RE: Conduit in walls?

["James Hoye" <james.hoye@xxxxxxx>]

> I'm currently in the process of cabling my recently purchased house. 
I
> would like your advice on whether to use cable conduit or not when
> laying cat5, coax or mains cabling into the walls.
>
> What is the benefit of conduit?  Why should I use it?  I've been
advised
> to just bury the cable in the wall and fill over it.

There are several rules about cables and walls.  From _memory_:
It has to be assumed that vertically above and below as well as
horizontally
to the left and right of any switch of socket a cable may exist.  For this
reason, I _believe_ that protection isn't necessary.  This also applies
where the area is within 6" of a corner, floor or ceiling.

Otherwise, unless the cable is buried at a depth >50mm, then mechanical
protection is required in the form of earthed metallic conduit.  It states
that in reality, using this method of protection it is difficult to achieve
compliance - so it's best to install cables within the recognised areas.

This is from memory - you should consult
http://www.amazon.co.uk/exec/obidos/ASIN/0953788504/markmccall
which is very
useful.

> Doesn't the cat5/coax/mains become unmovable if a top hat section
> conduit is used?

Yes.  Also called capping.

> Is there a recommended sizing for conduit?  Or just what fits?

There's oval conduit, or you can use circular (PVC).  Common sizes for
circular comes are 20mm and 25mm.  25mm requires more chasing, but allows
more cable capacity.  One  advantage of conduit (particularly 25mm) is that
it allows you to pull more CAT5 through at a later date when you realise
you
hadn't installed enough initially :)

Use separate conduit for mains cables.

James H