The roof structure rises by almost 2 cm upwards!

Deletion, as too late.

... because the OSB boards expanded and since they are screwed in, they pushed the entire roof structure upwards ...

That was the original post and I used this statement as a basis. If this fact is not correct, then the entire discussion here is just guesswork. The question was whether the OSB boards can lift the roof structure, and my clear answer is no.

That was the initial post and I used this statement as the basis. If this fact is not true, then the whole discussion here is just guesswork. The question was whether the OSB boards can lift the roof truss, and my clear answer is no.

Sorry for only getting back to you now; normally I always get an email when someone replies. You are right, that is the main question. I spoke with the site manager again yesterday; he would do it for 700 euros because the OSB boards are to blame... and as I said, lift the entire roof structure upwards... He and his employees or colleagues are the only ones who see it that way... I will probably need an expert... because two weeks ago he said that if I loosen all the screws upstairs, it will settle down by itself again, but now he says that doesn't necessarily have to be the case. I really think they are just guessing what might be there, that's how it seems to me... :-(