> >

Installing a electrical mounting box

Cost: Difficulty:


Electricity is dangerous and can be hazardous. In doubt? Call a qualified electrician.

Installing a electrical mounting box

There are different types of mounting boxes available - plastic surface mounting boxes, inset (flush mount) metal boxes and there are also pattresses for converting single inset mounting boxes to double or treble surface mounting boxes.

Surface mounting

You will require a plastic surface mount box in order to surface mount a socket. If the mounting box is to go into a cavity wall then a shallow mounting box (25mm deep) should be to prevent knocking through to the cavity.

On Masonry Hold the surface mount box on the wall at the position you would like it and ensure that it is horizontal using a spirit level. When it is horizontal mark the fixing holes and remove the box. Next drill where you marked the fixing holes and place wall plugs in the holes.

On the mounting box decide where the cable shall enter the box and use pliers to break out the plastic entryway. Now pass the cable through the hole and align the mounting box up to the fixing hole you have drilled. Use countersunk screws to fix the mounting box to the wall. Before they have been fully tightened, use the spirit level to finally level off the mounting box.

On Plasterboard

Fixing a surface mount box to a plasterboard wall can be done in a similar way to masonry except that different wall plugs are used, i.e. those for plasterboard walls..

It is best when placing the mounting box on the plasterboard wall to align it so that the fixing screws go into the wooden frame behind the plasterboard. If you decide to do this it is important to check that it is possible to feed in the cable from behind if required.

Flush mounting

You will require an inset mounting box to flush mount a socket.

On Masonry

Place the metal mounting box against the wall at the desired location and draw round it with a pencil. Mark a path from the location of the mounting box for the cable to reach it, e.g. from the skirting. Remove the plaster from within the marked area by first scoring the pencil line you have drawn and then using a masonry chisel and hammer.

Once the brick is exposed where the mounting box is to go, some of the brick will have to be removed. To do this fit a drill with a masonry bit and mark the depth of the mounting box on the bit. Next drill into the brick in a grid pattern as shown here:





Finally use a masonry chisel and hammer to cut away the remainder of the depth required for the mounting box. Make sure the box fits and then mark and drill holes to attach the mounting box to the brick behind. Use wall plugs in the drilled holes to secure the box . Pull through the length of cable required and attach the mounting box in the hole.

Finish the job by plastering around the box and the cable channel as necessary.

On Plasterboard

Once you have decided where the socket is going to be located, draw round the mounting box on the wall ensuring that it is horizontal using a spirit level. The hole should then be cut in the plaster wall using a sharp knife. Feed the cable through the hole then choose the best hole to remove in the mounting box and knock it out.

Fit a grommet to the cable entry hole and fit two lugs to the mounting box. Then pass the cable through the grommet and slide the box into the wall so that both of the lugs are behind the wall. The box should now sit behind the wall in position. The socket can then be wired up and screwed in place. By screwing the socket in place it clamps the plasterboard between the lugs and the socket.

Need help or supplies?

Further help required?

Our forum is the perfect place to ask questions and get help. Join us, post your question/comment now!