Commercial office space with Romex (NM)???

[mh183]

nj did not adopt that nec requirement what state are you in

 

[rcarroll]

Infinity - it's 2" x 4" wood framing, wood trusses that are 2" x 8", and 5/8" sheetrock. I'm a little fuzzy on the descriptions of Type III, Type IV and Type V - so what type am I describing? Do you need to know any more info to determine?

Thanks

Brett

Types III, IV, & V are typically wood frame const. or combustible construction. Types I & II are non-combustible. Block, concrete & steel.

 

[iwire]

Types III, IV, & V are typically wood frame const. or combustible construction. Types I & II are non-combustible. Block, concrete & steel.

That may be to general as many non-combustible buildings are wired with NM.

 

[don_resqcapt19]

Bob,

That may be to general as many non-combustible buildings are wired with NM.

Maybe not. The code wording says NM is permitted to be used in "structures permitted to be of Types III, IV, and V construction". If the building code would pemit this type of construction, NM could be used even where the building is of Type I or II construction.
Don

 

[iwire]

Don, I am not following you.

 

[bhsrnd]

Infinity - it's 2" x 4" wood framing, wood trusses that are 2" x 8", and 5/8" sheetrock. I'm a little fuzzy on the descriptions of Type III, Type IV and Type V - so what type am I describing? Do you need to know any more info to determine?

**All this quoted from the 2005 NEC**

(Types as defined by NFPA 220-1999, Standard on Types of Building Construction, or the applicable building code, or both.)

Type I - Fire resistive
Type II - Noncombustible
Type III - Combination of combustible and noncombustible
Type IV - Heavy timber
Type V - Wood frame

Types I and II basically require all structural elements to be noncombustible, whereas Types III, IV, and V allow some or all of the structural elements to be combustible (wood). The selection of building construction types is regulated by the building code, based on the occupancy, height, and area of the building.

 

[iwire]

Don, my point was IMO rcarroll's post and now bhsrnd's post lead people to believe that any NM in non combustible construction is prohibited when it may be code compliant.

 

[rcarroll]

Don, my point was IMO rcarroll's post and now bhsrnd's post lead people to believe that any NM in non combustible construction is prohibited when it may be code compliant.

You are correct, my post was the short answer. It in no way should take away from looking at the plans. Sorry for the confusion. Ron

 

[don_resqcapt19]

Bob,
We are saying the same thing. You have to look at what type of construction that is required to be by the building code. If it is required to be of Type I or II construction NM is not permitted. If it is permitted to be of Type III, IV or V construction, but, for some reason, was built in compliance with Type I or II, then NM is permitted.
Don

 

[pjg]

this may be a bit of a drift but here goes, I just returned from a continuing ed seminar and the subject of romex (nm cable)in commercial buildings was brought up. The area inspectors are beginning to enforce that romex cannot be installed in a attic space(not drop ceiling) or in a unfinished basement of a commercial building. Their reason is in 334.10 (3) that romex must be concealed (See article 100 for that definition)by a 15 minute finish rating.

In 334.15 (c) and 334.23 allow it for the basements and in attics, the inspectors are saying that those two articles are trumped by 334.10 (3).

Any thoughts or is this being enforced anywhere else?

As the OP asked there are certain limitations to nm in other than dwellings. in this area it is still widely used.

 

[bjp_ne_elec]

PJG - interesting. I ran by my local inspector and everything is fine, at least in his jurisdiction. I really didn't ask him to explian - simply gave him a "look see" in the ceiling. He didn't have any issues. The attic was previosly loaded with NMB.

Are these guys holding this line for brand new installations? Would they allow more NMB run in the attic if there was already an existing installation?

Thanks,

BRett

 

[pjg]

PJG - interesting. I ran by my local inspector and everything is fine, at least in his jurisdiction. I really didn't ask him to explian - simply gave him a "look see" in the ceiling. He didn't have any issues. The attic was previosly loaded with NMB.

Are these guys holding this line for new? Would they allow more NMB run in the attic if there was already an existing installation?

Thanks,

BRett

I'm not sure if they would allow any futher installation but, this become a real problem with a change of use. Discussion has it that a change of use will require re-wiring of the attic and basement. in addition if the buiding was vinyl sided, ???? (I don't think it has 15 min. finish rating).

 

[bjp_ne_elec]

This could be huge. Thanks for the post. I'm going to move cautiously on bidding any commercial buildings with NMB. Will have the AHJ give me a ruling before I turn out the proposal.

 

[Davis9]

This could be huge. Thanks for the post. I'm going to move cautiously on bidding any commercial buildings with NMB. Will have the AHJ give me a ruling before I turn out the proposal.

MA allows NM in Types I + II Structures with stipulations.


Ma ammendments

CMR 527 Index

Tom

 

[M. D.]

In 334.15 (c) and 334.23 allow it for the basements and in attics, the inspectors are saying that those two articles are trumped by 334.10 (3).

Any thoughts or is this being enforced anywhere else?

334.10(3) is for "Other structures" than those already mentioned of types III IV and V. One of the the ones mentioned is (1) one and two familly dewllings.

A similar question was asked at a seminar I attended held by Joe Ross last weekend, pertaining to a detached garage of a dwelling. The question was would the N.M. need a 15 minute covering he said no as long as it is considered protected from physical damage and that it did not require a 15 minute finish rating.

 

[tcruise]

Use of nm cable in commercial building

Use of nm cable in commercial building

First and foremost, keep in mind this is outdated information ...

Years ago, I ran into a commercial rewire and found that NM (romex) was actually being specified. I conferred with the AHJ and then validated the info in the actual NEC at that time.

The two main factors were that it was only a two-story building and the COMMERCIAL USE was most critical -

If it was to be a gathering place where (I believe the specified limit was) 40 people or more would be expected, romex was not allowed ...

But in my case, it was being converted into a few offices with a staff that would be well under the 40 persons limit of a general meeting place ... romex WAS ALLOWED.

I would pay further attention to Infinity's reply:
"If the building is 10 years old than NM cable was likely permitted when the building was originally constructed. NM cable was allowed in structures not exceeding 3 stories above grade up to the 1999 NEC. In the 2002 NEC the prohibition changed to structures of certain construction types and the above hung ceilings prohibition was added as well.

So now under the 2005 NEC you would be permitted to use NM cable if it weren't above a hung ceiling and the building is of a construction type listed in 334.10."

It so happens I am beginning to research an related issue and came across your post. I feel like a dummy for not knowing the answer to my own question ... I have a 3-story building (with a penthouse added) that is a residential 4-plex. The first floor is being renovated (Hurricane Katrina) and MC cable was used throughout with one exception - the electrician used romex to some 120-vac lightin fixtures in cabinetry. The lights look like low-voltage surface mount cabinet/accents lighting, but the absence of a transformer is obvious. The surface mount fixtures are not suitable as junctions box for mc cable and retrofitting will be an expensive nightmare (wall are decorative tile ...).

Though the building may be considered more than three stories with the penthouse, am I still allowed to use romex as it is multi-family, combustible construction?