Marcos Scriven wrote:

floor boards to the cuboard, and there the power socket/media box. I
will probably hire a diamon chasing machine such as this:

Make sure you get one with very good dust extraction! Failing that a
chisel bit on a SDS drill will do the job with less mess if you don't
have access to good dust collection.

1) Remove one sheet of the lining paper which is there

I think I would just cut through it and then bring the finish up to
level with the top of the paper afterwards...

2) Cut the channel with the above tool

3) Chisel out the channel with a hammer and chisel (bolster chisel I
presume?)

Yup, or a cold chisel.

4) Put in some kind of plastic conduit which will allow the cable to
enter laterally (rather than threading through) as the plugs are
bonded plastic, and wired in a proprietary manner, so wouldn't want to
have to cut them off and replace!

I would have though it simpler to put in a conduit large enough to take
the connectos as well. If you don't then you may be able to get the
cable in there without cutting it - but it won't come out again
otherwise. Look at CPC - the do conduit and trunking in all sorts of sizes.

5) Thread cable through floor board and ensure there is enough slack
both at the TV end and the cupboard end.

6) Use some kind of filler (polyfiller?) to fill in the channel.

7) Wait to dry

8) Sand as smooth as I can

9) Paste and cover with new lining paper

Done... Yeah right!

The problems I forsee, and need your advice with, a

1) How do I know the wall is strong enough for the plasma?

How heavy is the plasma? What is the wall made out of? It it is any form
of block work it should be fine. If it is plasterboard (or lath and
plaster) over studs then you may need to locate the studs for fixing to,
rather than the gaps.

2) I am not sure what to do when it gets to the skirting boards. They
are pretty old (probably 1900-1905), and I can't see an easy way to
pry them from the wall. They are a good 100-150 mm high, and 15mm
deep. I just need to get that extra distance *behind* the skirting
boards, down into the floor board void (which I can get to with the
huge 1 metre crawl space underneath)

Get a 'kin big drill bit. One of the Screwfix 1m jobbies will get you
behind pretty much any skirting. You can also get special channeling
chisels for SDS drills designed to reach down behind skirtings.

3) I am also worried old plaster/brick won't fare well with the
chasing

If cutting with a disc based chaser then it will be fine. Using a
ordinary chisel on a SDS is also usually OK. Using a channeling chisel
on an SDS is quick but will cause more collateral damage on flaky plaster.


--
Cheers,

John.

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