ᐅ Excess Moisture in a Single-Family Home After Installing the Screed? Risk of Mold?

Hello dear forum members,

On December 13th/14th, the screed was installed in our detached house/KfW55/controlled ventilation/gas heating/1.5 stories/185sqm (1990 sqft). We have been ventilating as instructed until today. When I took a closer look today, I unfortunately noticed that

- there are water droplets on the ceiling of the ground floor at some spots,
- some wooden rafters are slowly absorbing moisture again,
- quite a few already dry wall surfaces appear wet or damp again, and
- the foil in the upper floor/attic is damp in most places.

The hygrometer has shown humidity levels between 85-95% in recent days, especially higher in the attic, of course.

On January 10th, the gas heating will be connected to start drying the screed. So far, we have not used any construction dryers or similar equipment.

Questions:

1.) Is this amount of moisture in the house normal at this stage of construction and at this time of year?
2.) If not, in your opinion, is there already a risk of mold? Or is it more likely that after the heating phase by the end of January everything will dry out and be resolved?
3.) Would you recommend setting up construction dryers temporarily as an additional measure?

I am a layperson and have no idea if this is "normal" or if we are heading toward a serious mold problem. My builder won’t be back from vacation until next week, and I want to be prepared with your assessments/comments. Otherwise, all the moisture might be sealed behind drywall quickly, and we could face big problems later. Attached are some photos. By the way, my builder is really great and very cooperative, but as mentioned not currently available.

Thank you for your input and Happy New Year 2022!