Electrical sockets in shallow partition wall

[Chris Emerson]

I'm trying to put sockets into a partition wall, but there's not much space. The wall consists of two sheets of plasterboard, each 20mm thick, with about a 10mm gap between, giving 30mm depth for the box.

So 35mm drywall boxes don't fit, and I haven't found any shallower ones anywhere. A 25mm one would be just the thing, but do they exist?

A metal 25mm deep box fits, but I'm not sure how to fix them. Are there any good ways to screw/nail sideways into the surrounding plasterboard without it splitting/crumbling?

For the original sockets in the (1960s) house which aren't in the solid walls seem, they seem to have made a small wooden frame to screw the metal box into. That's possible, although quite labour-intensive. I'd prefer to do that than use surface-mounted boxes, which is what has been used here before.

Any ideas/advice welcome!

Thanks,

Chris

[Lurch]

On 16 Apr 2004 08:02:42 +0100 (BST), in uk.d-i-y Chris Emerson strung together this:

You could 'glue' the box in, with some plaster or gripfill, or anything that sticks. If you try your local electrical wholesaler you can get dry lining adaptors for metal boxes, Appleby is one manufacturer for a start.

[Sean Delere]

I presume the back of the partition wall is visible, if not you could screw the metal boxes in as normal with plasterboard fixings.

I suspect your best way will be to cut the hole for the box in the plasterboard then glue it in position using something like no more nails or gripfill. You could strengthen it by screwing a couple of wings to the back box that slide out into the 10mm gap.

Sean

[Stephen Dawson]

I have and would use expanding foam for this job the stuff is excellent

Steve Dawson

[Stuart]

Why not just cut away the furthes away plasterboard as well -would that not give sufficient depth for a drywall box . ?? Stuart

[Chris Emerson]

In one case the other side would be behind the bath, but the others are the wall in another room so I can't really do that.

Thanks. Glue and extra wings sounds like it may be the way to go.

Chris

[Chris Emerson]

It would, but there'd be a big hole on the other side of the wall. :-)

Unless there's a plausible way to cut only 5mm into the other bit of plasterboard...

Cheers,

Chris

[Dave Plowman]

Best way is to fix two wood battens, roughly 1 x 1 in. either side (or top and bottom) on the back of the plasterboard, flush with the edges of the hole. Make them about 2 inches longer than the slot (one inch either end). If you have to make good the decorations anyway, simply screw them in place using brass screws and fill the heads flush (ordinary ones will corrode in time and lift the filler), or glue in place with 'no nails' etc. Then screw the metal box to these. You might have to drill holes in the metal box to line up with the wood, and if they're glued in place drill pilot holes for the screws too to avoid dislodging it.

This will give a fixing as strong as the plasterboard, and neater than most dry lining types.

I use this method for fixing to a plasterboard wall regardless of clearance, having seen too many dry lined boxes fall out...

Takes longer, of course, but we're not pros working by the hour.

[Chris Emerson]

If I'm understanding right you mean between the two plasterboard layers, but there's only 10mm of space between them here. Could maybe make the hole wider and screw into the battens from the other side of the wall (if accessible). Or am I confused?

That all sounds useful, thanks.

Why did they fall out - hole slightly too big, not tightened enough, or just not a good way of holding the wall?

Thanks,

Chris

[Dave Plowman]

10mm battens would still be enough to get a good fixing to - although you'll need to be more accurate. It's a strange construction of wall - what holds the plasterboard sheets apart? Or are they those double types separated by cardboard?

Usually the hole cut too big, or the edges damaged.

[N. Thornton]

The simplest way to fix the sockets would be to use 2 toggles, or other similar cavity wall fixings, and the socket screws into them directly.

You should also enclose the wiring in a suitable backbox: to do that I might take a dryline box and cut the front half off it, so it covers the wiring in the wall, but doesnt do anything fixing wise.

Regards, NT

[Sean Delere]

Wouldn't the foam approach cause the socket to pull out slightly when pulling out the plug?

I have only used the stuff once and it did have a bit of give rather than being a solid fixing.

Sean

[Chris Emerson]

Don't know I'm afraid! What I can see where I've cut the hole near the bottom, is that one sheet is resting on a batten of some sort while the other seems to go further down. They're both resting on top of the floorboards upstairs.

Cheers,

Chris