Insulation between PVC and planned vinyl flooring

Dear forum members,

my father-in-law has screed as the subfloor in his apartment, and on top of that lies a PVC layer as thermal insulation.

The apartment is on the ground floor. Below the apartment are basement rooms. He wants to lay a vinyl floor on the PVC layer and asks which material would be best to place between the PVC layer and the vinyl floor for thermal insulation against the cold from the basement. Would you recommend vinyl flooring with or without impact sound insulation?

Thank you for your help!
Best regards,
M

Vinyl is also PVC - only the name sounds fancier ...

If it should be warm underfoot and insulated, I would rather choose cork flooring than any form of plastic.

Thank you very much for your reply!

Hello "Muck1956". If you do not want to go the way of self-deception, please note that as thermal insulation for a floor above an unheated space, you will certainly need a thermal insulation layer of several centimeters. Providing exact numbers here requires a calculation of the overall system, which also includes materials (referring to the concrete ceiling, screed, etc.), their thicknesses, and the surrounding temperature. Substrates under elastic floor coverings, insofar as these have been laminated by the manufacturer, serve to minimize impact sound. Not thermal insulation. The insulation is always located beneath the screed or beneath the basement ceiling if installing the insulation within the room itself should prove problematic. The thermal insulation, if it is to live up to its name, must have at least a thickness sufficient for it to perform its function. And with only a few millimeters of thickness, you don’t need to start the computer to already recognize that it’s a "lost labor." And will only result in a multitude of impressions appearing on the (new) covering surface afterward, which nobody wants! If you fear cold feet in the situation you described, only thick socks are advisable. But under no circumstances an experimental field where the new top layer would be sacrificed pointlessly! --------------- Regards: KlaRa

Klara, my father-in-law thanks you very much! Really, thank you for your contribution!