The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Sprinklered equipment 26-008
by twh
Today at 06:28 AM
On Delay Relay with Auto Reset
by Potseal
Yesterday at 09:59 AM
Wow, that was close!
by jraef
11/28/16 07:06 PM
Earthquake in New Zeeland
by RODALCO
11/27/16 11:25 PM
Calling all Non-US members!! (Non-US only)
by Tjia1981
11/27/16 06:33 AM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 15
HotLine1 10
Trumpy 8
Texas_Ranger 8
sparkyinak 7
Who's Online
0 registered (), 192 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Page 1 of 3 1 2 3 >
Topic Options
Rate This Topic
#182611 - 12/04/08 12:19 PM Is a block wall "wet"?
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
This came up in another "homey" forum.

Is the inside of a free standing block wall a "wet location"?

How about the inside of the exterior block wall of a building?

What is the difference?

I have no real opinion. I can make a case either way.
_________________________
Greg Fretwell

Top
2014 / 2011 NEC & Related Books and Study Guides
#182612 - 12/04/08 01:53 PM Re: Is a block wall "wet"? [Re: gfretwell]
George Little Offline
Member

Registered: 01/18/04
Posts: 1492
Loc: Michigan USA
Greg- I think reading the definitions of "wet" and "damp" locations says it pretty well.
There isn't any mention of block wall(s) as being either wet or damp. So I guess they are dry?
My opinion is that a block wall is not a wet location.
_________________________
George Little

Top
#182615 - 12/04/08 03:12 PM Re: Is a block wall "wet"? [Re: George Little]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6804
Loc: Brick, NJ USA
Greg:
Is the free standing block wall capped?

Seriously, I have to go along with George. That's twice in two threads!
_________________________
John

Top
#182616 - 12/04/08 05:31 PM Re: Is a block wall "wet"? [Re: HotLine1]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
I do not believe a 'block wall' is always a wet location.

Code does say that a masonry or concrete wall, in contact with the earth - such as a basement wall - is a wet location.

A freestanding wall, such as one that might be built to fence off a patio, would be a wet location IMO.


Edited by renosteinke (12/04/08 09:51 PM)

Top
#182619 - 12/04/08 05:59 PM Re: Is a block wall "wet"? [Re: renosteinke]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6804
Loc: Brick, NJ USA
Additional thought:
Interior side of an outside block wall IMHO is dry, under normal conditions.

Any wiring 'within'/'inside' basement walls in direct contact with earth, by definition is a wet location. Wiring methods on the interior surface should comply with dry locations; or in some instances possibly 'damp locations' due to condensation moisture.

As to a 'free standing' masonry wall, that's a 'judgement' call. George said block is not mentioned in the NEC. Reading ('08) wet locations, I now have to differ with him. 'Block' is IMHO opinion understood to be made of masonry/concrete.

Sorry George, I now only agree with you in one thread.
_________________________
John

Top
#182628 - 12/04/08 09:36 PM Re: Is a block wall "wet"? [Re: HotLine1]
leland Offline
Member

Registered: 08/20/07
Posts: 856
Loc: Lowell area, Ma. USA
My opinion (not that you care)

Free standing block wall seperating 2 patios (or the like) outside.Exposed to weather.
Either inside or outside the blocks,capped or not, Wet Location.

Top
#182631 - 12/04/08 09:49 PM Re: Is a block wall "wet"? [Re: leland]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
I knew this was going to be a split decision. I have also never got a good answer as to why an exterior wall of a house is dry, right up to and including the canopy of a jelly jar luminaire.
I know there is supposed to be a seal between the luminaire and the wall but the bugs I see in them seems to tell me this is far from perfect.
We can't even keep water out of a Bell box.
_________________________
Greg Fretwell

Top
#182643 - 12/05/08 08:31 AM Re: Is a block wall "wet"? [Re: gfretwell]
George Little Offline
Member

Registered: 01/18/04
Posts: 1492
Loc: Michigan USA
First of all, I've concluded that Greg is a trouble maker.:) And most of us inspectors are trouble makers.
Hotline1, (John) I looked in the '08 and the wording is the same as the '05 for definitions of "wet" and "damp" locations. I am wrestling with the fact that you claim a slab of concrete and a poured wall are the same thing as a concrete block or a cinder block wall. I have seen block walls that were wet/damp but that's a building issue. I guess like it says in "damp locations", some basements could be considered damp but they are basing that on a concrete poured wall. I look at the hollow core of a block and the fact that the code does not mention block walls and that's why I stake my claim.

Maybe we can disagree on this one:)
_________________________
George Little

Top
#182646 - 12/05/08 10:14 AM Re: Is a block wall "wet"? [Re: George Little]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
Let's open up the question a little.

Can Romex be run inside a block wall at all? Even when the wall is in a 'dry' location?

Article 334 has some interesting twists to this question. First of all, it differentiates between different types of masonry construction. It lumps 'wet' and 'damp' locations together. Perhaps, most importantly, it differentiates between "NMC" and the other typs (NM and NMS).

Mind you, "UF" is none of these, and has its' own section. (A side note: UF can be run in masonry, but not in poured concrete).

What are the differences between NM, NMC, and NMS? I was given to understand that the first is the old cloth-covered stuff, and thet the last has yet to be produced. Is this correct? How can you tell them apart in the field?

Top
#182651 - 12/05/08 10:41 AM Re: Is a block wall "wet"? [Re: renosteinke]
SteveFehr Offline
Member

Registered: 03/19/05
Posts: 1192
Loc: Chesapeake, VA
334.19(B) specifically allows NM to be installed in the cavities of block walls in normally dry locations.

Basement block walls, freestanding unfinished walls, etc, are not dry. But if the block wall is above ground, covered by a roof, and protected from the weather by siding or brick (etc), then it's a dry area. Why wouldn't romex be allowed in it?

(FYI, 334.2 defines NM, NMC and NMS :))

Top
Page 1 of 3 1 2 3 >



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals