Putting in single light switch into 2 gang gem box

[Mikepier]

Doing some electrical work in my brother-in-law's condo. Because of a wall that was taken down, I have to make a splice box to rejoin some circuits. One of which was a light switch for the hallway.This will be in a sheetrock wall so I have to cut in an old work gem box The only problem is one gem box is to small to fit 4 BX cables, so I wanted to put 2 gem boxes. But now how do I put in only 1 light switch? Is there a cover plate made for that purpose? Or am I missing something here?

[gfretwell]

You can get decora covers and put a blank on one side

[aemeijers]

A real electrical supply will have 1 switch/1 blank. Borg will have the overpriced snap-together modular cover plates. In situations like that, I often see a blank covered box high on the wall, painted wall color. Or if there is a nearby closet, hide the J-box in there. In a house, you can just put it in the attic- I assume that is not an option here.

[hrhofmann]

Can you fit a duplex outlet into the double box in addition to the switch? Outlets mounted up high are not normal, but they sure are handy to plug in a vacuuum cleaner without having to bend over and reach behind some piece of furniture.

[RBM]

** Raco actually makes a thing that replaces one of the sides of the gem box, which adds additional space and sits behind the sheetrock. I think it's called xcube. This won't solve your problem of getting 4 BX cables into a box through a 2x3 cutout. If I were you, I'd cut open the sheetrock 8X8 and install a deep bang on 1900 box with a single gang reducing cover, then patch the sheetrock. It'll be neater, easier, look like it should, and be legal

[Reed]

do a Google search for

Leviton 80506

see if that is what you want (2 gang, 1 toggle, 1 blank)

[John Grabowski]

*An electrical supply company will have two gang toggle/blank wallplates in stock. If they don't have the color that you want, it can be special ordered.

RBM made a very good suggestion. With a 4" square x 2 1/8" metal box you will have plenty of splice room and you can just put a mud ring on for a single device.

I hope that we will see some before and after pictures of this condo project.

[Mikepier]

Thanks for everyones inputs.

Because of the length of the BX's and the location, I can't mount the box high, nor can I re-run some of them because they continue into the walls feeding the outlets. I would have to break the old plaster/ sheetrock walls to gain access to the cables. Also I did not want to cut out an 8X8 in the wall to put a 1900 box with a mud ring. Putting in 2 old work gem boxes seem like the easiest solution. But at least I know they do make a 2 gang plate that has one side blank, or as one suggested put in an outlet and a switch.

[jw]

This is what you need.

's called a plaster ring. You mount your double (4 inch) box deeper in the wall, then add this plaster ring. The lip on the front is the only part that sticks out of the wall. You can buy them with "lips" from 1/4" to 3/4". If you're using 1/2" sheetrock, you want a 1/2" lip.

Most bigger hardware stores have them, or go to an electrical supply house.

The one shown in the picture has a 1/4" lip, which is for paneling.

This one has a 5/8" lip, which would work fine for 1/2" sheetrock, just put your box back another 1/8". (Most of your switch will be set into the lip, so you will have lots of space in the box itself).

This is what the pro's use and have used them for many years. If you got BX cable, you MUST use a metal box to preserve the grounding. Then use this metal plaster ring.

You can also buy these as "doubles", for two switches, or outlets, or one switch and one outlet next to each other.

[RBM]

He doesn't want to open the wall to mount a 1900 box, so he's using cut in gem boxes

[Nate Nagel]

there is such a thing as an old work 1900 box, believe it or not - but I don't know that there's any good way to combine it with a plaster ring.

There's another version that has the screw holes in the same place as a regular 1900 box, which is great for fire alarm speakers in retrofits. (that's why I knew about it.) But my google-fu is failing me right now.

I think the solution to the OP's problem would be to use a 2-gang gem box, and buy a "switch blank" and a double switch plate (or a plate w/ one toggle and one blank, if such a thing exists?) OR else just give up and open the wall and use a 1900 box w/ plaster ring, and deal with the resultant patching and painting. Personally I would be tempted to do the latter, 'cause I'm anal retentive.

doing the wire fill calcs... 4x 14/2 plus 1 for ground, 1 for clamps, 2 for a yoke requires 2 in^3 per conductor = 20 in^3 so a 1-1/2" deep 1900 box (21 in^3) barely has enough volume. (plaster ring will add a slight amount of volume) a deeper two gang box would likely make wiring easier but then you're back where you started with ending up with an unattractive large switch plate.

nate

[Mark Lloyd]

[snip]

I had that idea too. I know someone who did that in the attic.

[snip]

[RBM]

A double gang cut in (old work) gem box is what he's using. In your fill calcs, no ground wires, it's BX

[Nate Nagel]

It sounded like he hadn't cut it in yet. I know 1940's BX didn't have ground wires but didn't BX gain ground wires the same time that grounding became required? I know that if I go to the Home Improvement Emporium and look at a roll of "AC cable" it will have a ground wire as well as the bonding strip

nate

[RBM]

**Even in the 20's grounding was required for things like light fixtures, under certain circumstances. Even in the 20's you could buy Romex cable with ground , just for that purpose. The armor of type AC cable (BX) serves as it's ground. It probably has always been available with a copper grounding conductor, although I've never seen it. When you go to Home Depot, you're probably looking at type MC lite, which has a green grounding conductor. I don't believe they even sell AC cable

I know that if I go to the Home Improvement

[Mikepier]

de quoted text -

I have already cut the box in. And as for the BX's, 3 of them are 14/2 original wiring to the condo, steel clad no gnd, and 1 of them is new

14/2 MC lite with Gnd,

[jw]

Then he should get the extra deep ones. Standard are 2.5", but they make deeper as well as shallower ones. Get the deepest that will fit in the wall, gang two of them, and put an outlet next to the switch. They always come in handy for something anyhow. Of course they do make cover plates where half the box is covered with a blank, but if it was my job, I'd add the outlet.

[N8N]

I don't think a 3.5" single gang box - deep as you're going to find, and as deep as will fit in a typical wall - will fit all the cables he has. So really he's still got the same two options as originally stated - either double gang or 1900 w/ mud ring.

BTW, it seems that these days by the new wire fill calcs, you pretty much have to use a 3.5" deep box everywhere now, except for a wall switch on a switch leg, to remain legal.

nate