Spur socket - tee into existing wiring

[scousespark]

it's probably against the regulations.
But what I would do is.

1) get a traditional junction box.
2) using a sharp knife, cut down the middle of the cable where the earth wire is, for the length of the j/box
Remove the outer grey sheaf
3) take the grub screws out the junction box and put them safe somewhere!
4) bend the wires so that the wires pass thru the terminals and junction entry.
5) with the knife, remove a small amount of the red and black insulation where they pass the terminals. (without cutting wires)
6) spur in your new cable to the terminals.

The advantage of this method is that you haven't broken the ring. You will never have a poor joint in the ring because of this junction.
The only thing that could stop working is the newly fitted socket.

You can't fit earth sleeving to the ring, but the wires aren't going anywhere.

I'm sure this will be a more reliable junction in 20 years time than some bloody MF junction

The ring does stay in tact, but surely there is still a joint connecting the spur cable.

 

[AndyPRK]

The ring stays good so you never need to hunt for a high resistance connection in a hidden jb which should please a lot.

The only failure mode is one spur socket having an issue.
That should be fairly obvious as to where and why.

 

[Keithmac]

Avoid junction boxes, add the new socket onto the ring and not as a spur.
View attachment 162612

Best bet by far if you can run the new cable reasonably easily..

 

[AndyPRK]

Thanks all. Good to know this is considered acceptable practise as it will be much easier than taking a wire from one of the other sockets.