Insulate concrete ceiling upper floor

Now I have been able to convince the energy consultant (after a call to KFW) that material is also subsidized if it is properly installed as skilled labor. Oo

But I understood it in such a way that with the PUR insulation boards 160mm I could save the effort with the vapor barrier. I will now request an offer.

Even if I were to use the cheaper Styrofoam EPS 160mm WLG040, I would still end up with about 10 EUR / m2 for the material and not even achieve the same U-value. So I do need a vapor barrier, right?

Google and play with the Uwert calculator.

By the way: especially with mineral wool, no vapor barrier is needed. Moisture can diffuse very well if necessary.

Just bad luck if it’s not the last layer and really bad luck if OSB boards are still to be installed, which are then glued, and then the vapor barrier is on the outside,...

Just bad luck if it’s not the last layer and really bad luck if OSB is still going on top, which then gets glued and then the vapor barrier is on the outside,...

Why are you so skeptical? What factual reason is there for that?
Explain your comment regarding the Bauder system structures or building physics. I am just an amateur with 20 years of real estate experience and am happy to learn more. I only learned from DIN 4108-3 that a vapor barrier or vapor retarder is not necessary.

Just bad luck if it’s not the last layer and even worse if OSB will be added on top, which will then be glued, and then the vapor barrier is on the outside,...

You have already read my initial post, right? I plan a) to create only a PARTIALLY walkable area (with OSB or chipboard) and b) I could use a vapor-permeable adhesive tape for the upper side. Furthermore, I will also choose the OSB or chipboard to be vapor-permeable. From my understanding, the moisture should then be able to escape.

Furthermore, my concrete floor has been in the building since its construction in 1972 and certainly no longer contains residual moisture. In the case of a new build, I agree with you – here one should probably install a vapor barrier on a concrete ceiling, as it still contains residual moisture that will escape.

Correct so far? Otherwise, please clarify for us in a factual way and WITHOUT sarcasm. Thank you very much for your contribution.

Best regards

@nordanney
You can still learn after many years. Bauder follows the DIN and therefore has a vapor retarder in the system.
Factual: Water vapor diffusion-equivalent air layer thickness, which must decrease from the inside to the outside.

@chippy79
Then it applies to the walkable area, b) is nonsense anyway, because the joint is not sufficient as an area.
I am not talking about residual moisture, but water vapor, since I assume the house is inhabited.