NM Cable in normaly Dry location

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In Article 334.10.A.1 it states NM cable can be used in normally dry locations. In 334.12.B..4 it states NM cable can not be installed in damp or wet locations. I will be wiring a house down south and it is on pillars not a basement. So can I use NM below the house ? Is that considered a normally dry location. It more than likely will get some moisture from fog or high humidity air now and then, but it will never be exposed to any rain.
Thanks DC
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
So can I use NM below the house ?
It really depends on where you are, and you should ask your permit issuer and/or inspector before wiring. In one county here, under-porch and sunroom space may be in NM, another county requires UF.

To me, crawl spaces and even attics are subject to as much airborne humidity as open under-floor areas like this. Building code requires insulated joists bays under living spaces to be enclosed/covered.
 

ceb58

Senior Member
Location
Raeford, NC
Never had any problem using nm in crawl spaces. The building codes require a vapor barrier installed under the house. Most of the crawl spaces are bone dry. You state the house will be on pillars. But will it have a solid foundation around the outside?
 
Never had any problem using nm in crawl spaces. The building codes require a vapor barrier installed under the house. Most of the crawl spaces are bone dry. You state the house will be on pillars. But will it have a solid foundation around the outside?
The home is on pillars that are 3 feet high and it is not enclosed.
 

ceb58

Senior Member
Location
Raeford, NC
The home is on pillars that are 3 feet high and it is not enclosed.

What southern location will you be working in? I wired one house that was located in a 25 year flood plain. They had to leave drain ports in the foundation and the piers had to be 8'' higher than normal code but I had no problem using nm. Your best bet would be to contact the AHJ for their ruling before starting. If they rule no nm its still not that big of a deal. Pull every thing streight through the walls or overhead in the attic space. Then anything that had to go in crawl space run uf.
 
The Home is in Louisiana. From what I can see they are still under NEC 2005 with no admendments.
I have considered UF cabel, but when I read article 334.10.A.1 and it states normaly dry : that to me sounds like it may be exposed to some limit of moisture some time.
 
I think that sums it up. According to the location, damp- definition and article 334.12.B..4 and 2005 code with no amendments it is not in code compliance for using NM cable in this application.
Thanks for clearing it up for me.
DC
 

macmikeman

Senior Member
Its been the norm here for 50 years to wire underneath houses in the crawl space with nm cable. To be honest, some staples get rusted, hardly ever to the point of total dedigration and release of cable. The interiors of the cable sheath are not affected to any degree at all, and the cable is as good as the day it was installed. Calling it a damp location is baloney in my book, but call it what you like.
 

zappy

Senior Member
Location
CA.
No comprende

No comprende

Ok NM-B or NM is the same thing correct. UF and NMC are the same thing also? If they aren't, I don't think I have seen NMC before.
 

zappy

Senior Member
Location
CA.
No comprende

No comprende

Ok NM-B & NM is the same thing correct. UF and NMC are the same thing also? If they aren't, I don't think I have seen NMC before.
 
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