In message ,
"ARWadsworth" wrote:


"Set Square" wrote in message
...
In an earlier contribution to this discussion,
Gary wrote:

Robert Irwin scribbled :
As a matter of interest, is it worth putting some sort of trunking in
the
groove before putting cable in, or can I get away with just slapping
plaster
over it?

Use capping which is specifically used to cover cables.
Its just nailed over the top of the cables and comes either as metal
or plastic, plastic is much easier for cutting and fixing.


Metal capping is much safer - because it makes it much harder to drill
into
the cable by accident! Metal can be cut fairly easily with tip snips - and
held in place with galvanised felt nails prior to plastering over it.
[Even
if the walls are brick, you can usually nail into the mortar courses
without
too much difficulty].

Metal capping comes in various widths for different cable sizes. One of
the
most popular sizes takes two 2.5mm^2 T&W cables side by side for ring main
wiring. You might find that you have to go to a proper electrical
wholesaler
to get metal capping - many of the DIY sheds only seem to stock the
plastic
rubbish these days.

Most SDS drills will go straight through metal capping without you knowing
it is there and I believe it should be earthed to meet the regs.


And so long as you stay within the allowed "zones" or bury the cable
more than 50mm (you're not going to do that in a normal wall with a
channelling chisel) you don't need protection for the cable(s) at all.
Off the top of my head, the allowed zones are within 150mm of a corner
(wall/wall or wall/ceiling, NOT wall/floor) and vertically or
horizontally directly out of one of those zones to an accessory (switch
or socket).

Not entirely safe - assumes people won't put shelf brackets or picture
hooks up within 150mm of a corner for example - but withing regs
nevertheless.

On the subject of SDS channelling chisels, my £24 one from Screwfix just
broke (snapped off in the chuck). It's only had a couple of hours' use,
mainly in plaster but occasionally hitting a stone or a brick. Grrr...
time to get on the phone I think.

Hwyl!

M.

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