I am installing a drive way at the back of my garden. To get level with next door's drive I need to raise my level by 40cm at one end of the proposed drive and then slope it down to meet the road at the other end. The area is concreted at the moment, should I just fill on top of this with scalpings and then block pave on top of a further layer of sharp sand as you describe in the block paving project -or do I have to break up all the old concrete first?
If the existing concrete is sound and stable Gareth there is no reason why you cannoy pave directly onto it using sand as we describe. The sub base of scalpings is to make sure nothing dips and drops causing puddles later so if the concrete is OK and you are happy with the finished level its ok.