# trimming back plastic electrical boxes?



## Marson (Jan 26, 2018)

Multitool works good for this.


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## chandler48 (Jun 5, 2017)

That box is adjustable front to back. Unless you have it jammed in behind, you should be able to turn the screw on the side and move it in and out.


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## jbrah (May 29, 2018)

chandler48 said:


> That box is adjustable front to back. Unless you have it jammed in behind, you should be able to turn the screw on the side and move it in and out.


Yes, but that will bring the entire box out, so the angle will still remain.

Or are you saying, slide the box out to make it easier to trim square to the wall, then slide the box back so it's roughly flush with the wall?


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## chandler48 (Jun 5, 2017)

No, turn the screw to push the box back in the wall. You are only talking about 1/4" or so. It won't leave a gap and you can use longer screws and spacers for your receptacles/switches if needed. We call these spacers "legos", and they work great for proper spacing. https://www.homedepot.com/p/Ideal-Spacers-5-Pack-772453/202937113


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## Colbyt (Jan 27, 2014)

1/8" or less will usually be covered by the finish plate.


Make sure the device screw points are deep enough before trimming.


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## jbrah (May 29, 2018)

chandler48 said:


> No, turn the screw to push the box back in the wall. You are only talking about 1/4" or so. It won't leave a gap and you can use longer screws and spacers for your receptacles/switches if needed. We call these spacers "legos", and they work great for proper spacing. https://www.homedepot.com/p/Ideal-Spacers-5-Pack-772453/202937113


Got it, thanks! 

Since the box would be recessed and at an angle, the outlets would also be at an angle relative to the drywall, but it looks those plastic spacers can be trimmed asymmetrically (turning them into angled shims) so that the outlet mounts square to the drywall.

This is a much better solution than trimming the boxes as I was initially thinking because not only does it save the work of trimming, but even if I trim the front edge of the boxes to make them square to the drywall, the screw points on the box for the outlets will be at an angle, causing the outlets to be angled relative to the drywall.


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## CodeMatters (Aug 16, 2017)

Outlets should not be fastened against boxes. When the drywall is cut properly 
(tight to the box) the device ears should pull up against the drywall before reaching 
the box which is ideally recessed ~ 1/8". 
No need for spacers unless the drywall has been cut too large, which isn't the case 
in your pics.


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## Old Thomas (Nov 28, 2019)

I prefer to have the boxes flush with the finished wall so I can fasten devices tight to the boxes. Our FL house had the boxes recessed 1/8" to 1/4" and the receptacles were all loose. After the previous owner had wiggled plugs around to get them out the ears on the receptacles gave a little and let the receptacles move around. Tightening them made them too recessed for the cover plates. I took the receptacles out and put small washers between the receptacles and boxes so I could screw them down tight and they don't move. Recessed boxes make it easy, but they doesn't perform well over the long term.


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## jbrah (May 29, 2018)

chandler48 said:


> No, turn the screw to push the box back in the wall. You are only talking about 1/4" or so. It won't leave a gap and you can use longer screws and spacers for your receptacles/switches if needed. We call these spacers "legos", and they work great for proper spacing. https://www.homedepot.com/p/Ideal-Spacers-5-Pack-772453/202937113


So turns out I can barely sink these boxes further in. At first I was confused, then I remembered I had slipped a piece of foam board behind the boxes and then spray foamed the back of these boxes. So pushing boxes further back won't work.

I mounted a couple of receptacles to see how far things are off.

side view:









top view:









side view with cover:









top view with cover:









cover not flush with receptacle on side where box is flush to wall









I guess I can try to trim box so it's flush with wall. As I'm envisioning it, this would entail:
1. pull box as far out as the adjustment feature allows, so that cutting box face doesn't damage drywall
2. trim box face using dremel cutting disk so box face will be slightly recessed when I drive box back in
3. at this point, the face of the box will be flush with wall, but the screw holes will still be at an angle to the wall instead of perpendicular. So the receptacles will sit at an angle. 
4. Take those spacers/legos/caterpillar shims and cut them at an angle to offset the angle the receptacles are sitting at. But I don't think this will solve the problem because while the angled spacer will limit the how far the outlet will be driven in on the thick side of the spacer, it doesn't change the fact that the screw holes are angled relative to the wall. So the receptacle will still be angled. Not sure I'm thinking this through properly.

This is the style of box I'm using, in both 1-gang and 2-gang flavors.









If anyone has ideas, I'm all ears!


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## chandler48 (Jun 5, 2017)

Unscrew the box until it releases from the yoke. Then trim the excess foam and whatever else you put back behind the box away. Reinstall the box in it's yoke and screw it flusher.


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## jbrah (May 29, 2018)

chandler48 said:


> Unscrew the box until it releases from the yoke. Then trim the excess foam and whatever else you put back behind the box away. Reinstall the box in it's yoke and screw it flusher.


Didn't realize the box releases from the yoke, thanks. 

Seems I'd still have the problem of the box being at an angle, which means receptacles at an angle. Which probably also means cover plate at an angle, so it won't sit flush against the wall.


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## chandler48 (Jun 5, 2017)

Once you get the box recessed, you can deal with the aberrant receptacles individually.


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## jbrah (May 29, 2018)

chandler48 said:


> Once you get the box recessed, you can deal with the aberrant receptacles individually.


Is recessing the box functionally the same as trimming the face to make it flush with the wall? Because trimming would be a lot easier that trying to cut off foam at the back through such a small opening.

Curious to hear how you'd deal with the receptacles. Whether box is fully recessed or recessed by virtue of cutting off the protruding portion of the face, the screw holes are still at an angle, so the receptacles have to follow that angle, no?

Another option would be to unscrew completely removing the box, then stick in an old work box. That would have the benefit of being perfectly flush and square since it references off the wall, not the stud.

Next time I have to do this, I'm buying metal boxes and a laser level. Any savings I had from using PVC boxes and not using a laser level have been swamped by frustration alone.

Edit: just occurred to me that there's enough play between outlet's screw tab(?) and the screw, that I could use those shims you mentioned earlier, cut at an angle, to get the outlet to sit at an angle relative to the box (i.e., square to the wall). Was that where you were going?


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## Colbyt (Jan 27, 2014)

jbrah said:


> Seems I'd still have the problem of the box being at an angle, which means receptacles at an angle. Which probably also means cover plate at an angle, so it won't sit flush against the wall.





See the post above where someone said,"the device ears tighten down to the drywall and not the box".


You may need to fill voids to at the top and bottom to make that happen.


Washers stacked and longer screws does the same thing and while frustrating may be the easier choice.


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## joe-nwt (Jul 15, 2020)

Colbyt said:


> See the post above where someone said,"the device ears tighten down to the drywall and not the box".
> 
> 
> You may need to fill voids to at the top and bottom to make that happen.
> ...


Another trick instead of using washers is to coil a piece of #14 bare copper wire around a phillips screwdriver to fabricate a coil to slip over the receptacle screw. Cut the coil a bit longer than what you need to hold the receptacle flush to the wall. As you tighten the screw, the coil will splay out allowing you to get the proper depth on the screw but still provide support for the receptacle.


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## jbrah (May 29, 2018)

Colbyt said:


> Washers stacked and longer screws does the same thing and while frustrating may be the easier choice.


The problem with washers is they don't change the angle of the outlet to the box. Since the box is sitting at an angle, I need to a shim cut to an offsetting angle.


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## jbrah (May 29, 2018)

Thanks to everyone for the tips, especially @chandler48










You can see the box cutting on the floor. I trimmed off the face of the right side of the box to make it more or less square (dremel cutting wheel, so less square is probably more accurate). Then I took those Ideal outlet spacers, and used ~1-1/3 on side and 1 on the other side of each screw. Slicing those cleanly isn't easy because there isn't much starting material. But having more bulk to one side offset the angle the screws go in at, so the outlets are fairly close to square with the drywall and tight enough that they aren't going to move when inserting/removing plugs.

Going to be tedious to do this for several outlets, but better than cutting/patching/mudding drywall.

On a related note, I can see that the angle of the box relative to the stud changes as you drive the box in and out. The side of the box next to the stud moves more than the far side of the box for each turn of the screw. Essentially the box is flexing as you adjust it in/out. What a pain. Never using these again.


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## Oldmaster (Jan 14, 2020)

jbrah said:


> Thanks to everyone for the tips, especially @chandler48
> 
> 
> 
> ...


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