Receptacle Boxes secured to Sheathing?

[Uncle Bob]

Tool and die Industrial building add on. The surface mount receptacle boxes along the interior wall are secured to metal sheathing with bolts and nuts; not to the framing.

Code section please; 2005 NEC.

Uncle Bob

 

[480sparky]

314.23(a).

 

[fatboy]

manufacturer's spec's? listing?

 

[peach]

yeah, sparky.. if any of anything else we can find "with other provisions of this section shall be provided" Article 314 goes to 314 (F).. 4 pages or so.. in an almost un-understandable code....

 

[Uncle Bob]

Sparky,

Thanks, the NEC is a bad as the other codes; when it comes to making requirements a judgement call.

2008 NEC

"314.23 (A) Surface Mounting. An enclosure mounted on a building or other surface shall be rigidly and securely fastened in place. If the surface does not provide rigid and secure support, additional support in accordance with other provisions of this section shall be provided."

I can rigidly and securely fasten an enclosure to a cardboard box. Unfortunately, the electricians around here feel the same way.

Since these receptacle boxes are going to be used in an industrial building; I think I'm going to leave the call to the owner.

Personally, I wouldn't want a surface mount receptacle box secured to gypsum board (sheetrock) in my home; and it isn't going to get as much abuse as it will in this building.

Wasn't the NEC originally printed to provide "good working practices" for electrical installation?

Thanks again for the section,

Uncle Bob

 

[peach]

don't allow surface mount anything... it only takes me sticking my tester into a receptacle to tell that the receptacle or device isn't solidly mounted.. to anything.. (recently pulled the entire device out of a wall.

 

[480sparky]

So you don't care for this?:

 

[peach]

assuming the plywood is secured to the structure, and all conduit and boxes are secured to the plywood, this is probably ok.

Having almost pulled a receptacle thru the drywall when I removed my tester, I'd say it wasn't properly secured. .... somebody else did the close in inspection.

I'd question this particular installation as compliant with the interior finish provisions of IBC.

 

[480sparky]

There's probably about 30-40 tapcons in each sheet of plywood, and all the pipe & boxes are fastened with 3/4" long tek screws. I'd venture to say a gorilla would really have to work at it to remove the plywood.

 

[Uncle Bob]

Sparky,

This is in a manufacturing facility that uses many plug-in, hand-held power tools. My concern is with a metal sheathing that is very flexible; like you see on a steel shed. When you plug or unplug power equipment into the receptacle; the sheathing will bow and give in both directions. This is not stable and with continued use; the receptacle box will either come loose from the sheathing or stress the sheathing screws until the sheathing comes loose from the framing.

It's a call for the building official to make; and, that should be as limited as possible; because that will make it a local requirement; while we are attempting to consolidate all code requirements.

It's a shame that many contractors will attempt to use the easiest methods without regard for the stablility of the end results.

Later, I will be providing pictures of the numerous, unquestionable, non-code compliant construction work that is going on around here. There are major builders within this State that have never; and don't now, use anchor bolts in residential construction to secure the sill plates to the concrete foundation. What make it worse; is that they have never heard of many code requirements that have been in place for 10 to 20 years.

It's freaking scary,

Uncle Bob

 

[480sparky]

My gut reaction is that it's not secure. If I can manually move a box, it's not mounted correctly. Granted, there are some exceptions (such as a box mounted in a T-grid ceiling), but on a wall, the box should not move.

 

[chris kennedy]

UB, have you checked the cut sheets from the manufacture of the sheathing? Dollars to doughnuts they spec load types that can be fastened to it.

 

[BSSTG]

Geeez you guys are tough. I thought bolts w/nuts would be ok unless it's just obviously a crappy wall.

BS

 

[chris kennedy]

Geeez you guys are tough. I thought bolts w/nuts would be ok unless it's just obviously a crappy wall.BS

If the plumber screws up, mop it up, if the finisher screws up, scrap and mud, if mechanical screws up, install more AL tape, if I screw up, something burns or someone gets hurt. Thats not an option. You say tough, I live anal.

 

[Uncle Bob]

The code section Sparky gave me was the answer to my question. When you plug and unplug a cord; the wall moves both ways; and eventually either the sheetmetal wall will come loose from the framing or the box will come loose from the wall. So they are going to have to install the boxes "ridgidly and securely"; per 314.23 (A).

Ya'll are what makes this forum valuable,

Thanks,

Uncle Bob