r896neo,
Thanks for the reply.
Looks like I'll have to hire a demolition hammer to break up the old sub- base.
Do you know how deep the drain covers are likely to go? I'm worried about using a breaker around them.
Is it possible to use screed/pointing material as the SURFACE of a patio?
I removed the broken crazy paving from our 6 m x 2 m patio in preparation to lay 400mm x 400mm slabs. I thought that all of the sub-surface was friable (the first bit I uncovered broke up easily). But it has turned out...