ᐅ Mold under the screed in the insulation layer

Hello, does anyone have experience with mold in the insulation layer beneath the screed?
How can it be detected or measured?
There are, for example, mold tests for indoor air where petri dishes are placed for 2 hours and then the level of contamination is assessed after a certain period. Does this seem useful?

Any other experiences or tips?

Another question: is it possible to seal the edge insulation strips—the gap between the floor covering and the wall—with silicone, for example (house completed 4 years ago)?

B.Beat schrieb:

How can this be detected/measured?

Open it up and check what the problem is.

B.Beat schrieb:

There are air quality mold tests where you place Petri dishes for 2 hours and then evaluate the spore concentration after a certain period. Does this make sense?

No, because this only measures mold spores in the air. You still can’t determine the underlying cause.

B.Beat schrieb:

Another question: can the perimeter insulation strips, the gap between floor covering and wall, be sealed with silicone, for example?

And what would the purpose or effect of that be?

B.Beat schrieb:

House completed 4 years ago

As I mentioned before, it’s better to identify the cause rather than just treating the symptoms. If the house has been standing for 4 years and has been adequately heated and ventilated in that time, then construction defects are more likely, not the absence of adhesive tapes on the staple boards (which are omitted in most buildings anyway).

My guess would be issues with the masonry or a faulty damp proof course leading to thermal bridges, or simply heating/ventilation deficiencies and their associated consequences.

Yes, thanks.
But opening it up isn’t that simple. The flooring would have to be removed, and the screed taken out as well, and the underfloor heating is embedded in the screed.

I also have no indication of where the problem is most likely occurring.
Our animal housemates (another post) are present in various spots.

If there isn’t a mold issue, sealing the perimeter strips to eliminate potential gaps for access would be advisable.

Sure, opening it up involves effort, no question about that. It really depends on what the goal is: investigating the root cause or just treating the symptoms.