What depth metal back boxes for flush wall plates

chaparral · 3 Feb 2007 at 18:36

Am looking at fitting some extra double plug sockets and a sky plate with daul coax outputs,extra telephone sockets etc and i want to mount them flush to the wall..
Plus i want to flush mount some the double plug sockets that are already there..

But am a little struck on what depth metal back boxes are best to use for this(I.E 25mm,35mm etc)

As i normal use 35mm for surface mount boxes,,but 35mm looks a very deep hole went cut out.. :eek:

as i been doing some practicing on some old blocks before attacking the walls in my house...

Tesla · 3 Feb 2007 at 18:58

From experience I would recommend fitting the back boxes designed to accommodate electric cooker sockets for the coax back boxes.

chaparral · 3 Feb 2007 at 19:02

Tesla said:
From experience I would recommend fitting the back boxes designed to accommodate electric cooker sockets for the coax back boxes.

I was thinking this (47mm).but am more then a little worried on taking this much depth out of the wall...

Tesla · 3 Feb 2007 at 20:26

What is the wall made of and where is it?

47mm are the boxes I am on about, sometimes labelled as cooker back boxes though.

Reason I use them when possible is that, simply put, you do not want any tight bends in your aerial/sat cable.

chaparral · 3 Feb 2007 at 22:21

Tesla said:
What is the wall made of and where is it?

The wall is made out of concrete..it not any of the outer walls...it a wall that goes through the middle of the house..

I don't know what thickness concrete blocks are used in this wall...

pinkaardvark · 3 Feb 2007 at 23:50

Can you not just use normal boxes with flat plate fronts. That's how I did my house all in alloy.

chaparral · 4 Feb 2007 at 00:05

pinkaardvark said:
Can you not just use normal boxes with flat plate fronts. That's how I did my house all in alloy.

Am kind of turning to doing it all with normal boxes...

In another thread i made on avforums..someone said that 6ft of the plaster came off the other side of the wall went he did his... :eek:

so be carefull when punching out the recess for the socket. I say this because I recessed two double gang sockets in my kitchen once and went a bit too heavy with the hammer and chisel, and managed to knock off a 6 ft wide lump of plaster in the living room! D'oh.
As a brick/block is normally only 100mm thick and the box you appear to be about to use is 35mm, be carefull as it won't leave you with a lot behind it

Tesla · 4 Feb 2007 at 00:10

chaparral said:
Am kind of turning to doing it all with normal boxes...

In another thread i made on avforums..someone said that 6ft of the plaster came off the other side of the wall went he did his...

Yep, that is always a risk.

I wouldn't recommend using the 47mm boxes on an internal wall to be honest. You do realise how much signal you lose going through a wall plate? I would rather not have a plate and just a very neat cable exit. Perhaps even a brush plate with all the cables coming out.

chaparral · 4 Feb 2007 at 00:14

Tesla said:
Yep, that is always a risk.

I wouldn't recommend using the 47mm boxes on an internal wall to be honest. You do realise how much signal you lose going through a wall plate? I would rather not have a plate and just a very neat cable exit. Perhaps even a brush plate with all the cables coming out.

My wall plate is meant to be a 1.5db loss..

Whatever i end up doing..i leave enough sky cable spare under the floor boards for if i want change back to having the sky cable going striaght to the skybox....

It's this sky plate am going be trying.

unknowndomain · 4 Feb 2007 at 11:47

I duno if this is relivent but isnt it against the law to do any kind of electrical installation without being properly certified? I mean like your not allowed to change a plug any more or any thing of that sort?

Tesla · 4 Feb 2007 at 11:49

unknowndomain said:
I duno if this is relivent but isnt it against the law to do any kind of electrical installation without being properly certified? I mean like your not allowed to change a plug any more or any thing of that sort?

No.

ramdor · 4 Feb 2007 at 13:00

You are allowed to run spur sockets, fit replacements sockets, new lights, replacement lights.

You are NOT allowed to run new rings.

Not allowed to add sockets or lights in to kitchens, bathrooms and outdoors.

You can do all of the above, if you have an electrican that will come a check each cable as they go in. He would do things such as record earth continuety, insulation testing and ensuring that rings are actually rings. You can even DIY it for the building regs as long as the electrican that comes to visit does all the testing etc and signs off the work as tested and up to spec. You as the DIY'er would sign the designer and installation sections of the forms.

Richie.

AS_Platinum · 4 Feb 2007 at 22:22

35mm is plently for what you want, also you can hire out a box chaser, or buy one even, they retail for about £20-40. If you do use a box chaser, ignore the instructions with regards to the cutting and make sure you put the drill on rotary hammer instead of just rotary otherwise you will be there all week waiting for the damm thing to cut the brick.