I intend to wire in some new sockets for a friend in his conservatory. They
are going onto some breeze block which will then be plastered. How thick
will the plaster be. Do I need to cut out some of the block to accomodate
the thickness of the back box and the wires or will the plaster be at a
sufficient depth to hide the lot.

TIA

Do I need to cut out some of the block to accomodate the thickness of
the back box and the wires or will the plaster be at a sufficient
depth to hide the lot.

Light switch back boxes can often be mounted directly, whilst a socket back
box needs some block chopped out. It depends on the plasterer.

Christian.

In article ,
Christian McArdle wrote:
Light switch back boxes can often be mounted directly, whilst a socket
back box needs some block chopped out. It depends on the plasterer.

Trouble with plaster depth switch boxes is they restrict the choice of
switch or dimmer. If you're doing a re-wire it makes sense to fit deep
ones.

--
*Also too, never, ever use repetitive redundancies *

Dave Plowman London SW 12
RIP Acorn

In message , Christian
McArdle writes
Do I need to cut out some of the block to accomodate the thickness of
the back box and the wires or will the plaster be at a sufficient
depth to hide the lot.

Light switch back boxes can often be mounted directly, whilst a socket back
box needs some block chopped out. It depends on the plasterer.

I usually work on a plaster depth of about 15 mm max. (which just about
fits a light switch box - 16 mm I think) others therefor need to be
sunk a bit. It's better to have then too deep rather than to shallow
--
Chris French, Leeds

"Michael McNeil" wrote in message
om...
"John Woodhall" wrote in message
...
I intend to wire in some new sockets for a friend in his conservatory.
They
are going onto some breeze block which will then be plastered. How thick
will the plaster be. Do I need to cut out some of the block to
accomodate
the thickness of the back box and the wires or will the plaster be at a
sufficient depth to hide the lot.

TIA

Chisel out the thickness of the box and a bit to allow it to sink in,
under flush. Put square of cardboard over it to hold the wires in and
to stop the plaster filling it.

You will have to render the wall first, so that will be say 1/4" to
3/8" or more thick, depending on how plumb your walls are. The plaster
will be two coats thick adding another 1/8" to a 1/4" depending on how
good you are at plastering.

Few electricians bother to chase the trunking. That should give you
some idea of the finished thickness. The screws supplied for the cover
are that length for a good reason. You can even buy longer ones, so
don't worry about laying it on too thick. Better that than too thin.

Maybe the plasterer is using dot and dab. In which case a 25mm back box need
only be sunk by about 5mm and even then you will probably need extended
screws to fit the faceplate. The screws supplied for the cover are never
deeper than the back box they are expected to fit, but as been said you can
buy longer ones.

Whatever method, if you can follow the plasterer and use a knife/blade (but
not on your cables) to clear the plaster out of the back boxes leaving a
nice squared off finish before the plaster is dry then the faceplates will
sit very nicely on the plaster. It is a nightmare trying to clear out the
dried plaster from back boxes.

Adam

In message ,
ARWadsworth writes
It is a nightmare trying to clear out the
dried plaster from back boxes.


Not sayting you should leave it to dry if you can avoid it, but I've not
found it a great problem.

I use an old screwdriver (with a hammer if necessary) to knock it out.
It doesn't stick hard to the metal and comes off easy enough.
--
Chris French, Leeds

"John Woodhall" wrote in message
...
I intend to wire in some new sockets for a friend in his conservatory.
They
are going onto some breeze block which will then be plastered. How thick
will the plaster be. Do I need to cut out some of the block to accomodate
the thickness of the back box and the wires or will the plaster be at a
sufficient depth to hide the lot.

TIA



Many thanks all. Best get the SDS out then :-).

John Woodhall wrote:

"John Woodhall" wrote...
I intend to wire in some new sockets for a friend in his
conservatory. They are going onto some breeze block which
will then be plastered.

Many thanks all. Best get the SDS out then :-).

Blimey, for breeze block?
--



__________________________________________________ ______________
Sent via the PAXemail system at paxemail.com

In message , jerrybuilt
] writes
John Woodhall wrote:

"John Woodhall" wrote...
I intend to wire in some new sockets for a friend in his
conservatory. They are going onto some breeze block which
will then be plastered.

Many thanks all. Best get the SDS out then :-).

Blimey, for breeze block?

If you've got it , flaunt it...:-)
--
Chris French, Leeds

"jerrybuilt " ] wrote in message
...
John Woodhall wrote:

"John Woodhall" wrote...
I intend to wire in some new sockets for a friend in his
conservatory. They are going onto some breeze block which
will then be plastered.

Many thanks all. Best get the SDS out then :-).

Blimey, for breeze block?
--



Perhaps your right. Dont want to demolish it do I.

But then again, gotta get your moneys worth. ;-)