Lawrence Zarb wrote:
I am going to install a ring main in my back room, and will be laying
the 2.5mm cabling in PVC conduit. Can I fit both 2.5mm t&e in one 20mm
PVC conduit, and will there be any room for a 1.5mm lighting cable, or
will I have to use 2 lengths of 20mm conduit?

What conduit are you using? Sounds like the round section stuff like
this: http://www.tlc-direct.co.uk/Products/MT20.html That is intended
to take non-sheathed wires, ie you run the live, neutral and earth wires
separately - you'll have a hell of a job trying to stuff all your
sheathed cables down there.

Can you describe your application - are you wanting surface-mounted
wiring rather than (eg) burying it under plaster? If so, trunking is
the stuff - something like:
http://www.tlc-direct.co.uk/Products/MTMIN3.html

David