Wet/Damp Location

[e1coxjck]

Is an exterior masonry/brick wall considered a wet/damp location? How about the 1" air space between the masonry and insulation? Gist of question is the use of sheet steel boxes in exterior walls and the use of gasketed cover plates on these boxes. Brick/masonry exterior walls are porous have weep holes and are therefore I would think at least a damp location. Sheet steel boxes are not water tight and do not mate well with gasketed cover plates. Gasketed cover plates do not provide a watertight seal on porous masonry surfaces. Would the NEC require a weather/water tight box for this application? Standard practice seems to be a sheet steel box with a weatherproof outlet cover which I do not think meets he NEC requriements for a wet/damp location.

 

[Pierre C Belarge]

Based on your explanation of the construction of the wall, this is an interesting question.

At the Eastern Section IAEI Meeting this past week, a similar question was addressed by CMP members and the general attendees.

When one installs a box within the exterior wall of a building, the interior of the wall cavity itself is not a wet/damp location, and standard wiring methods for dry locations can be installed.

If you have a personal concern for deterioration of the products after installation, you can address that as per your concern. Remember, installing to the code is the "worst job one can do to meet the minimum installation requirements" (the italized wording is mine).

BTW: welcome to the forum!!

 

[e1coxjck]

Thanks for the quick reply. Do you have any thoughts on the use of the gasketed coverplate on the exterior wall. Given the construction of a sheet steel box will the gasketed coverplate mate with the box properly to form a watertight seal?

 

[Dennis Alwon]

On uneven surfaces such as brick I usually don't have much of an issue with the gasket sealing however sometime it can be a problem and I will use silicone to fill the gap.

 

[Dennis Alwon]

Years ago in Durham, NC they would make you either sleeve a piece of nm cable going into a disconnect outside or you had to use UF. Brick will absorb some moisture but I am not sure I would call it a wet location if a box is installed in the brick. I have used masonry boxes, plastic boxes and standard metal boxes without any problems. If the area around the brick is sealed it should not be an issue- hence silicone again around the perimeter of the box.

 

[ericsherman37]

I just babysat some bricklayers yesterday! We used regular steel masonry boxes on the interior. But we don't have much going inside the walls; the building is going to be for the Aquarium Science department of the local community college, so most of the stuff is supposed to be exposed so they can change things around fairly easily. Like if they have a new shark donated or something and need to install a big ol' tank for it.

On the exterior walls, we had some leftover custom-made stainless steel masonry boxes from a previous job that we used. You might not have that benefit :grin: I don't see what's wrong with the "industry standard" kind of installation for this scenario.