Owain wrote:

Put one socket in the vertical chase, have one of the drop cables broken
to connect the new socket, have the other drop cable electrically
unbroken but running vertically through the box. A double socket should
be wide enough to span the chase with ample spare width for non-vertical
tolerances.

Thanks Owain that seems the best way of doing it. I wasn't aware that it
was OK to run the cable through the box like that.

In practice, unless you can pull some spare cable length from the
floor/ceiling near the socket, you may have to break and reconnect or
extend both cables - insulated crimps would be the best way of doing this.

The way I proposed had the advantage that there would have been enough
cable to go to boxes either side of the chase but it is no problem to
join extra cable if I have to as I have the insulated crimps and proper
tool.

Using an extra depth backing box would provide more room for the gubbins.

Yes, I could sink a deep box there. As the crimps are protected by the
box and accessible would I still need to cover the complete join in
heatshrink?

Another idea... could I take both cables vertically into an empty box
(with cover) then take them out horizontally to sockets either side i.e.
just using the box to indicate the cable run and provide a means of
changing direction? This would save making extra joints for the price of
having a blank single box between the sockets which won't be seen when
behind furniture.


Cheers

Steve