Box Fill, 7.5 and 8 cu. in., 14/2 with device question

[mfiene]

I am doing some old work and the outside walls only allow a 1.5" deep box. There are 1.5" deep boxes but using 14/2 and a device appears to violate the box fill requirement of section 314.16(b).
14/2 w/GND = 6 cu in
device= 4 cu in
total = 10 cu in

Oddly enough, one manufacture of steel boxes stated that you should count the device as one conductor, not two.
What are these boxes designed for. The metallic boxes I found are 7.5 cu in and the plastic box I found is 8 cu in.

mfiene@comcast.net

 

[jimwalker]

Re: Box Fill, 7.5 and 8 cu. in., 14/2 with device question

First the device does count as 2
Now choices that are open
1. you can chip out concrete or break the block ( if you do not have a chipping hammer you could drill severall holes and use chisel)
2.they do make plastic box's that are 1 1/2 x4x4 and you put a plastic mud ring on them(it counts as cubes too and will be stamped)
3.Sometimes you will need to make these as only one 14-2
4. the min.you will have is 10 cubes.
5. The 8 cube box would be for old non grounded receptacles.
Not sure if that helps but you can't break code.
If this is block try to find the hollow cell by tapping with hammer or drill some small holes
Do not forget to use foam to fill the hole around the box

 

[mfiene]

Re: Box Fill, 7.5 and 8 cu. in., 14/2 with device question

The outside wall is double brick.

 

[tonyi]

Re: Box Fill, 7.5 and 8 cu. in., 14/2 with device question

There is a square cornered handi-box format that's 11.5 cubes. Not too common though.

Another option is to ditch the gnd wire and use a 14-2 AC cable where the armor provides the ground.

Somewhat uglier and costlier, but workable, is to mount the low cubes box, then install a wiremold surface box over it. With the price of wiremold stuff, you might be better off getting a coil of AC for the drops through the wall.

If its mostly adding recepticals, you might consider going with a shallow 4-square and just putting in quads. There's enough volume in one of those for two devices and a 14-2 Romex coming in.

 

[jimwalker]

Re: Box Fill, 7.5 and 8 cu. in., 14/2 with device question

Then start drilling
Don't think i would risk chipping
Did find one box that is 1 1/4 inches deep 4x4 plastic, but this sounds like you can't have a patch.Hope you took this on T&M
I kind of enjoy rewires ,they are a challenge
Give some thaught to making them quads,might gain a few cubes
See i was beat on the quad idea
wiremold Hold that idea for last in if you do there is no problem over fill anymore

[ January 11, 2004, 12:41 PM: Message edited by: jimwalker ]

 

[mfiene]

Re: Box Fill, 7.5 and 8 cu. in., 14/2 with device question

Just to make things even more difficult, the walls are plaster and lath.

 

[jimwalker]

Re: Box Fill, 7.5 and 8 cu. in., 14/2 with device question

Never said rewires were easy.
I am lucky in that i am a plasterer as well as a sparky.
Now theres a nice thing to bring up that deals with EC contracting not NEC .Can we legally do patch work and touch up paint ?
Here the answer is NO
Yet we are allowed to be carpenters!!!
Not you union guys LOL

[ January 11, 2004, 01:25 PM: Message edited by: jimwalker ]

 

[tonyi]

Re: Box Fill, 7.5 and 8 cu. in., 14/2 with device question

The plaster/lath shouldn't be a problem with a metal box. There's two reasonable approaches - tapcon with a new work box, or holdits and an old work box.

In this case, I think I'd go with the tapcons.

How the plaster is opened up will be different for holdits versus new/tapcon. If you go with a holdits, you only want to cut out one full lath and notch the two on either side of it. This will give the plaster ears something solid to rest on and the holdits something solid to grab in the back. Its a common mistake to cut out two full lath - then the plaster ears and holdits are mostly grabbing on the remains of plaster keys and the box can come loose in the future. If you go the tapcon/new route, then sectioning two full lath isn't an issue and will go quicker than notching. A small exploratory hole in the vicinity of where the box is going will locate the laths before the serious cutting begins. Take it slow, maybe use a rotozip. Too much vibration will start busting off plaster keys and then the wall will have seperation/cracking problems.

 

[jimwalker]

Re: Box Fill, 7.5 and 8 cu. in., 14/2 with device question

Love Tapcons
Tell us exactly the makeup of this wall starting with the painted finish.

 

[speedypetey]

Re: Box Fill, 7.5 and 8 cu. in., 14/2 with device question

If the customer is not against it I will suggest to them a 1900(4" sq.) box with a two gang ring and install a quad outlet(2- duplexes). This way there is no patching and they get the benefit of more receptacles.

 

[jim sutton]

Re: Box Fill, 7.5 and 8 cu. in., 14/2 with device question

RACO makes a 1 gang box that is 1.5" deep that is 11.5 ci. RACO #650

 

[jimwalker]

Re: Box Fill, 7.5 and 8 cu. in., 14/2 with device question

Am a bit curious where your running the wire.
Is this more like 2 walls made out of old red bricks ?

 

[mfiene]

Re: Box Fill, 7.5 and 8 cu. in., 14/2 with device question

The outside wall is two bricks thick, then a 2x4 on its side, then the lath and plaster. The wire is pulled between the brick and the wall, tight fit. Had alot of fun doing that pull from the basement to the attic. Had to work around the existing knob and tube wiring. The tap offs on the knob and tube consisted of soldering and wraping the joint with friction tape. Still in good shape after all these years. I estimate that the knob and tube was installed in the 1920's. One light fixture was mounted to the lath with no ceiling box; bare wire was showing.

On the two 8 cu in boxes I can add an extension ring to get to 10 cu in. I found a 1 15/16" deep handy box that has a total of 17 cu in which will help me with the two 12/2's and a receptacle. I'm going to get the Tapcons for the outside wall mounting. I'll probaly mount plaster ears to the handy box when I use them for the inside walls.