How do you make a 1-gang into a 2-gang switch box?

We're wiring in some ceiling fans that we had prewired, which means taking down the light fixture and putting the fan up, and then removing the single light switch and wiring in a second switch to the spare red wire in there. There are 2 options, one is to get a 2-button switch that fits in a single gang box....but I plan to eventually put that room's lights on an ALC OnQ switch, which is full sized....so I'd rather expand the single gang box into a 2 gang box and use a separate switch for lights and for fan.

How do I expand a single gang box into enough room for 2? Do I have to somehow carefully rip out the existing box and then put in an old-work 2-gang box? I can't imagine that it would be easy to do, with the single gang box being nailed to the stud, and with electrical wires coming into it. Do I just rip out one side of the box and attach another single gang box to it?

What's the "standard" method? I'd really like to avoid major sheetrock carnage if possible.

I usually rip out the single box and put in an old work double. it's really easy if you just put a flatbar between the box and the stud and pry it away. Remember that since you will be expanding the cutout in the direction you will be prying towards, there is room to get the box out without damaging the sheetrock. It's always been a very clean operation for me.

Hmmm....ok, I guess that makes some sense. I was thinking the wire coming into the box would be an obstacle, but I guess there's enough slack there for the box to move?

You can pickup a little add-on box that slips onto the edge of the existing box at Home Depot for about 50 cents.

Brian

brotsten said:

You can pickup a little add-on box that slips onto the edge of the existing box at Home Depot for about 50 cents.

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I haven't seen those, but I don't know if they would work on the Bakelite type boxes I have. How do they attach?

I haven't had any trouble splitting the Bakelite boxes with some diag. cutters or a saw and prying out the nails. I have never had to repair the drywall.

As long as the power is off, getting the wires out of the box, once the box is loosened, isn't hard. The trick is to make sure the replacement box is "old work" with means it has some type of magic clamping wings tightened from the front and no nails.

I have never seen an add on box that was HV, they are all LV. Are you talking about the Carlon, orange boxes? Those are LV.

Bee, you need two HV ALC switches (one relay, one dimmer). You cant add a HV switch to a lv add-on box. You know that already, just reminding. Its likely best to just add a remodel HV box a few inches away from the existing. It will be very easy to fish the cat5 and the HV to the new box. Make sense?

WayneW said:

brotsten said:

You can pickup a little add-on box that slips onto the edge of the existing box at Home Depot for about 50 cents.

Click to expand...

I haven't seen those, but I don't know if they would work on the Bakelite type boxes I have. How do they attach?

I haven't had any trouble splitting the Bakelite boxes with some diag. cutters or a saw and prying out the nails. I have never had to repair the drywall.

As long as the power is off, getting the wires out of the box, once the box is loosened, isn't hard. The trick is to make sure the replacement box is "old work" with means it has some type of magic clamping wings tightened from the front and no nails.

Click to expand...

I checked, the one I was thinking of was "low-voltage", if that works.

Jbox Addon

Brian

brot, thats what I thought. No, those wont work since he needs to add a HV to the existing HV. Another issue with THOSE boxes with ALC is they are too narrow as the ALC switches are pretty wide. However, I was able to add an ALC (LV Aux) with the add-on box you linked to by putting the LV box in then taking a sawzall and cut off the "sticky" part that adheres to the side of the existing HV box. The amazing part is the new LV box still stayed in place.

(the add-on box clips and also adheres with sticky tape to the side of the already existing box)

Ya, that makes sense. I think I'm leaning towards the pry-bar method, if for no other reason than it let's me buy a pry-bar! I'll give it a few good tugs and see if I can separate it from the stud, and if not, then a few selective cuts with the sawsall will probably make it go. I have plenty of experience with the old work boxes, so that should be easy.

Cut the power first! Got to remember that part....

You'll risk less damage to the drywall if you use a sawzall to cut the nails that are securing the existing 1-gang box.

This is how I've always done it and the way I see electricians do it too.

Once the old box is loose, you will have to wrestle it to get away from the wiring.

Heh...hadn't thought of THAT method. I'll have to take a look at the pictures I took of the area to see just what my sawzall could also damage...nothing is beyond my ineptness.

Didn't you just finish construction! What are you doing tearing stuff out and replacing it already

Well then, I certainly won't be posting pics of me installing the in-wall speakers. It involved removing a good portion of a 2 X 4, and a corresponding large hole in the sheetrock on the other side....

pkoslow said:

You'll risk less damage to the drywall if you use a sawzall to cut the nails that are securing the existing 1-gang box.

This is how I've always done it and the way I see electricians do it too.

Once the old box is loose, you will have to wrestle it to get away from the wiring.

Click to expand...

I second this one. I have done it this way. Just be very careful not to let it get away from you, take it slow (done that too )

Hehe...I know what you mean..I definitely have a love-hate relationship with that thing.