Should I caulk or pain the 1/8" gap between 3/8" masonite and a vertical corner or window trim?

Question

I keep getting moisture problems. I think it may be trapped moisture that is not draining. I caulked it and that does not seem to help. Bad boards maybe? I think I will replace the masonite in these areas. Just want to take care of the slack in a proper way. Thanks.

Answer 1

calk it, use one that will move as the material moves, [stays flexable]