Is it sensible to use a dehumidifier after taking over the building or just ventilate by opening the windows?

Hello everyone,

we are considering investing some money and buying a dehumidifier. In our case, the building handover has already been completed. The man from the [Blower-Door-Test] said that there is still a lot of moisture in the house. You can also notice it when you enter the house or ventilate extensively.

However, we are wondering if a dehumidifier still makes sense when the painting work has already been completely finished? Or is it counterproductive because somehow the paint is deprived of water or ...?

Or is ventilating enough? Regarding ventilation, we take turns with my parents-in-law since we basically commute between three places. One day I go early before work and ventilate with all windows open for 15 minutes. Then the same again in the evening for another 15 minutes. The next day the parents-in-law ventilate, but only once for 15 minutes. The next day I do it again, etc. On weekends we ventilate more often when we are there, 3 to 4 times.

Or does a combination of both bring the best results?

Thanks a lot for your help.

After painting, it is always a bit more humid. But I have never heard of anyone setting up a [Bautrockner] because of that.

The paints are supposed to lose their water. They are mostly acrylic dispersions; the water is just a solvent, after drying, acrylic resin remains. If you don’t live in it yet... we also borrowed two professional dryers from BU for seven days after painting before moving in, which really made a difference. We had the impression of moving into a relatively dry house. Of course, there is still water inside. But it’s no longer a big problem. However, drying cracks due to shrinkage can never be completely avoided. Karsten

Moisture will be an issue during the first year, even if you don't feel it. In the past, buildings were allowed to dry naturally for half a year or people simply lived in dry conditions (not earlier ;) ) That's why the floor also sinks by up to one centimeter. But why buy a dehumidifier? Rent a good one for 3-4 days, that's enough.

Moisture will be an issue throughout the first year, even if you don’t feel it. In the past, people would let the building dry naturally for half a year or live in it dry (not earlier ;) ). That’s also why the floor settles up to one centimeter. But why buy a construction dryer? Rent a good one for 3-4 days, that’s enough.

3-4 days is supposed to be enough? Before the building inspection, several dryers were in use and not just for a few days. I can’t say exactly, but I’d estimate they were running for about 2 weeks. The underfloor heating has even been running longer. But the guy from the blower door test still said there’s a lot of moisture inside. Well, I thought about buying because in the end it comes out the same. If I rent one again for 2-3 weeks, including pickup or delivery, it’s about the same price as if I buy a unit myself for roughly 350 EUR.

How does the floor behave if there is still that much moisture in the house? Can I already start laying the floor (vinyl - click variant)? Or is that rather irrelevant with regards to the moisture in the house? Hope you understand what I mean :)

And also regarding settling: does the floor settle evenly or more in some spots and less in others? Will I end up with an uneven floor?

The paints are supposed to lose their water. They are mostly acrylic dispersions, the water is just a solvent; once dried, acrylic resin remains. If you don’t live in there yet... after painting and before moving in, we also borrowed two professional dryers from BU for seven days, which really made a difference. We had the impression of moving into a relatively dry house. Of course, there is still water inside. But it’s no longer a big problem. However, drying cracks caused by shrinkage can never be completely avoided. Karsten

Thanks Karsten. That helped me. Well then, it seems a dryer afterward is no problem. But does that also apply to the vinyl floor? Or can something still warp, causing the vinyl to warp or lift or whatever? It’s click vinyl without such a wooden carrier board inside. My questions may seem quite crazy, but they mostly come from my wife, who has also made me a little uncertain :(