Kalico wrote:
"Stephen Gilkes" wrote in message
...
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.

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.

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.

--
Chris Green