Damp walls in the basement of a new building - construction execution error?

The site manager is still of the opinion that the moisture is not coming from the floor slab, but from a spilled bucket, a leaking hose, or something similar. This could also be possible because a lot of water was "tapped" in the area.

A fan is now being set up to dry the corresponding spot.

We will just wait a few more days now. I currently do not see any need for an expert. If the moisture remains or increases, the case is clear anyway, and then my builder will be under pressure.

It can't be coming from the base slab, you can also see that the house is not standing in the GW. I also guess that someone has muddled something with water very much, or at least I hope so for you.

Hello Earth

the structure of the basement looks good. And nowhere water that could enter from outside.
Someone made a mess. The moisture is under the screed and must be removed. A construction dryer is exactly the right thing for that. But write down the power consumption. That can cost a bit.

Steven

Hello Earth

the construction of the basement looks good. And no water anywhere that could penetrate from outside. Someone messed around there. The moisture is under the screed and must be removed. A construction dryer is exactly the right thing for that. But write down the electricity consumption. That can cost something.

Steven

That is also my assumption, but as a layperson I didn't want to write it. But it won't be done after just one week of using a construction dryer. Something like that takes longer than a few days of drying out with a construction dryer.

The construction dryer is not sufficient here. The damage pattern clearly shows that there is moisture under the screed (in the screed insulation layer). Accordingly, a screed insulation layer drying must be carried out.

Thank you for your comments and assessments. It would basically mean that it is not due to the base plate. That would of course take a huge weight off my shoulders. But I will only have final certainty once it has rained, and it would have no impact on the damage pattern.