Depth to mount Knockout back boxes

[Jaeger_S2k]

Greetings Everyone,
Great forum and giving me more and more confidence in getting into my fairly large project. More about that later.
I'm a brought up plumber, Father was a Fireman and a Plumber Gas Fitter, I was his mucker for many years so learnt the proper way.

First off – Build new stud wall that will extend the lounge by about 1mtr, using existing doors and casings and surrounds. Then knock down existing and repair holes, knock down under stairs wall and repair then finishing plaster all?

Currently have built the stud wall (my first stud wall) and it's looking very much like a stud wall! (Thank the Gods!)

Have dry lined one side as I'm going for Fermacell on the other which will be hung with kitchen units.

I want to get the wiring in place for the sockets both sides, I would like to put back panels in for the Knockout Boxes but not sure of the depth? Can someone give me a guide for this?

A size I will never forget is the hole in a Stud Wall for the door casing is 810mm, somehow I managed to make it 800mm so some inventive planning 5milli off each casing and it's got the original door hanging in it today, snugger fit than it was in the original wall.

Ultimately there’s a ground floor extension with garage being built, so foundations and lots of finishing work for me. Having the bricks down by someone more proficient than me, I’ll be doing all the finishing work unless it’s something I don’t understand.

[tim'll fix it]

sorry never worked with fermacell but cant you use dry lining back boxes

if you want to use steel boxes they should finish flush with the front edge of the wall (plasterboard/fermacell) whatever

[Jaeger_S2k]

Could do Tim, but the benefits of Fermacell are compelling.

Weight bearing without additional noggins, so no need to work out where and how many (Mr. Lazy) also provides a 1 hour fire wall, useful for a kitchen area. There is also a coating which when applied in 2 coats provides a plastered finish.

Not used it yet will report back on the results.

Thanks for the reply, just need to decide which size of back box and put the backings in. Dry lining boxes are not as secure and can come loose then you're fecked!

[-dj-]

just use the deep back boxes then and you can't go wrong!!

[Jaeger_S2k]

just use the deep back boxes then and you can't go wrong!!

[Hinton Heating]

If you do, you'll need some different screws, as the ones supplied with plate will be too short.

But then DJ is used to short things

[-dj-]

yes, you can buy the longer screws from b&q or screwfix etc.

and yes i'm used to short things but i have a nice looong marshaltown