Domestic Wiring Question

[Nodge]

I'm about to do up our upstairs bedroom which will involve fitting a couple of new sockets. The wiring in our house is very old and none of the upstairs sockets are on a ring main. I believe the mains cable goes from the consumer unit under the stairs, under the lounge floor, up the wall to a wall socket in the front bedroom. 2 cables run from this - one to a wall socket in the back bedroom and from there to another wall socket. The other cable runs to another wall socket in the front bedroom and then under the partition wall to a socket in the small bedroom. I want to add another 2 sockets in the front bedroom. Should I just wire all the sockets one after the other (as if they were on a ring main), just ending at the wall socket in the small bedroom?

At some time in the future I may also want to add some more sockets to the back bedroom.

No doubt the best thing would be to actually fit a ring main but the lounge floor cannot now be moved and there is no easy access to run a cable up under the stairs to the landing.

Nodge

[meow2222]

You can use radial wiring as long as the fuse and cable size are suitable.

NT

[Christian McArdle]

You can run them in a line, or branch off as a tree. You can wire them in any configuration that doesn't loop back on itself.

There is no need to convert to a ring. You have a radial circuit and it can happily remain this way.

If this circuit is run in 2.5mm PVC cable (or its imperial equivalent), then it is suitable for an unlimited number of sockets, provided that it is fused/MCBed at 20A (you may need to swap a 15A fuse for a 20A MCB) and provided that the floor area of any rooms it covers does not exceed 50m2.

If the cable is old rubber stuff, then DO NOT touch it. It requires rewiring and, in the meantime, should not be touched, as this can cause the brittle rubber at the terminals to disintegrate.

Christian.

[Guy King]

The message from "Christian McArdle" contains these words:

So much so that in the house we used to live in the wires were no longer insulated for the last inch or so as they came out of the conduit - just bare where the insulation had perished. Scary.

[Fash]

I thought/think the limit for floor area for a radial socket circuit is for the total area served not for the individual rooms, otherwise you could put in a radial that covers a larger area than a ring which is only allowed to cover 100m2.

What's the lounge floor made of?

If your downstairs sockets are on a ring then you could break the downstairs ring between two sockets and go vertically upwards from each to the upper floor (you can then take wires horizontally provided they are within 150mm of the ceiling) and extend the downstairs ring to cover upstairs. If the downstairs ring is newer this might be safer and then disconnect the old radial at the CU and remove what wire you can easily get at.

Whilst not strictly necessary to update if you're putting a lot of effort into doing up the rooms it may be worthwhile sorting out the wiring properly rather than just bodging on to the end.

Fash

[Christian McArdle]

Yes, I meant the total area. I just expressed it ambiguously.

Christian.

[Anonymous]

I wondered what the trail of dust was in my roof, when I moved in 20 years ago.

Picked up the bits, only to find some strands of wire.

This was my lighting circuit to the bedrooms.

I wondered why the rewireable fuse in the box was black and sooty.

[Owain]

Would squirty foam up the conduit be acceptable as a temporary measure? ;-)

Owain

[Guy King]

The message from Owain contains these words:

[meow2222]

Flash! Aaaaah! Destroyer of the universe (to music)

NT

[Adrian]

Talking of 'squirty foam' - I've had a couple of the big Screwfix aerosols of Squirty Foam in the garage for a couple of years.

A couple of days ago we had an invasion of flying ants - turns out they were coming in through a 22mm home in the brichwork for a 15mm cold water pipe.

Aha - I thought - squirty foam into the cavity - fill both holes at the same time (inner & outer 'skins' of the wall).

Unfortunately I had to resort to 'universal' Polyfilla - becase I couldn't get the cans to dispense foam. There's some in there, cos I can hear it sloshing about when I shake the can - but I can't get any to come out of the nozzle. The most I could achieve was to get some to leak out around the seal between the valve and the can....

It's been a while since I used this stuff, do you need to pierce a seal in the nozzle before it'll foam ? Thought I'd ask before I tried, cos I didn't much fancy being on the receiving end of a jumbo-can-full of uncontrollable foam.....!

Thanks Adrian - Suffolk UK

[Guy King]

The message from Adrian contains these words:

I've had exactly the same problem. Unused can, about six months old, wouldn't dispense at all.

[Adrian]

Aha - it's not just me then.....

..trouble is - I bought the (3 or 4) cans at least a year ago - possibly longer - so I doubt Screwfix'd be interested in exchange / refund.

Thanks for letting me know

Adrian

[<me9]

Having just bought a new can to seal round a profesionally fitted window (that makes 'ghost' noises in windy weather due to not being sealed properly), I investigated a part used can of Wickes foam, which had an expiry date of 2004. Is sounded different when shaken, so I gave it a good shake and cleaned out the dried foam in the nozzle. It then worked perfectly. I now need to find a use for the new can before it solidifies in >2 years time.