More Questions - Electrical sockets

[Stephen Gilkes]

Hi all

When fitting an electrical socket, should the edge of the mounting box be flush with the outer surface of the wall?

So for example, if your plasterboard is 10mm thick fixed onto 25mm batten, should you use 35mm mounting boxes.

Or can you get away with using 25mm mounting boxes?

I would like to fit all my mounting boxes before I fix the plasterboard. I was hoping that once the plasterboard was fitted I could just drill and open up the hole over the mounting box. However, if the mounting box was 35 mm I wouldn't be able to fix the plasterboard on (unless I had created the hole in the plasterboard first - which I don't want to do)

Thanks for your time.

[Mal]

That would just be a pain - you would have to cut your plasterboard exactly to fit. It would be much easier to fit the sockets afterwards.

There are special dry lining boxes available for use with plasterboard. They have plastic "ears" which grip the back of the wall when you fix the faceplate on. One word of warning - don't buy them from Homebase - they charge at least 4 times as much as B&Q (and a lot of builders merchants are just as bad).

Mal

[Kalico]

It is not necessary for the edge of the metal box to be perfectly flush with the surface of the plasterboard/plaster. That said, I would not advise a massive gap.

What you say about creating the hole in the plasterboard first is what I have seen most plasterers do, so I am not sure why you don't want to do it first. Usually, when I am wiring to a brick wall, prior to plastering (which is so much easier than hacking out!) I just run the cables up, down or along to the 25mm box (this is the most common size btw) which I have mounted easily straight onto the brick. The rest of the work is then done by the plasterer who cuts the holes and skims. The holes are usually a little larger than the box to allow for movement mounting the board, but these gaps get filled when skimming.

Any plaster that has run into the box can most easily be cut out with a knife, preferably before the plaster is fully set. Otherwise, break it off after scoring when it has hardened fully.

Remember to use grommets where the cable passes into the metal box.

The problem I see with your method of drilling to *open up the hole* after the board has been mounted is that you could well drill through into the cable itself.

Hope that helps. Rob

[Stephen Gilkes]

Thanks Guys!

[Andy Hall]

Ideally, yes.

You could, but you might need to buy longer fixing bolts for the sockets.

Another approach is to buy plasterboard boxes. For these, you cut holes in the plasterboard after fixing. The boxes then push into place and there are fixing clips captive in the box which then push into position behind the board The fitting bolts then secure everything..

.andy

To email, substitute .nospam with .gl

[usenet]

The OP appears to be using plasterboard on battens on a solid wall.

The normal way to put sockets in plasterboard is to use dry-lining boxes, I think these would eb the best way for the OP's situation too rather than using metal boxes fixed on the wall behind the plasterboard.

[Christian McArdle]

OTOH, metal boxes do have some advantages.

1. Much firmer, good for knocking in stiff plugs.
2. You don't get that white lip, which can be obvious is differently shaped to the socket, or the socket isn't white.

Christian.

[chris French]

In message , Christian McArdle writes

Indeed, which is why I prefer to use them if possible in most situations.

[chris French]

In message , Kalico writes

I've put a couple of metal boxes in plasterboard walls recently. I tried both the cut the hole first, and the cut it afterwards technique. I think the latter was probably quicker. Though both work fine.

When cutting the hole afterwards, I mounted the box flush with the rear side of the PB. . When boarded and skimmed I use a small drywall saw to cut round the inside of the box. As long as you take care it's easy enough not to knacker the cable.

>

[Lurch]

It's usually cheap sockets, not dodgy plugs!

The way around this is fit the boxes before plastering. One thing to bear in mind is dry lining boxes are 35mm, you will probably find that some will not fit back to the board properly because of protuding bits of wall. The usual use for dry lining boxes is stud walls, for dry lined walls metal boxes attached to the brickwork is the more common method. ..

SJW A.C.S. Ltd.

[Kalico]

You can use dry lining boxes but I only use them if wiring a new socket into an existing plasterboard wall.

If I was doing what the original poster said, I would use metal, fixed to the wall, maybe even on a small wooden pattress to push forward a bit, and then cut a hole in the plasterboard afterwards.

HTH Rob