Insulation still tight despite UV exposure (2 years)

Hello community,

We have newly bought the house and are currently dealing with the insulation between the concrete basement and the prefabricated house (timber frame construction).
The previous owners built the basement themselves, and the construction company then placed the prefabricated house (timber frame construction) "on top" of it.

Now the insulation has basically been as open as in the pictures since 2016 (between the basement and the house). The Styrodur boards are already yellowish (you can easily wipe it off, then the white comes back).
Can we simply scrape off the yellow coating and put a black dimpled foil over it again, or does the insulation performance suffer due to UV exposure?

Also, the boards really smell toxic when the sun shines on them. I can smell it myself even if I just open the terrace door. I guess they are simply not made for UV light.

Info: The gap is supposed to act as a so-called "breathing joint", but a lot of heat is lost in winter because of it... Does anyone have experience with breathing joints?

Many thanks to you construction heroes

Best regards from a construction layman.

Minuk

Basically, such systems are not suitable for UV radiation. In the pictures it still looks good. What is concerning is that the foil is coming off the house wall. So simply reattach it, put on the finishing strips and fill it in to bring some peace there. No real concerns, but it is getting worse with each day.

Basically, such systems are not suitable for UV radiation. In the pictures, it still looks good. What is concerning is that the foil is coming off the house wall. So just reattach it, put on the finishing strips, and fill it in, so that things settle down there. Concerns rather no, but it gets worse with each day.

Thanks. We can do the external insulation ourselves and will start it soon. At one spot, water might have gotten between the foil and the wall. Is that dramatic? Oh, and there are Styrodur boards in the basement - I think we can use these for insulation without any problems, right?

Regards minuk

Hello Minuk,
of course the boards are still good, no problem. And the water is also finding its way out again. You just have to work properly and also fill in, so that there will be a regular use.
Best regards, Vicky