In article . com,
writes:
I am to install central heating in my house and need a single socket
for the boiler to be close to it.

Can anyone advise which is the better option -

1) To take a spur from an existing socket on a ring to this additional
socket or

2) To take a spur from a junction box intercepting the ring main. I
understand from this that I need to remove the sheathing on the cable
and strip away some casing to leave about 1/2" of the neutral and live
exposed and connect this without cutting the 2 wires. The only wire
that needs to be cut in 2 is the earth wire and then linked to the
spur.

There's no requirement to avoid cutting any of the 3 wires.
(Having said that, I do try to avoid cutting conductors that
are to be connected anyway, but it's not worth jumping through
hoops to do it.)

I think the junction box would be the easier option as I could take a
feed from the cable in the ceiling as the socket is needed half way up
a wall. The socket spur would involve a wire going down from an
existing socket into the cellar, along then up the wall.

Any advice would be greatly appreciated and many thanks in advance.

Do whichever is easiest.
Incidently, if you fit a socket for the boiler, it should be
an unswitched socket. Alternatively, install a switched fused
connection unit (which will be double pole switching).

--
Andrew Gabriel