I appreciate all the answers I got from you.
I will follow your hints with the plywood. Can't wait to see the trailer and check for the damage.....three more days left....
When I'm there all the necessary will be done to get it fixed "the right way" - and also the rest of the roof will be maintained.
Trailer is in storage through the year when we are not there...this is a long time and I need to safe that everything is dry and no other leak occurs when we are in germany. After we leave now in sept. it will take to march before we come back......