Remove old back box?

[securespark]

This could be 'egg box' type wall, or the similar type where there is a central board with a board either side - like a sandwich.

Paramount is its name. I have shed-loads of it Chez Secure. But I've never had an issue with it. I have fitted dry wall back boxes with no issues and if you need to "channel" in a cable, you just ram a length of oval up (or down or across!), pushing the cardboard pieces out of the way. See this thread:

https://www.diynot.com/diy/threads/whats-this-stuff-behind-my-plasterboard-wall.233735/

 

[Croftie]

Ok it is block and not plasterboard like I thought. So I'll need a metal back box and what plaster to "muck it in"? Any other tools I'll need?

TY.

 

[chivers67]

If it's block work you should be able to use a couple of rawl plugs if it's deep enough. Otherwise a small amount of bonding is good.

 

[333rocky333]

A deeper back box will have screw holes in the side, which may be preferred if you think the walls thin.
Too be honest plaster is usually enough to hold a switch box
Unless you have a good eye, use a spirit level and if the box only has one adjustable lug, then try to fit with that lug usable.

 

[Croftie]

Good advise there thanks. What plaster/filler should I use to patch up if needed or to hold the box in place if I can't screw it in, something like this?

 

[Iggifer]

That would be fine for filling around the box, I wouldn't use it to fix the new box in though.

http://www.diy.com/departments/thistle-one-coat-plaster-125kg/147437_BQ.prd

I would recommend browning plaster, but it's harder to get a good finish for any touch up with browning

 

[Croftie]

The browning is a lot cheaper than that one coat so I could get some browning to fix the box and a tube of that stuff for touch up.

What about hardwall, just watched the chap in this video showing how to mix and apply it, would that be better than browning for this use or are they about the same?

 

[EFLImpudence]

Anything will do; it doesn't matter - but preferably something that sets quickly.

 

[Croftie]

Alright, think I'm confident enough to get on with it now. Thanks all for your help.