Block paving advice - Lack of depth/fall

[dodge50]

We plan on laying a block paving patio following a recent extension. After removing our old decking, we were pleased to find a good concrete base underneath, however upon putting up lines and working out depths, it appears we have very little to play with. We only have 200mm between the top of the dpc and concrete base, leaving us only 50mm. The concrete base is up to 5" in places and going to be a nightmare to break up, and we have an added problem in where the previous owners had a smaller patio, there is no fall. The area we wish to pave is 5m from the house x 3.95m wide, so working on a fall of 1:80, we need 62.5mm as a minimum and even that is going to be a push. Can anybody come up with any suggestions, or know of anywhere we can get a slim tumbled block, if such a thing exists ? What is the minimum depth we can lay on if we were to find a thinner block ? It is a patio so will only be light pedestrian traffic !
Thanks

[TheRockConcreting]

You could use tiles.

[lutonlagerlout]

run a linear drain 100mm down from DPC to a soakaway
then have your paving fall away

local authority let us use that as a workaround in these parts

LLL