ᐅ Interior insulation with udiin, experiences

You previously wrote:
"....one must therefore use a vapor retarder and be extremely careful to ensure it is properly connected."

However, if the product already supposedly includes a vapor retarder, the homeowner does not need to worry about using a separate vapor retarder or properly connecting it to the insulation...

Furthermore, the product in question here – as well as other vapor-permeable products (such as the one from STO) – does not contain a vapor barrier layer. During installation, it is important to ensure that there are no gaps between the insulation material and the cold exterior wall (this can be achieved using special adhesives), and that no vapor barriers such as unsuitable plaster or "airtight" paint are applied. For optimal moisture regulation, a clay plaster is recommended, for example. Therefore, your argument (quote: warm indoor air cools down at this point between the insulation and exterior wall, leading to condensation) for an additional vapor barrier is unfounded.

Minimal water condensation can dry inward through the vapor-permeable insulation; there are calculation tools available to determine up to what extent this works reliably.

• Without vapor-proof materials, the indoor climate and moisture transport between inside and outside are regulated naturally and physically

Well, with a U-value just above 0.5, the whole discussion about dew point, diffusion, adhesion, vapor barrier, and light incidence is basically unnecessary.

Whether inside or outside, and whether 2cm (1 inch) or 20cm (8 inches): IT NEVER pays off! So just leave it, save work and money, and focus on other weak points instead (roof, windows, basement ceiling, radiators/temperature, thermal bridges).

That's a completely different matter, but I totally agree with you. Financially, that usually doesn't make sense.

Thank you very much for the responses

Mike99 schrieb:
Thank you very much for the responses

Best regards from Loriot.