SQUEAK goes the little rodent :laughing:


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## user4818 (Jan 15, 2009)

Black4Truck said:


> SQUEAK SQUEAK SQUEAK goes the little rodent :laughing:


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## RIVETER (Sep 26, 2009)

*Romex in commercial buildings*



220/221 said:


> Romex in a commercial building? That's crazy talk.
> 
> Before the internets, I didn't know it was legal anywhere.:jester:


Other than the law of the land, tell us why using romex in a commercial building is UNSAFE.


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## user4818 (Jan 15, 2009)

RIVETER said:


> Other than the law of the land, tell us why using romex in a commercial building is UNSAFE.


When you install romex in a commercial building it will burn down instantly.


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## B4T (Feb 10, 2009)

Peter D said:


> When you install romex in a commercial building it will burn down instantly.


It will also give off toxic fumes when burning the building down, but not as bad as the couch, curtains, rug, cabinets... you get the idea


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## RIVETER (Sep 26, 2009)

*kRomex*



Peter D said:


> When you install romex in a commercial building it will burn down instantly.


Well, I would say that, that is a good enough reason not to use it.


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## B4T (Feb 10, 2009)

RIVETER said:


> Well, I would say that, that is a good enough reason not to use it.


He was joking :no:


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## Speedy Petey (Jan 10, 2007)

Black4Truck said:


> He was joking :no:


:laughing:

Did you _really_ have to post this?


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## user4818 (Jan 15, 2009)

RIVETER said:


> Well, I would say that, that is a good enough reason not to use it.


Yeah! Exactly! That's what I'm talking about!


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## RIVETER (Sep 26, 2009)

*Romex*



Black4Truck said:


> He was joking :no:


I just never know. I had a job many years ago that I was told the same thing...NO romex...Just EMT. When I protested,or actually just ask why, they could not find an answer, and allowed me to use romex. It is as safe as anything.


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## B4T (Feb 10, 2009)

Speedy Petey said:


> :laughing:
> 
> Did you _really_ have to post this?


Didn't want to take a chance on him going out in public talking about this forum and the hazards lurking behind closed walls


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