We were in the office this morning and read and reread Art. 334, describing the allowable use and non allowable use of rx, and I have to tell ya we left with three different opinions of when you can use it and where. (gee, we've only been doing this work for years!) The main confusion is whether or not it can be used in commecial applications.I've read some previous posts but would like to rehash it. Okay lets hear from everyone else, and quote reference please. Thanks in advance!
Final answer on Romex Use ?
- Thread starter patc
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Re: Final answer on Romex Use ?
Man, this is a hot button.... The way I read this it must have a 15 min fire rated concealment on EACH side... So if you had an office with drywall inside and wood exterior OR wood walls and block exterior it would not comply.. And what about the attic??
Man, this is a hot button.... The way I read this it must have a 15 min fire rated concealment on EACH side... So if you had an office with drywall inside and wood exterior OR wood walls and block exterior it would not comply.. And what about the attic??
Re: Final answer on Romex Use ?
As far as most construction materials for walls, ceilings, or floors in a comercial building, they would all have a 15 minute finish rating.
Now the definition of concealed could mean in an attic space or underneath the structure.
Let's imagine an attic space with 5/8" sheetrock for the cieling, 20' above this ceiling is a roof which would meet the 15 minute finish rating, this would meet any interpretation even though it is "concealed" in a large area.
With the exception of being exposed to the exterior, all installations could be concealed if rendered inaccessable by the article 100 definition.
Roger
[ July 08, 2004, 09:17 AM: Message edited by: roger ]
As far as most construction materials for walls, ceilings, or floors in a comercial building, they would all have a 15 minute finish rating.
Now the definition of concealed could mean in an attic space or underneath the structure.
Let's imagine an attic space with 5/8" sheetrock for the cieling, 20' above this ceiling is a roof which would meet the 15 minute finish rating, this would meet any interpretation even though it is "concealed" in a large area.
With the exception of being exposed to the exterior, all installations could be concealed if rendered inaccessable by the article 100 definition.
Roger
[ July 08, 2004, 09:17 AM: Message edited by: roger ]
Re: Final answer on Romex Use ?
In the 2003 IBC, Table 721.6.2(1) gives assigned times for wood structural panel. 15/32-inch panel with exterior glue gets a 10 minute value, while 19/32-inch panel with exterior glue gets the required 15 minute value.
However, I question whether it is the intent of the NEC to provide a thermal barrier from the outside. If other buildings or property lines are near enough to the building in question to pose a fire exposure danger from that direction, the building code will specify the required fire resistance for those exterior walls. My personal opinion is that the thermal barrier requirement in the NEC is concerned with exposure from/to the interior of the building in question.
In the 2003 IBC, Table 721.6.2(1) gives assigned times for wood structural panel. 15/32-inch panel with exterior glue gets a 10 minute value, while 19/32-inch panel with exterior glue gets the required 15 minute value.
However, I question whether it is the intent of the NEC to provide a thermal barrier from the outside. If other buildings or property lines are near enough to the building in question to pose a fire exposure danger from that direction, the building code will specify the required fire resistance for those exterior walls. My personal opinion is that the thermal barrier requirement in the NEC is concerned with exposure from/to the interior of the building in question.
fc
Senior Member
- Location
- New Jersey
Re: Final answer on Romex Use ?
It most commercial office space they have a drop or suspended ceiling so 334.12 (A) 1 would prohibit it's use.
It most commercial office space they have a drop or suspended ceiling so 334.12 (A) 1 would prohibit it's use.
jimwalker
Senior Member
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- TAMPA FLORIDA
Re: Final answer on Romex Use ?
I recently wired an office building in romex.As long as they have hard ceiling no problem.Cost wise it is far cheaper and faster than emt or mc.
I recently wired an office building in romex.As long as they have hard ceiling no problem.Cost wise it is far cheaper and faster than emt or mc.
Re: Final answer on Romex Use ?
I agree its alot cheaper bot is it being applied properly? I agree that an attic may be considered sealed if it is "not accessible" but as soon as they add an air handler up there, does that change everything? What about a storage building with exposed metal truss roof, which is a type III, IV or V construction, can you have open runs accross the truss? So many questions, so little time (I type too slow).
I agree its alot cheaper bot is it being applied properly? I agree that an attic may be considered sealed if it is "not accessible" but as soon as they add an air handler up there, does that change everything? What about a storage building with exposed metal truss roof, which is a type III, IV or V construction, can you have open runs accross the truss? So many questions, so little time (I type too slow).
Re: Final answer on Romex Use ?
Suspended ceilings are already prohibited so that doesn't come to play here.
The bottom line is, common sense would tell you there is nothing wrong if it's concealed in walls, floors, or ceilings period.
Ooops, I forgot, common sense died.
The only reason it can not be used above suspended ceilings in a commercial buildings is it was a trade off with the metal conduit and cable companies when NM was allowed above three floors.
Here's a question, what is the definition of "Finish Rating"? hint; it's in the UL orange books.
Roger
[ July 08, 2004, 06:36 PM: Message edited by: roger ]
Suspended ceilings are already prohibited so that doesn't come to play here.
The bottom line is, common sense would tell you there is nothing wrong if it's concealed in walls, floors, or ceilings period.
Ooops, I forgot, common sense died.
The only reason it can not be used above suspended ceilings in a commercial buildings is it was a trade off with the metal conduit and cable companies when NM was allowed above three floors.
Here's a question, what is the definition of "Finish Rating"? hint; it's in the UL orange books.
Roger
[ July 08, 2004, 06:36 PM: Message edited by: roger ]
Re: Final answer on Romex Use ?
Pat, I was referring to EACH side as concealment. By the way it is worded, I take it as "being surrounded by a 15 min covering and as earlier stated it could be in attic if roof is 15 min rated. I may be off but that is the way I was reading it. It probably could be more clear. What if you had a detached garage. It is not a dwelling by the code. I will take the garage if it is sub fed off the house. Maybe not to the letter correct but I feel that is reasonable. I told ya'll this was a hot button!!
Pat, I was referring to EACH side as concealment. By the way it is worded, I take it as "being surrounded by a 15 min covering and as earlier stated it could be in attic if roof is 15 min rated. I may be off but that is the way I was reading it. It probably could be more clear. What if you had a detached garage. It is not a dwelling by the code. I will take the garage if it is sub fed off the house. Maybe not to the letter correct but I feel that is reasonable. I told ya'll this was a hot button!!
- Location
- Massachusetts
Re: Final answer on Romex Use ?
I do not see how this is tough, NM can be run exposed to sight but not exposed to physical damage.
I know of many brick and steel commercial spaces wired with NM.
The change to the 2002 code that prohibits it from commercial suspended ceilings has changed things somewhat.
I do not see how this is tough, NM can be run exposed to sight but not exposed to physical damage.
I know of many brick and steel commercial spaces wired with NM.
The change to the 2002 code that prohibits it from commercial suspended ceilings has changed things somewhat.
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: Final answer on Romex Use ?
Why would it be any more of a hazard in com. than it is in residential ? Yes it is of lower quaility and not flexable to changes needed but most customers seem to want low price .
Why would it be any more of a hazard in com. than it is in residential ? Yes it is of lower quaility and not flexable to changes needed but most customers seem to want low price .
Re: Final answer on Romex Use ?
Ok here is my humble opinion on this subject. I do not believe that the code allows NM cable to used in structures of type I or II construction unless it can be proved that the building code allowed the structure to be a type III,IV,or V. In type III,IV,or V construction other than residential Multi family dwellings, NM cable would be allowed to be used CONCEALED IN WALLS ONLY. 334.10(A) reads :Type NM cable shall be permitted as follows1)For both exposed and concealed work normally dry locations except as prohibited in 334.10(3).
334.10(3) as read basically states that NM cable must be concealed.334.12A(1)does not allow NM above a suspended ceiling so in my opinion, exposed NM cable in Type I,II,III,IV,or V other than multifamily dwellings is not allowed.
Ok here is my humble opinion on this subject. I do not believe that the code allows NM cable to used in structures of type I or II construction unless it can be proved that the building code allowed the structure to be a type III,IV,or V. In type III,IV,or V construction other than residential Multi family dwellings, NM cable would be allowed to be used CONCEALED IN WALLS ONLY. 334.10(A) reads :Type NM cable shall be permitted as follows
1)For both exposed and concealed work normally dry locations except as prohibited in 334.10(3). 334.10(3) as read basically states that NM cable must be concealed.334.12A(1)does not allow NM above a suspended ceiling so in my opinion, exposed NM cable in Type I,II,III,IV,or V other than multifamily dwellings is not allowed.
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