Insulating garage roof, correct sequence of execution

Where does one have 80% humidity outside at -10 degrees? And 50% inside is probably wishful thinking as well

Oops, sorry, my mistake. I was a bit too quick. The outside humidity obviously needs to go down. The one in the garage, rather not. The result shouldn’t be much better.

I’ll leave the file as it is anyway. The approach should be recognizable.
Anyone who wants to check their individual project can do so there.