I'm in the final throes of bringing the house into the modern era and
in terms of electrics all that remains is updating our living room and
dining room sockets.

The current sockets in the l/room and d/room (all three of them) are
on a radial circuit, with the cable from the CU looking to be about 4
or 6mm.

Currently the cable runs from the CU in a cupboard, through a pipe
under a solid (ornately tiled) hall floor emerging under the suspended
floor in the dining room. The length is approximately 3.5 - 4 meters
to that point.

When fitting upstairs I installed a new ring and led the ends back to
the CU. A spark came along and tested the new cicuit before
connecting it up, thus saving me lots of money on donkey work (lifting
floorboards, chasing brick etc.)

If I were to do the same downstairs I seem to have three options:
1) Stick with a radial circuit and use the perfectly good chunky wire
that's already there. This will require SWK to help with the maths so
I know how many sockets I can install.

2) Ignore current radial and run new ring, travelling through the
ceiling void crossing the whole house, before coming down an exisiting
service duct into l/room then run as ring like normal. Downsides are
that this uses a lot more cable.

3) Extended upstairs ring to include downstairs so that all sockets
are on one ring. Again this would need careful calculation to make
sure I'm not exceeding limits on potential load and cable length.

4) Combined ring/radial. Does such a concept exist? Have I entirely
missed the point? Is there any merit in attaching a junction box to
the old radial cable where it enters the under floor void in the
d/room and then running a ring of 2.5mm cable around downstairs?
Presumably the limiting factor is the size of the existing length of
radial? Obviously you use much less 2.5mm cable and don't have to
cross the span on the house through the celining void. You keep two
seperate circuits for upstairs and downstairs.

I may be able to squeeze a bigger individual cable through the
underfloor pipe but I wont be able to fit two 2.5mm.

I'm undecided and don't have enough experience to make an educated
decision. The simplest thing is to run a new ring across the house.
The next simplest (but less cheap) option is to just ask Mr Spark to
do it. I don't know what the BEST solution is.

Any help gratefully received.


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Steve F