Cutting through noggin to replace flush boxes

Richard Green · Mar 15, 2013

Hi,

I've recently moved into a 1970s built house with stud partition dividing walls. The electrical fixtures and fittings are quite dated, so I've decided to replace all the sockets and switches and also to convert single sockets into doubles whilst I'm doing it.

Unfortunately when I came to install the replacement fittings I realised that the current back boxes (16mm - I think) are all too shallow for the newer switches. I'd like to replace the back boxes with new deeper boxes. However I'm not sure how to proceed; the current back boxes are the standard old-style steel boxes, which have been screwed to a noggin installed at light switch and socket height behind the wall.

So my question is this: can I just cut through this horizontal length of wood and install standard dry lining boxes into the wall in the place of existing boxes? or is this piece of wood also supporting the dry wall? If it is supporting the wall, how can I proceed?

If I can go ahead and cut through the wood, I was planning to use a Bosch (or similar) multi-tool to cut through them then to install 47mm boxes like this (or 35mm if there isn't enough room): 2 Gang 47mm Fire & Acoustic Metal Dry Lining Box does this all sound ok?

Any suggestions or advice would be greatly appreciated.

telectrix · Mar 15, 2013

25mm boxes will usually do for most accessories. no problem cutting the noggins deeper. they were probably fitted just to screw the back boxes to anyway , and have no structural functin.

KAS1 · Mar 15, 2013

Sounds all good

Rampantchilli · Mar 15, 2013

I'd advise using 35mm boxes, and 2 cut out the wood I'd use a large flat wood bit and a reasonable wood chisel, between them you'll clear out all surplus wood with the minimum of disruption and effort, whilst your idea of cutting out the 'nogging' sounds good, in practice you'd struggle to get the depth, plus if there are nails in them you will almost certainly cause more unwanted damage.
by leaving in the nogging you can use the metal box and use the wood for a good fixing