Electrical Question

Holes around plug sockets and switches.

Boxes set too deep within plaster. 2 questions really

How many different types of box depth can you get?

What is the cheapest way of fixing this problem? (as I'm guessing even if I can get a deeper box it will be expensive to fix)

2 Answers

Best Answer

Hi Glenone, there are 4 diffent sizes of flush galvanised steel boxes that you can get.

For sockets the most common size used is 25mm although 35mm is used if old/existing plaster is thick.

The 47mm deep boxes are usually for cooker panles and shaver points, that need a deep box, where as light switches tend to be 16mm or 25mm deep.

just because the flush box has been set too deep in the wall, it should not be a problem. You can use longer 3.5mm accessory screws or extensions (called stud post screws) - see link below


You can also get extension rings, but these ar e abit harder to fit as you'll need to chase a bit of the plaster out, so long screws is the better option.

link to extesnsion box;


Hope this helps, please click on "like" if it does.

Answered 24th Feb 2012

Electrical Safety Services

Member since 17 Oct 2011

Boxes depths are -16mm,25 mm,35mm and 47 mm.
Even if the boxes are too deep,switches and sockets still can be screwed to the boxes,using long 3.5 mm screws or stud extensions.
They are with maximum length of 100 mm,which should be ok for your boxes.
If they too long( screws) cut them to the desired length,careful not to damage their tread.
another way of fixint that is to use skeleton boxes-they look like a normal box,just without the back wall.
Hope this helps

Answered 24th Feb 2012

Elman Ltd

Member since 6 Nov 2010

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