The Brew Cabin

I am having my drive re-laid with block paving. The contractor specified 50mm of sharp sand as the bedding layer but I have checked the sand thickness adjacent to the laid blocks of the part finished work and find that it is up to 100mm thick. I phoned the contractor who said that the sub base is very solid, which I believe is true(old sub surface of gravel drive + 50mm hardcore + approx 50-75mm lean mix concrete all vibratory rolled).
And that 75 - 100mm of sharp sand, properly compacted, will never move. Do you agree with his reassurance? He should be on site tomorrow, 22/6/02 and I will discuss it with him then.

No! That is way too much sand and it will settle, regardless of your contractors' assurances.

BS 7533-3:1997 stipulates a bedding layer of 35-50mm, and we know from experience that anything over 60mm is terribly prone to channellisation (rutting). Your contractor should make up the levels with lean-mix or DTp1, not with extra sand.