Underfloor heating: Errors in laying loops by a professional

Yes please more info... how high is the insulation above the planned etc.

So that I understand correctly... The general contractor provides planning, insulation, underfloor heating, and payment?

Communicate concerns in writing to the general contractor... that’s his problem, he has to solve it. And he must prove to you that his behavior is professional. But it will be difficult if the screed layer himself already raises concerns.

I wouldn’t do or touch anything myself.

This is what it looks like...the GU/GÜ is obliged...

I wouldn’t touch anything now...however, you now have a considerable leverage to get the construction much cheaper...