JK wrote:

OK, Thanks to everyone for some really helpful advice. I'm coming round to
the idea of cutting a trench and then maybe injecting if that doesn't solve
it. I already have a small angle grinder so I guess I need to stop being so
wussy. Something to do over christmas anyway!



The thinh youi need for most concrete is indeed a specialised form of
angle grinder. I hired one some time ago to cut therough a concrete path
and install underground incoming mains cable.

I hired it and its 110V trnsformner for a couple of days. It tookk me
finally once i got teh hang of it about 2 hours to cut a 4 ft long
section out of 4-6" thick concrete. No way an anggle grinder of the
hobby variety would do that.

No special safety equipment is needed apart from some eye protection. I
wera glasses thes days anyway and they were enough.


Thanks again,

John