Nail on boxes for unfinished surfaces

[jap]

I see a lot of standard nail on boxes used for portable storage sheds, in attic spaces, unfinished garages, and the like, where they used NMB for the wiring that never will get a finish such as sheet rock or any other covering put on the face of the studs.

Is there any issues using this type of box for this?

Standard plastic plates installed on devices mounted to nail on boxes that don't have a finish flush with the front of the box has never looked right to me, nor, does the opening where the NM pushes into the plastic box that doesn't actually seal around the cable.

When these boxes are installed in a wall with insulation around them and then sheetrock installed on the face of the studs, there's not much chance of anything foreign getting inside the box, which is not the case if these boxes are used where a wall covering is never installed.

Just curious.

JAP>

 

[Dennis Alwon]

334,10 allows nm cable exposed in dwelling and their attached or detached garages and storage sheds.

334.10 Uses Permitted. Type NM, Type NMC, and Type NMS
cables shall be permitted to be used in the following, except as
prohibited in 334.12:
(1) One- and two-family dwellings and their attached or
detached garages, and their storage buildings.
(2) Multi-family dwellings permitted to be of Types III, IV,
and V construction.
(3) Other structures permitted to be of Types III, IV, and V
construction. Cables shall be concealed within walls,
floors, or ceilings that provide a thermal barrier of material
that has at least a 15-minute finish rating as identified
in listings of fire-rated assemblies.
Informational Note No. 1: Types of building construction and
occupancy classifications are defined in NFPA 220 -2015, Standard
on Types of Building Construction, or the applicable building
code, or both.
Informational Note No. 2: See Informative Annex E for determination
of building types [NFPA 220, Table 3-1].
(4) Cable trays in structures permitted to be Types III, IV, or
V where the cables are identified for the use.
Informational Note: See 310.15(A)(3) for temperature limitation
of conductors.
(5) Types I and II construction where installed within raceways
permitted to be installed in Types I and II construction.

 

[jap]

I was more referring to the openings in the boxes not being sealed off, not so much cable.
When the cable is shoved into the box it opens up the clamp which is like creating an opening in box and more times than not the plastic clamp is completely broke out of the box.

At what point do you not allow a 1/2 x 1/2" square opening in an exposed box with energized wiring inside?
or
Is it simply not an issue that needs to be addressed?

JAP>

 

[JFletcher]

I was more referring to the openings in the boxes not being sealed off, not so much cable.
When the cable is shoved into the box it opens up the clamp which is like creating an opening in box and more times than not the plastic clamp is completely broke out of the box.

At what point do you not allow a 1/2 x 1/2" square opening in an exposed box with energized wiring inside?
or
Is it simply not an issue that needs to be addressed?

JAP>

That's the way I see it. If it bothers you or the HO, you can always take a piece of a putty pad and seal the cable entry(-ies).

Although theoretically possible than a box of small nails could fall onto the electrical box, and one could get in and cause a short, I think that's about as probable as a hairpin falling across a partially inserted plug ground down (or a 2 prong). Possible, but not likely.

 

[jap]

you can always take a piece of a putty pad and seal the cable entry

That'd be a "stretch" to 110.12 A.

JAP>

 

[Smart $]

I was more referring to the openings in the boxes not being sealed off...
JAP>

I think you have a better case for the box and wall plate not being used for their intended purpose, i.e. flush mount vs. surface mount.

 

[JFletcher]

That'd be a "stretch" to 110.12 A.

JAP>

That's how the inspectors I've dealt with on commercial jobs asked us to seal plastic boxes with the little flap missing from one of the cable entries. and a piece of putty is more substantial than that tiny flap of plastic connected to the box by maybe a 1mm thick 'post'.

 

[jap]

That's how the inspectors I've dealt with on commercial jobs asked us to seal plastic boxes with the little flap missing from one of the cable entries. and a piece of putty is more substantial than that tiny flap of plastic connected to the box by maybe a 1mm thick 'post'.

Something about "Commercial" and "Plastic Nailon Boxes" to me don't belong in the same sentence.


JAP>

 

[JFletcher]

Something about "Commercial" and "Plastic Nailon Boxes" to me don't belong in the same sentence.


JAP>

Virtually all wood framed hotels 3 floors or less (new con, in the states I've worked) are wired with NM and plastic boxes. If the owner wants conduit for the v/d/v, we do metal boxes. We did plastic boxes and ENT once; never again.

 

[jap]

Virtually all wood framed hotels 3 floors or less (new con, in the states I've worked) are wired with NM and plastic boxes. If the owner wants conduit for the v/d/v, we do metal boxes. We did plastic boxes and ENT once; never again.

No explanation needed on that one.


JAP>