floating floor for limestone

[Chalker]

Keep the current insulation

I get you now...

But isn't that still a floating floor?

 

[AliGage]

No as its fixed to the substrate.

 

[AliGage]

You could cut 50mm timbers into the insulation and fix to floor.
Screw your double skin of ply to these.

 

[Ajax123]

You could take up the chip board put a polythene slip membrane on top of the existing insulation and put Down a 45mm anhydrite screed.