I' building an office / workshop at the bottom of the garden. I need to lay electric, water and phone supplies about 20 metres.

I'm happy enough to use armoured electric cable in an 18 inch deep trench, but for belt and braces was planning to feed it through a plastic conduit.

My question is this. can i feed to phone cable through the same conduit or will there be interference? if so how far apart do the cables need to be?
???

Dont use conduit.  Use proper electrical DUCTING, continuoes legth on a roll is best, no joints to snag on.

Interesting Plug - I thought that the Water Regs (for MDPE) was same as IEE for cables - 750 mm.

RR

there is no minimum for cables people- its interpritation unless he is having a seperate new metered supply to his shed.....would have thaught it was a submain from house...

ss

to be buried at a depth that will prevent unintentional damage (or some wording such like)

no, i thaught the minimum was removed, infat im 99.9% sure that it has been.
lectrician is about right with the wording, its upto you to decide


ss

not if your any good LS not gunna stick a cable at 2inch under a flowerbed are ya!!!

only place ive seen cables at 750mm was when the rec dug up the street by a sub near where i used to live, and that was 11kv swa

ss

Cables to be installed in ducts or pipes in the ground
are not required by BS 7671 to have armouring and/or
a metal sheath, if the duct or pipe is sufficiently
strong to resist likely mechanical damage. In case of
doubt, a cable fulfilling the requirements of
Regulation 522-06-03 should be provided.
Protective conductors which are buried directly in the
ground must comply with the requirements of
Regulation 542-03-01.
All buried cables must be marked by cable covers or a
suitable marker tape, and buried conduits or ducts
must also be suitably identified. A warning tape
above the duct or conduit run would be suitable.
Cables, conduits and ducts must be buried deep
enough to avoid being damaged by any disturbance
of the ground reasonably likely to occur. This could
include gardening/horticultural works, excavating for
any local buried service pipes etc. Generally, it is better
to locate cables etc. clear of such possible works.

A depth of burial of less than 500 mm is usually
inadvisable as shallow laid cables may be
inadvertently damaged by general gardening etc.
Cables that cannot be buried at a reasonable depth
should be specifically protected, e.g. by ducts encased
in concrete, or installed along an alternative route.
Before any excavation is undertaken for cable or
other works HSE guidance booklet HSG47 "Avoiding
danger from underground services" should be
studied, as it provides valuable advice on safety
aspects.
It is important to be able to identify exactly where
hidden services are located and accurate records,
including drawings, should be made before trenches
are backfilled. Cable routes should be located on
drawings by dimensions from some fixed object that is
not expected to change for a considerable time, (e.g. a
building). Road and pathway features may be relatively
easily changed. Scale drawings are of little value unless
very detailed. Concrete route markers may be installed
at changes of direction of cable routes and at regular
intervals along routes.  

PS Where is the fcuking kek to the front door wabbit

Cheers peeps,

I guess if I collate all the advice and use the most stringent - I'll come to no harm.
so it looks like a trench three feet deep - three feet wide with 2inch thick concrete pipes spacea at least 12 inches apart with an itty bitty caple (or pipe) in each.

I think I'll move the workshop a little nearere the house