Just to confirm what I suspect, but this configuration can only mean that a spur is taken from this socket?

House built in 2015 by a large well known nationwide developer

If so it means the electrician we subsequently got in to add an extra socket, put a spur on a spur…. there’s a cable in the loft they (wrongly?) assumed was the ring main and added a spur to it using a junction box.

The spur being there could be explained by the original house developer adding an extra socket to what was planned. I remember the site manager pointing it out saying something like “we added you an extra socket so you can put the bed on either wall”. This would have likely been done at a later stage of construction, as they had to move the ensuite wall as when built to plan it was just too small.

The spur being on a spur should be ok for now as the originally spurred socket is behind a wardrobe and can’t be used. So only the new socket is used currently. But will get a different electrician to sort it at some point if needed.

Looks like 3 cables – so would think that the socket is on a ring – the 2 darker cables, and the lighter coloured cable feeds off to a spur.

Yes, I see the difference in the wires now. If they had been done all at once then they’d likely all be the same colour.

It really only occurred to me as I thought why is the ring main in the loft?

What Dirk said. If you’re only plugging in a bedside light or a phone charger and not a five bar electric heater you should be fine with the spur.

The original socket on the spur can’t be accessed. The wardrobe it’s behind is bolted to the wall.

What’s a bit odd is the socket on the ring main and the original socket on the spur are on opposite walls. The developer’s electrician could have taken the spur from the ring main socket on the same wall, a double bed width away, but didn’t.

Photo is the socket behind the wardrobe? Looks like wires head to the floor, so at least part of the ring and “original” spur may run under the floor?

Ring could be through the floor or through the ceiling/attic so doesn’t instantly scream spur off spur to me but IANAE.

If the wardrobe wasn’t there would be easy enough to isolate, remove the “original” spur, re energise and see if newer spur is still live?

Assume the newer spur isolates off the same switch in the consumer unit?

I think the photo is the main ring that the housebuilder used to create the first spur to the socket behind the wardrobe. OP suspects that this first spur has been intercepted in the loft to add another spur.

Not a sparky but perhaps the solution would be to fuse the spur to safeguard against overloading (don’t know if that’s within the regs though)

Do you know it’s a ring or just assuming it is because it’s a socket circuit? Your installation certificate will have the info about the circuit on it. Easiest fix if it is a 32a ring is to downrate the fuse to 20a instead of messing with wiring. I personally haven’t wired a ring in about 15 years as they are completely unnecessary and you run into problems like this

TBH, you really have nothing to worry about. The cable for the ring final circuit (ring mains are high voltage distribution) will be 2.5mm t+e. As it is a ring,so has 2 2.5mm conductors, it is rated for use on a 32 amp CB. (37ish actual rating). A single 2.5mm cable is rated at 26/27 amps, but, as it’s goong through insulation, that drops to around 19/20 amps.
Think about it, what 2 items in your house will use more than 20 amps for more than 30 minutes?
I’d say none of them. Your kettle isnt going to be used in the attic or bedroom, so in reality, the most you are ever going to use on that spur from the ring final circuit is when the hoover is plugged in and uses 8 amps or so for 5 minutes.
It’s all down to engineering and calculations. The Electrical Regs give a guide as to what is adequate and safe, you can make an informed decision to disregard their guidance by working out what you are doing, and concluding that there will never be a 20 amp load on that cable for a sustained time. (all cables are rated for short term overload, as they take time to warm up gradually to their maximum working temperature of 70 degrees C)
Stop worrying.

It’s all assumption, but if that’s a first floor bedroom then the ring appears to run under the bedroom floor. In which case, why did a cable end up in the loft for electrician #2 to find?
As dmorts says, it’s “a bit odd” but may have been a reasonable choice for the spur at the time

The inaccessible socket may not be compliant with regs because it’s inaccessible.
Check that there are three earth conductors inside the sleeving – photo (no reason why there wouldn’t be)

Do you have a minor works certificate from electrician #2?

X-post while making tea 🙂

I realised there is a still a chance the wire in the loft is a ring main. All I know is there is a spur off that socket, it could be that another socket in the room is on the spur, and not actually the one behind the wardrobe. I will check the wiring in the others. There are 4 in total, only one is behind the wardrobe. If I find one of the accesible sockets is the spur then everything would be ok.

The inaccessible socket may not be compliant with regs because it’s inaccessible.

Wasn’t aware of that. All of this is only a really a concern should we sell the house.

Check that there are three earth conductors inside the sleeving – photo (no reason why there wouldn’t be)

I had the same thought. I’ll check.

Do you have a minor works certificate from electrician #2?

I’m sure we did

may not be compliant with regs

Ah yes, the over used phrase of all house surveys and any electrician who is looking at a previous electricians existing handiwork… 😉

Wasn’t aware of that. All of this is only a really a concern should we sell the house

It’s a requirement for inspection and maintenance reasons, unless the terminals are maintenance-free. Anybody should ideally be able to visually check for damage, sparks flying and that sort of thing 🙂

I’m sure we did

That should reassure you

Checked the next socket along on the same wall as the socket with a spur taken off. The next socket along has two L and N wires so that isn’t where the spur goes. So I’m now sure the wire in the loft is a spur and I have a spur on a spur, albeit with the final socket on the spur inaccessible.

final socket on the spur inaccessible

It isnt inaccessible, it is behind a wardrobe. Inaccessible is when it is plastered into a wall with no access at all, or if it is totally boxed in. Being behind a moveable (ok, screwed to the wall, but still moveable) would not cause any concern to any electrician doing an inspection. The worst case scenario is a C3 code, which is ‘improvement recommended’. I’ve done hundreds of inspections,and around 50% of them have sockets or switches hidden behind furniture etc. The only note I put is something like “socket in living room near door not accessible due to fish tank in the way”.

Being behind a moveable (ok, screwed to the wall, but still moveable) would not cause any concern to any electrician doing an inspection.

Useful to know how things have moved on, I’m a couple of sets of regs out of date now but IIRC the IET wouldn’t commit then and even included fitted carpets as a matter for debate
This led to an amendment to allow maintenance-free terminals and a best practice note to avoid using them in favour of accessibility 🙂