New Extension Ring Main

[smithy50]

Hi,

I'm considering doing the first fix of the electrics on a new extension; and have a couple of questions.

The extension will be lined by dot and dabbed plaster board. Will 25mm metal back boxes be the best size for the ring main sockets.

The sockets will all be fed up from below the floor boards. Does the cable need to be protected by a metal capping, or will pvc capping or conduit suffice.

Any comments/advice would be appreciated.

Thanks

 

[flameport]

25mm will do, but 35mm is a better choice as they will allow flat plate sockets to be fitted in the future when someone decides that they must be fitted now and they are the only possible option in the world and to not fit them would mean the end of civilisation as we know it.

Does the cable need to be protected by a metal capping, or will pvc capping or conduit suffice.

Protection is not required. Capping, conduit and similar is entirely optional and even when used protects nothing.

 

[securespark]

35mm is a better choice as they will allow flat plate sockets to be fitted in the future when someone decides that they must be fitted now and they are the only possible option in the world and to not fit them would mean the end of civilisation as we know it.

It's amazing how many customers like that there are.
I had a lady ring me on Christmas Eve to fit out the whole house with replacement light fittings, including some recessed ones "in time for Christmas" and was annoyed and indignant when told it would not be possible.

Protection is not required. Capping, conduit and similar is entirely optional and even when used protects nothing.

One could argue it does protect the cable from high-speed Ninja plasterers.

 

[smithy50]

Thanks for the responses - much appreciated.

I read somewhere that cables not buried more than 50mm (I think it was 50mm) had to be protected. Hence the reason for asking.

 

[EFLImpudence]

Yes, they do.

Either by RCDs, earthed covering or actual steel plate/conduit.

Capping does not count.

 

[smithy50]

That makes sense.

There will be a new split load consumer unit with both loads RCD protected and all circuits MCB protected.

So, I guess the article that I read was for non-RCD protected wiring.

 

[ban-all-sheds]

I'm considering doing the first fix of the electrics on a new extension

When you applied for Building Regulations approval, what did you say, or allow them to assume by default, would be the way that you would ensure compliance with Part P?

If you told them one thing, and then don't do that but do something else then there is a very real chance that they will refuse you a completion certificate.