Hello,

What is the best way to chase walls for cabling? I read the wiki FAQ
and it talks about making two lines with an angle grinder and then a
bolster chisel to knock out the bit between. That's what I have been
doing. I am using a 115mm angle grinder which is cutting about an inch
into the wall. That's as far as it will go. It's cutting about 10mm of
plaster and 15mm of breeze block. Is that deep enough or do I need to
use a chisel to go deeper?

The angle grinder is making some nice deep lines, but I am not getting
a clean cut of the gap between the lines. The breeze block is very
rough. What is the best way to get a smooth finish? Do I need to
sharpen the chisel? Could it be blunt?

What is the best thing to drop the cable in? Wickes & Screwfix sell
some channeling, which is a bit like a gutter. The problems I see with
this a
1. plaster could get round the back and onto the cables or block the
channel
2. the wire could scrape against the rough surface of the wall

Wickes also sell the same in metal. I guess the metal offers more
protection against drilling/nailing through the cable but does it have
to be earthed? If it became live I cans see that could be very
dangerous.

I see the wiki uses proper conduit, which would avoid both of my
problems above, but if it is 20mm in diameter, it would only be 5mm
beneath the surface. Would that be deep enough? How do you hold it in
place whilst the plaster sets around it?

Thanks,
Sam.