Extending ring final - any potential gotchas?

[ninemaverickbars]

Hello again, been a while.

I'm wanting to extend a ring final and I'm at the 1st fix stage as part of some building work to open up our ground floor. Following demolition, a 2 gang socket is redundant in place, so my plan is to extend the ring and add 2 further 2 gang sockets. To join into the ring I'm planning to use a pair of Hager 32a maintenance free boxes which will be fixed to a plate across a joist.

Other than calculations for the loading due to the increase in sockets on the ring, is there anything else I need to think about? One of the sockets will accommodate a washer dryer, but the others will be used for light loads only (at least by us).

However, as overloading can be a concern when adding sockets, I'd also be interested to know how professionals usually document the work, for the benefit of future occupiers. Both location of the cables and also which circuit they pertain to. We are taking detailed photographs, but it would be nice to have something that makes sense for anyone who happens to read it, for safety's sake and also for future maintenance.

Floor area is less than 100m2.

I do not believe any of the work I'm undertaking is notifable and we're not doing anything with the distribution board. Please correct me if I'm wrong.

Many thanks, as always.

 

[James]

modifications to an existing circuit are not normally notifiable.
however they should still be tested and documented to be safe.

extending a ring in a domestic setting is generally considered not to increase the expected load on the circuit by a meaningful amount.
lets face it, most sockets are now days used for phone chargers, led lamps and a couple of tv type devices.

if at all possible i would avoid using any sort of junction that is hidden out of reasonable access, even though it may be ok with the reg's.

trace the cable back to the last junction and remove the old, replace with new.
hidden joints could cost you 10 to 100 times the cost of doing it right in the first place, when later you are trying to find/fix a fault.

also, be aware that the best DiY work is often just a little bit shy of a professional when they are having a bad day, I am not questioning your ability's but there is an art to this electric stuff that takes some time to hone.

further to that, a professional who is making off a maintenance free junction that will be hidden in the fabric of the building and become inaccessible will be on their absolute best junction box I can make off game plan.

 

[littlespark]

If you can, drop the leg between 2 existing sockets and bring your new loops back, one to each.

If not, take your new loops back to the same socket on the ring, connecting through in the back of the box for one leg, and into the socket on the other.
Fit a deeper back box if you can to make room.


I wouldn’t worry about overloading the circuit.
Worse thing that can happen is the breaker trips. (In theory)
Most big appliances will cycle on and off during any operations… and unlikely to be all full power at exactly the same time.

 

[Jock from the north]

Hello again, been a while.

I'm wanting to extend a ring final and I'm at the 1st fix stage as part of some building work to open up our ground floor. Following demolition, a 2 gang socket is redundant in place, so my plan is to extend the ring and add 2 further 2 gang sockets. To join into the ring I'm planning to use a pair of Hager 32a maintenance free boxes which will be fixed to a plate across a joist.

Other than calculations for the loading due to the increase in sockets on the ring, is there anything else I need to think about? One of the sockets will accommodate a washer dryer, but the others will be used for light loads only (at least by us).

However, as overloading can be a concern when adding sockets, I'd also be interested to know how professionals usually document the work, for the benefit of future occupiers. Both location of the cables and also which circuit they pertain to. We are taking detailed photographs, but it would be nice to have something that makes sense for anyone who happens to read it, for safety's sake and also for future maintenance.

Floor area is less than 100m2.

I do not believe any of the work I'm undertaking is notifable and we're not doing anything with the distribution board. Please correct me if I'm wrong.

Many thanks, as always.

i guess your tied for length ,rather than use a hidden jb could you add another socket some where else even if you dont plan to use it and continue your ring from there .without knowing what length you have there would be little point in ripping the rest of ground floor to bits to re route ring legs .is it a concrete floor with ring wired from above

 

[brianmoooore]

As above. Fitting additional sockets is preferable to hidden junction boxes, even if you never intend to use them.

 

[ninemaverickbars]

modifications to an existing circuit are not normally notifiable.
however they should still be tested and documented to be safe.

extending a ring in a domestic setting is generally considered not to increase the expected load on the circuit by a meaningful amount.
lets face it, most sockets are now days used for phone chargers, led lamps and a couple of tv type devices.

if at all possible i would avoid using any sort of junction that is hidden out of reasonable access, even though it may be ok with the reg's.

trace the cable back to the last junction and remove the old, replace with new.
hidden joints could cost you 10 to 100 times the cost of doing it right in the first place, when later you are trying to find/fix a fault.

also, be aware that the best DiY work is often just a little bit shy of a professional when they are having a bad day, I am not questioning your ability's but there is an art to this electric stuff that takes some time to hone.

further to that, a professional who is making off a maintenance free junction that will be hidden in the fabric of the building and become inaccessible will be on their absolute best junction box I can make off game plan.

Thanks James. Judging by the wiring locations, we'd unfortunately have to remove much more of the ceiling, part of the wall and probably half the kitchen to remove the original circuit. The wiring is all over the place and routed in such a way that it can't be pulled. The joist looks like swiss cheese because of plumbing and electrical, so we're having that looked at seperately. They've taken cores out and then put them back in. Really unbelievable. It's a 2005 new build so some of the walls are paramount board which has made it even more difficult for us to pull any cables. Horrible stuff.

From what we've been able to see during the overall works, we've tried to identify each cable and clip it up. Aside from that, as the previous socket was located in what is now the centre of the room, we couldn't see much of an option for leaving a socket in situ - aside from on the ceiling.

We've fastened the junction boxes to boards and mounted them in such a way as to avoid casual drilling from either above or below. The connections themselves seem very sturdy indeed, as do the cable clamps on the boxes.

To try and prevent future problems, we're documenting everything we've done with photo's and will hand it over to the new owners, so hopefully that will help inform them.

Edit: Happy Christmas if you celebrate the day.

 

[ninemaverickbars]

As above. Fitting additional sockets is preferable to hidden junction boxes, even if you never intend to use them.

Thank you Brian, I understand. It's unfortunately right in the centre of the ceiling with nothing below. Tracing it back, theres no reasonable chance of pulling it all out without extensive demolition. The routing is terrible as is the case with all the circuits unfortunately.

 

[ninemaverickbars]

If you can, drop the leg between 2 existing sockets and bring your new loops back, one to each.

If not, take your new loops back to the same socket on the ring, connecting through in the back of the box for one leg, and into the socket on the other.
Fit a deeper back box if you can to make room.


I wouldn’t worry about overloading the circuit.
Worse thing that can happen is the breaker trips. (In theory)
Most big appliances will cycle on and off during any operations… and unlikely to be all full power at exactly the same time.

I'm not sure we can do that littlespark, I hope I've understood correctly.

The socket needed to be removed as it's in the centre of the ceiling now, with nothing below.

Your post has made me want to go and have another look, which I shall do. Just struggling to see another way because of locations and the way the place was cabled originally.

 

[ninemaverickbars]

i guess your tied for length ,rather than use a hidden jb could you add another socket some where else even if you dont plan to use it and continue your ring from there .without knowing what length you have there would be little point in ripping the rest of ground floor to bits to re route ring legs .is it a concrete floor with ring wired from above

Unfortunately not really Jock. We're in the centre of a 6mx10m ceiling with nothing close by. I can't even be sure that the nearest socket is the socket closest on the actual cabling, as stuff is all over the place. Concrete floor and ring is above.

 

[ninemaverickbars]

I thought I'd add a few photo's of the overall situation we find ourselves in and the general standard of the building work, which is why going back to the previous socket to extend the radial was proving impossible. We have wires and pipes all over the place.

I cannot imagine how difficult it is for pro's to work in houses build like this.

I will start with my favourite pic. Dangling electrical wires near a soil pipe and free range unsupported central heating pipe to a manifold, all inaccessible and dangling. A trio of random holes in the joist for good measure. The legs dropping down, one is hidden here, but they serve sockets for the old fridge and freezer. No idea what the horizontal cable is for yet:





Engineered joists like swiss cheese for no apparent reason:


Spaghetti junction towards the edge of the ceiling, but its similar all over the ceiling. No cable clips at all, anywhere:


Only owned one size of hole cutter and no tape measure: