Install click vinyl despite possibly too high residual moisture.

It can happen if the screed is treated incorrectly, for example in the current weather just leaving all the windows on tilt and then not going there for 3 weeks.

But whether the screed has warped or not can be easily checked. Take a long spirit level and lay it from the wall into the room. If it’s level, where would anything still settle? ;)

Why are there settlement cracks in new houses? Because it settles. And that’s why the screed settles too. Or the walls.
Or the insulation material underneath is still being compressed a bit?
We had perfectly level screed, nothing was warped. Still, the floor partially sank. Differently in the rooms. I just resealed pieces between tiles and skirting tiles in the hallway because there was a gap. But they were only about 2 meters. It’s also partly like that in the other rooms. In the utility room, for example, where the heavy shelf with drinks etc. stands.

Or because of botched work... Settlement cracks in new houses are not a law of nature. Of course, it's often sold that way, I know that ;)

Why are there settlement cracks in new houses? Because they settle. And that is why the screed also settles. Or the walls.

When everything settles, a floating screed slab laid on insulation layers only cups or subsides at the edge areas. This is due to drying and is related to the screed binder. But if massive components of a relatively new building, including residential buildings, settle, then that is a sign of insufficiently compacted subsoil. Old buildings settle more than new ones because we have to consider the environment of the subsoil. Any foreign body introduced into the subsoil (e.g. a basement of a house) can lead to a diversion of groundwater flows. Also the compaction of neighboring subsoil by heavy construction vehicles. But with screeds, an actual "settling" of the screed slab is not known in technical circles! Perhaps in this regard we are actually talking about "reverse cupping" of a screed, as would correspond to the technical terminology? ----------------------- Regards: KlaRa