Patio re-laying rip up or screed over?

[rfisher]

I have an ~35m2 concrete slab patio which has moved over the years (clay soil) and needs replacing.



Lifting the 70 or so 150lbs slabs would be a lot of work, even to break them up to use as part of a new base.

Is it reasonable to assume that all movement that is likely to occur has already done so, and just concrete over the existing patio to use as a base for laying new slabs.

I reckon there would still be 1 course below the dpm at the house and would leave a drainage channel along that edge.

Bodge or acceptable approach to a nice new patio?

[rfisher]

Thanks.

Slabs are ok but have tilted or dropped in several places.

Base is probably sound so I may lift and replace with more stylish stone.