Recognize the quality of basement finishing

Hello everyone,

we moved into a house from 1980 a year ago. About 10 years ago, one basement room was converted into "living space" by the previous owner; there are also relatively bright windows and a heating system. Now I am considering setting up my office there because it is simply too warm in the attic (despite new insulation).

I don’t know how and by whom the conversion was done back then, but probably by professionals, not the previous owner. The ceiling has a wooden paneling, the floor also has a construction, and on two exterior walls there is classic wooden paneling with Styrofoam behind it. I once opened a spot and looked; everything appeared dry and clean. Behind the wood comes directly the Styrofoam (4cm) and behind that directly the wall. Now to you here the questions: 1) Is it okay to do it like this with wood + Styrofoam (and nothing else) on the exterior wall? 2) Is it also okay on the floor? (I haven’t checked yet, but there is a 2cm structure there as mentioned) 3) Do you generally only have to worry if the wall gets wet from outside and/or the humidity in the room is too high? (this is always below 70%, mostly a bit above 60%, no matter how I ventilate – and on one wall no rain can get to it because of the roof + terrace)

The room is okay so far – there was only a little mold once on the outside of the wooden paneling when I had a cabinet standing directly against it for a few weeks. Otherwise no moisture problems.

Thanks for an assessment!
Regards
Peter

Interior insulation is not a problem in itself, it just should not be able to be flowed behind. Also placing furniture directly in front of exterior walls is not so good, as you have noticed, because air circulation is then restricted. The radiant heat has difficulty getting behind the piece of furniture, and the exterior wall absorbs the heat from the air in the gap, so that moisture can condense. Better to leave 10 cm distance or not to fully block the exterior walls. Or place the furniture so close to the wall that no flow behind is possible again. If no warm moist room air can get into any gaps, then no moisture can condense on cooler surfaces. 2 cm floor insulation is quite little for a heated room against the ground. During the renovation we had to apply 10 cm insulation (and 6 cm of that in WLG 022) to reach the minimum value according to the Energy Saving Ordinance 2009.

The room seems to have been completely fine for several years. There was once a mold problem which was caused by negligence and has since disappeared.

Are you trying to determine if the substance is okay as it is? In my opinion, you should just use the room. There don't seem to be any problems. If it gets too cold in winter, you can consider adding more insulation, but if that's not the case, then everything is fine?

I wouldn't worry about it at all as long as everything is dry as described and no mold is visible (among other things by musty smell).

Hello you two and thanks for your answers. Yes, for me it’s primarily about whether it was okay how it was done. The topic somehow still fit best under "Bauschäden" because I just don’t know if there could be a problem or not. I just read on the Internet that you should never do that with Styrofoam on the exterior wall. As I said, it looks neat, but there is only wood cladding + Styrofoam and nothing else. The Styrofoam is directly against the wall. - Can that work like that, or is that almost always problematic? (The floor has at least 4cm build-up anyway, which material I have to check.)

Whether this is standard or whether it is "Pfusch" I cannot judge. If everything is good, I would ultimately not care much about it.