Fire hazard?

[jmarkwolf]

When I wired my new shop, I located all the boxes with the little built-in "nubs" that space them out from the stud properly for 1/2" drywall.

I've since decided I'd like to install 19/32" (nearly 5/8") T1-11 for interior wall covering.

This means that all the wall plates will "stand out" from the box about an 1/8" more than intended, exposing some wood to possible arcing and sparking.

This strikes me as a possible fire hazard.

Am I over thinking this?

Are there "special" outlet and switch plates that handle this issue?

Should I bite the bullet and relocate the boxes out from the stud a little more?

 

[ThomasP]

If your devices are "arcing and sparking", you have a much bigger problem on your hands.

 

[Charles (in GA)]

Since you are installing in a combustible material, NEC 314.20 requires that the boxes be mounted flush with the surface, so the face plates will draw down on the box and device properly. In NON-combustible materials, such as sheetrock, tile, etc, the box is allowed to be recessed as much as ¼" (which is a poor practice, and looks crappy).

Charles

 

[alfredeneuman]

Use 1 of these:
http://www.amazon.com/dp/B000GAQE9A/?tag=atomicindus08-20

They're UL listed, and available at HD

Here's a Youtube Vid on how to install them

 

[jmarkwolf]

Use 1 of these:
http://www.amazon.com/dp/B000GAQE9A/?tag=atomicindus08-20

They're UL listed, and available at HD

Here's a Youtube Vid on how to install them

Thanks Alfred

That's what I was hoping to learn.

I'd actually seen them at the store but didn't know what the application was.

 

[joe_padavano]

It appears to me that those box extenders significantly reduce the available volume inside the box. If the box is filled to near capacity, this will become an issue. Perhaps you can trim them if you're only needing to extend a fraction of an inch or so.

 

[Blk88GT]

I can't see how trimming them would still pass code, but it would certainly work in the case you're describing.

 

[joe_padavano]

I can't see how trimming them would still pass code, but it would certainly work in the case you're describing.

The overfilled box shouldn't pass code either. In any case, If you trim them to the point that there is still the same minimum overlap to the original box that the design allows (since the extender is designed to accommodate a range of wall covering thicknesses), how does that change the functionality of the extender? The OP is only talking about 1/8" or so of required extension, and these things accommodate 1.5" of extra thickness.

 

[alfredeneuman]

They're so thin that they don't have an appreciable effect on the volume of the box.


They're allowed to be trimmed and not violate the listing.

 

[joe_padavano]

They're so thin that they don't have an appreciable effect on the volume of the box.

Got it. The picture on Amazon makes them look pretty thick, but this spec sheet proves otherwise.

 

[tfi racing]

Sheet metal box extenders are also available if you prefer.

 

[alfredeneuman]

The steel ones aren't UL listed, at least in the US

 

[Rock knocker]

The steel ones aren't UL listed, at least in the US

Thomas Betts and Gavin both make steel extensions available in the US. The Gavin product is stated to be UL listed on their site, while I find it hard to believe that TB would sell an item in the USA that was not listed if applicable

 

[alfredeneuman]

Thomas Betts and Gavin both make steel extensions available in the US. The Gavin product is stated to be UL listed on their site, while I find it hard to believe that TB would sell an item in the USA that was not listed if applicable

You're right! I stand corrected