Cutting out wall for a double socket

[Rolo]

Hi,

Alot of the sockets in my house were old and were raised boxes on the walls ie not set into the wall.

Ive got one of those things which you attach to the wall and has guides for you to drill through, then you take it off and knock out the brick, plaster, all of them have been done before I have plaster work and decoration done. However now I need to put a new socket in in a room thats already been plastered and decorated.

Anyone got any suggestions /advice how I can as clean as possible cut the socket recess into the wall doing minimum damage or is the only way to do it slowly and carefully ?

Cheers

 

[luminaire]

Have a look here

 

[rjb]

Or if your wallet doesn't squeak when it opens then try this. There are also versions for double plugs too. Loads of companies do them, search for ''electrical box sinkers'

Link

 

[Space cat]

That link that luminaire provided is a good start but it misses out a lot of detail. This statement

"Now chisel the masonry away using a bolster chisel and hammer to the correct depth. In old plaster or if the brickwork is poor this can be very difficult and can lead to large amounts of plaster falling off!"

glosses over the hardest part of the job.

I never use a bolster directly on the plaster surface. It's sure to send bits flying in all directions and leave a ragged edge. Use a craft knife and straight edge to cut through the plaster surface first. After that you can use your bolster, carefully, to break up the square in the middle. Continue scoring with the knife and chipping with the bolster down through the plaster until you reach the brick.

The next bit is where the hard work begins. Don't just start bashing the brick head on. That's a good way to knock the brick backwards into the cavity. (I learnt this the hard way. I'm not a freemason but I'm quite cheap!) Start by drilling a hole in each corner then put a few more around the edges and in the middle. To get the bulk of the brick out without dislodging the whole brick you have to angle your bolster. It's difficult at first because the thing just wants to slide but it gets easier once you've broken through the surface. Work across the surface towards each edge. Take your time.

Hint: On really hard surfaced bricks I use a plugging chisel to cut grooves linking the starter holes.

 

[Chri5]

I'll score the plaster, run maybe 30 holes around the shape with a sds 4-6mm drill bit with tape marked at 30mm depth (for a 25mm box) and then use a flat bladed 40mm sds chisel.

Take about 10 minutes, if the chisel bade is kept sharp with a stone. The blade dulls after 10-12 double box chops.

For a double box I'd drill something like this, the corner points being the most important of the drill markers

0--0--0--0--0--0--0--0
0-----------0----------0
0-----------0----------0
0-----------0----------0
0--0--0--0--0--0--0--0

I would add that unless your taking a cable in via the back of a wall or a brilliantly drilled tunnel from somewhere within 500mm, there's going to be chase damage not matter what

 

[Lectrician]

'stitch drill' with a 5mm masonary bit around the marked out outline of the box, and then infill the marked area with loads of 5mm or larger holes.

It is always going to work better on houses build since around the late 60's.

Internal stud walls, obviously just use a padsaw, and also for dry-lined block walls - use a padsaw and/or stanley, and then gently knock the blockwork away, with the help of a drill if required.

Older buildings with stone or brick as opposite to block work can result in plenty of plaster drop!

 

[Sureitsoff?]

i agree with Lectrician as to the stitch drilling, take out as much as possible with the drill and if you can get a helper ie her indoors (if available) to hold the constantly running hoover (other makes are available!) below the point you are drilling, that will minimize the dust that this sort of operation will cause