concrete slab/floor

Away to lift a floor in the house (was a kitchen originally but changing it to a living room) current make up of floor is flagstones, covered with bitumen resin then a 40mm screed.

I propose to lift existing, scrape it back a bit, lay 25mm sand blind, Dpm, 75mm kingspan then a concrete slab made with 10mm ballast onto which I'll directly lay my finished floor (underlay and engineered oak) I don't want to have to lay a screed on top of concrete.

My question is what minimum thickness of slab would I get away with and would it have to be reinforced?

Thanks for any help

100mm min. and no reinforcement necessary but you could use mesh if you feel its needed.

Use delivered and barrow'ed-in pour, its much easier.

remember to use edge insulation between the slab and the surrounding wall.

You must work to the FFL line.

That's what I was looking for cheers