Using junction boxes to extend a ring circuit

[bobbyp]

I need to add 3 sockets into a room that currently only has one spur. TO do this I'd like to extend the ring from the room next door.

The easiest way to do this appears to be to break the ring and install junction boxes to join in the new section. Looking through this site it mentions that this method doesn;t appear in the new wiring regs. Is there a reason its gone?

Is the reason that junction boxes must be accessible for inspection? If so does under a short, easily lifted floorboard in a doorway count? There will never be anything on the board so it should be accessible.

Advice appreciated before I have to try and route the cables all the way back to a previous socket.

 

[davelx]

You don't know that a future owner of the property won't cover that board with carpet, tiles, etc.

Better to run new cable from the existing socket, or if that is not possible, use crimped joints covered with heat shrink, which is classed as permanent.

Use proper ratchet crimpers - available from electrical wholesalers, RS, etc.

 

[mapj1]

Or add a dummy socket at the point where the junction box would otherwise have been, or even a back box and flush blanking plate. The same trick often used to make 'pukka' routes that are not the lines of least surprise, by generating a new permitted zone around the new back box. (though the draft of the next eduition suggests an RCd will soon become an alternative to following the permitted zones.)

 

[JohnD]

If you have a socket in the next room that is on the ring (let's hope it's on the adjoining wall) a reasonable way to do it is to take out the existing socket, and fit a dual box with two single sockets.

One leg of the ring to one socket, the other leg to the other.

Now picture that you have two sockets, each connected to one leg (forget for the moment how close they happen to be). You can take the ring away from one of the sockets, leading it on an interesting journey, with plenty of outlets, and returning to the other socket. You now have an enlarged ring.

BTW if you are planning to install plenty of sockets in a room (one every 2metres or closer) there is a lot to be said for chasing horizontally around the room (no need to burrow under the floor except at doorways). This method is very economical in labour and materials. It is also very suitable for kitchens, where the row of outlets can be 150mm above worktop height.

 

[bobbyp]

Thanks for the advice.

I had a quick peer about last night and I reckon its not going to be too bad to go back to two sockets on the ring and do it properly, saves having to chase dodgy crimp connections in a few years time.

I like the idea about chasing round the walls but I've got a few data cables to run as well so the floorboards are up anyway. Worth bearing in mind for other rooms though.

Bob.