Additional sockets on stud wall.

[dedwards96]

I will soon be adding some (2 or 3) additional sockets to an existing timber stud and plasterboard partition wall, and had some questions about mounting the back boxes:

• Can a metal back box be “side-mounted” to a timber stud? Ie, drill holes through the side wall of the back box instead of using the pre-drilled holes in the rear wall?
• Would this provide sufficient for a double back box?
• Are there any regulations around how back boxes are mounted?
• Is it okay to leave the pre-drilled holes in the rear unused?

The existing sockets on this wall are secured to horizontal noggings which span the gap between timber studs, but these were obviously strategically placed when the wall was constructed, and there are no such beams placed behind where the new sockets will go. I know you can get plastic back boxes specifically for hollow/plasterboard walls which is an alternative option, but my preference is for metal back boxes if possible.

As for the wiring, it’s a 2.5mm ring main with 20A MCB. I plan to either add a 13A fused spur or possibly extend the ring main, I haven’t decided yet. There is insulation in between the two plasterboard surfaces which explains why the circuit has a 20A MCB rather than 32A.

My final question:

• Does the cable (which will run horizontally directly between sockets at the same height) need to be secured in any way, or can it simply be “loose” behind the plasterboard? (Obviously ensuring it is within the permitted zone defined by the sockets)

I would inspect the current installation and follow the same standard but ideally don’t want to cut more holes in the plasterboard than necessary!

Appreciate any advice, or pointers on what else I might have missed, thanks!

 

[mainline]

As long as the back box is securely mounted, then yes.
As long as the cable is supported, then I can't see a problem.
Small holes are fine.

 

[brianmoooore]

but my preference is for metal back boxes if possible.

A sentiment I share.

There used to be metal boxes with a 10mm wide flange fitted to each end, set bout 10mm back, with a 3.5mm threaded hole in the centre of the back. You cut out your hole in the plasterboard, glued a small piece of plywood to the inner face of the wall behind, manoeuvred the metal box into place, then screwed a 3.5mm screw of an appropriate length (faceplate fixing screw), just long enough to reach the plywood, which kept the box firmly in place.
MK also used to make flanges, similar to those on the boxes above, which clipped onto the front edge of the ends of your box.
These are both no longer available, as far as I know, so my current alternative is to cut out the hole in the plasterboard with one end right against a stud, then glue as long a length of 2 x 1 batten as I can get through the hole, vertically beside the other end of the hole. When the glue is set, fix the box in place with two screws into the stud and one or two into the batten, drilling holes in the metal if necessary.

 

[Taylortwocities]

MK also used to make flanges, similar to those on the boxes above, which clipped onto the front edge of the ends of your box.
These are both no longer available,

Do you mean these?
Plasterboard Flange (2 required per box) | Wylex (SB603) - https://www.tlc-direct.co.uk/Products/AP603.html

Wylex.

 

[mainline]

Do you mean these?
Plasterboard Flange (2 required per box) | Wylex (SB603) - https://www.tlc-direct.co.uk/Products/AP603.html

Wylex.

I bet you as you try and push your socket back, the box will fall out and you’ll lose the flanges down the cavity.

 

[littlespark]

Theres always the RAF way....

cut your box out dead centre on line a joist, and hack the timber away with whatever you can find.... drill it out, multitool... whatever

ok... you might weaken the structure of the wall a bit....



Whats wrong with plastic dry lining boxes? This is exactly the situation they were invernted for

 

[brianmoooore]

Do you mean these?
Plasterboard Flange (2 required per box) | Wylex (SB603) - https://www.tlc-direct.co.uk/Products/AP603.html

Wylex.

That's them, but with the thickness of steel current boxes are made of, you'd need to close the clips up a bit before using, and, yes, they do occasionally fall off.
Haven't seen them for sale for years, but then, I haven't looked for them either.
I much preferred the boxes with the flanges built in, because the screw in the back enabled them to be fixed rigidly in place. I've even tack welded two of the above flanges in place on a box, along with a small nut in the middle of the back on occasions

 

[brianmoooore]

Whats wrong with plastic dry lining boxes? This is exactly the situation they were invernted for

An example of the long term race to the bottom of quality of work in our industry, IMHO.