On Fri, 29 Aug 2003 21:11:40 +0100, Ed Sirett
wrote:

Maker a pilot hole in to out and then core the hole out to in. You'll
want a 107mm drill.

Something to consider here is that when the core bit breaks thru on
the far side it can cause the surrounding brickwork to fragment a
little.

I have found it is better to drill the small pilot hole right thru,
then apply the core drill from both sides, so that the large hole
created by the core drill meets in the centre of the wall (or cavity).
That way you get a nice clean hole both sides requiring only minor
reparation.

In case no-one else mentions it, be aware that using a core drill can
cause a lot of fine powder dust. SWMBO can be useful during drilling
operations holding a vacuum cleaner hose just under the drilling area.

Andrew