In article ,
"Dave Plowman (News)" writes:
In article ,
Andrew Gabriel wrote:
But surely you've got to make good where the wires cross the wall, so
what's the point of making the hole perfect?

If you're looking to not make a mess, then you don't make the
wires cross the wall. You come through from the back, or drill
from the back of the hole steeply down to come out on the other
side under the floor, or maybe you're swapping out a single for
a double socket. For data/phone wires, I've used an 8mm 18" bit
to drill down from the bottom side of the box to under the floor,
and then drill into the wall under the floor to meet it with a
20-25mm bit so you can get your finger in to coax the wires out.

Of course there are instances where this might be possible, but in general
you'll be needing to route two 2 X 2.5 TW&E The chances of making holes
for these from the box cut out to under the floor I'd say is near zero. ;-)

In thermal blocks, it's easy.
In anything else, it's a lot less likely to work.

--
Andrew Gabriel