Sub base, edging, haunching depth

[pgs]

Trying my hand at block paving for the first time, and I'm finding this site brilliant. One thing which isn't clear though (to me anyway)....

Once I've got my subbase compacted down, I'll have around 80mm free above it - 50mm for the paving, 30mm for sand. But this site is saying that the edging should sit on at least 75mm of concrete haunching - I'd only have 30 (once you take of 50mm from 80mm).

Should I have less (or no) subbase under the edges where the edging course will go? If so, how do I manage to do that?

[r896neo]

Most people would lay any kerbs or edgings on concrete directly onto the sub grade/ earth rather than on top of the sub-base.

This is made easier by the fact that they would normally be put in first.

In your case just dig out any sub base you need to get a 75mm bed.

[pgs]

Cheers. I was worried that when I come to whack down the sub-base it might weaken the haunching for the edging. But I think it's going to be ok ...