Subfloor battens for solid wood planks + plastic wedges leveled

We are getting a plank floor. This will be screwed onto a subframe construction. Insulation will be placed between the battens. To achieve the correct level, all battens were leveled with plastic wedges. That means all the upper support beams now rest on such plastic wedges. I have serious concerns whether this plastic will last as long as my beautiful floor. Plastic ages and eventually becomes brittle... that is my fear. Then the upper battens will sag. I would like your advice on whether my fear is justified. Best regards, Steffi.

Quite harmless there. Plastic is decomposed by UV light. But it will be dark there soon.

Afaik it has to be like this to reduce impact sound. Is this an existing building?

I had to google what afaik means first... I've never heard it before...

No, it's a new building, underneath is the slab.

Best regards Steffi

Ps. I think my question fits better in the category [Materialien]. Maybe an admin can move it?

Hello,

don't you have underfloor heating?

Correct, in the hallway area we only have radiators. Underfloor heating is only available in the tiled area. Best regards, Steffi.