HPL facade panels show dents in the center and around the screw holes

Thank you for your assessment, danixf.

We had suspected something along these lines as well. Our builder is now seeking direct contact with the roofer and will get back to us. However, I suspect a confirmation of the statement "there is no other way because otherwise the panels will rattle." This is what we heard most recently.

.... we are waiting for an answer from the roofer about which manufacturer he ordered them from.

I also think it is as says. Possibly the substructure is also insufficient. In any case, the screws must not be tightened too much.

"that's not possible otherwise"

Yes, it is!
Don't let anyone tell you otherwise, that's nonsense; you can see it. Just imagine a whole wall of a school or office building like that...... :eek:
The manufacturer will also tell you something about the "rattling".... otherwise whole districts would be rattling.... oh dear

We are also quite appalled by the initial reaction... another manufacturer said that when drilling, you also have to make sure that the drill bit doesn't get too hot.

We have really only experienced, with just one single exception so far, that you can no longer rely on any company - no matter how reputable it is presented to you.

Trespa is not the only manufacturer, even if it is another one (Resopal or similar), they all have precise installation instructions and various alternative fastening options (to prevent rattling). It is simply poorly executed, so it needs to be corrected by the craftsman.

So with us, the Trespa panels are screwed every 50 to 60 cm (horizontally and vertically) and do not warp one millimeter, however, ours are 8 mm thick. What I see in your pictures looks like significantly larger screw distances, are they even screwed in the middle? Normally, there should be absolutely no denting right at the screw, the panels are rock solid.

Trespa is not the only manufacturer, even if it is another one (Resopal or similar), they all have exact installation instructions and various alternative fastening options (to prevent rattling). It is simply poorly executed, so the craftsman needs to make corrections.

We are indeed relying on corrections here. Last night our contractor suggested a "discussion" between him, the roofer, and us – but we see little point in that, as it is obvious to us that there is a defective performance. We have therefore now commissioned the contractor to clarify this with his subcontractor and ensure a correction.