Originally Posted by bruceisla
Another possibility, depending on whether you have trim over the seam, is that you are seeing rust. Sometimes water can get behind the trim or thru a screw hole and the screw itself is rusting.
Thanks for your reply. Currently I have not ruled any possibilities out. I swept the roof off yesterday and continued inspection.
When I open the bay door after a rain there is water on the back side of the door. It's not getting in the bay itself. I have caulked around anything including windows that I thought it could be coming from but no luck yet.
Once again thanks