Old House - horizontal wiring behind skirting

DJSheridan · Feb 16, 2020

Hello all,
Just some advice...
I am fitting insulating boards on an external wall in a bedroom (50mm thick with plasterboard) as the end terrace wall is solid brick with no cavity...

I am wanting to spur off an existing single socket in a bedroom (two cables going to it) to an additional double socket along the same wall at the other end.
Problem is I have taken up the floor boards to check where the wiring is going and found no cables near this single socket under the boards...
In fact the only cables I did find were at the other end where i want to place the double additional socket. These both come up from below (I suspect from a double socket in lounge) but instead of running along through joists they go up behind the skirting board and then it appears they run along the top just behind the skirting board. This is bad as potentially not safe - although it is an old house from 1910 era.

The existing single has two cables - one going one way and the other going towards where I want the double addition.
So I'm thinking that the two cables are part of the ring to the downstairs lounge sockets - but really surprised how they are run.
The single is fed in and the out runs and appears to go to the lounge socket downstairs - with the return back up and along the skirting board... not sure where it goes though as not pulled the skirting off the wall yet.

So if it is a return cable would it be okay to use a Wago junction box under the floorboards and create an additional socket from this return cable from downstairs - in essence adding in another socket to the ring - and run it behind the skirting board and up to where i want it then fit the insulation boards over it?
I can just spur off from the single and place cable under the floor boards within the joist... but thinking that adding into the main would be safer?

Also is it better for me to remove this return cable and re-run it through the joists to make safe or is this me just being over the top?

Or is adding another socket to the main reportable under the building regs or just on new builds?

Don't want to do something wrong... and the additional double socket is only going to be for a laptop and the USB outlets for a phone...

SJD · Feb 16, 2020

Probably the first thing to do is test if these two cables in the existing socket are indeed part of a ring (measure end-to-end continuity) (assuming the circuit is wired as ring, on a 32A MCB).

The socket could well be a spur, with another (non-compliant) spur off it. I found an extension with a total of 6 sockets spurred of each other from a lounge socket on the ring recently. So better to be sure before you consider where to run any new cabling.

DJSheridan · Feb 17, 2020

SJD said:
Probably the first thing to do is test if these two cables in the existing socket are indeed part of a ring (measure end-to-end continuity) (assuming the circuit is wired as ring, on a 32A MCB).

The socket could well be a spur, with another (non-compliant) spur off it. I found an extension with a total of 6 sockets spurred of each other from a lounge socket on the ring recently. So better to be sure before you consider where to run any new cabling.

Hi there,
Thanks for the response.
I do think that these are mains as if spurs they would only have one cable to them? I have searched on here and online and youtube and this seems to be the case that if two cables then should be a main.
I will remove the skirting fully then see what's what - then if in a huge doubt will contact an electrician for advice.

DPG · Feb 17, 2020

Without testing its impossible to know though. 2 cables at the back box may mean the socket is on a ring, but it may also mean a spur off a spur. It may also be a radial.

davesparks · Feb 17, 2020

DJSheridan said:
Hi there,
Thanks for the response.
I do think that these are mains as if spurs they would only have one cable to them? I have searched on here and online and youtube and this seems to be the case that if two cables then should be a main.
I will remove the skirting fully then see what's what - then if in a huge doubt will contact an electrician for advice.

A correctly installed spur will have one cable, an incorrectly installed spur may have more than one cable.
Also if it was wired to an old version of tbe regulations then 2x single sockets on a spur may have been compliant at the time of installation.
You will also find that sockets with 2 cables could be on a radial circuit rather than a ring.

So the only sure way to know if it is a ring or not is to test it.