On Fri, 04 Sep 2009 09:42:14 +0100, "Dave Plowman (News)"
wrote:

Did you try drilling through again from the other side?

Yes, and it came out somewhere else on the other side. I had a wall
that looked like cheese, it was a complete disaster!

I'd tend to use a drill quite a bit larger than the pipe and sleeve it
with PVC where it passes through the wall

I was going to use overflow pipe to sleeve it but never got that far.