Floating floor on damp flagstones....

[LNM1969]

I have sandstone flags in the cellar which are laid direct onto the clay. 1850's. Major damp coming through joins and at the edges. Ideally, I'd get them all up, fit ufh and replace but that isn't realistic and I doubt they would ever go back as well as they are fitted now. Removing the source of the damp would need a decent sized JCB to shift many hundreds of tonnes of soil and clay banked up against the outside cellar walls ...
Among the options is to fit a floating floor. Thick polythene with at least a 1m upstand. 150mm PIR with taped joints.
22mm t+g boards with epoxied joints.
This should leave a floor height meaning the last step into the cellar won't be needed.
Any significant issues here ?

 

[Deleted member 174758]

Your T&G boards should be P5 grade if chipboard (I assume they are), but epoxy won't give you any advantage over polyurethane glue and it will cost a lot more and be more awkward to use.

Are you doing anything about the walls? Asking as some moisture invariably comes through cellar walls

 

[LNM1969]

Got the receipt somewhere, said moisture proof iirc. Ye re glue, I've used poly on some boat repairs recently and the join when cured was stronger than the wood...Just bog standard Puraflex 40.
Walls; going to construct a warm box inside the cold one, with (albeit limited) access round the outside.
Ta for reply.