Metal roofing lessons: day 1 on the bench: reverse seams

The first seam we learned together on the bench is one I have named a “reverse” seam. This is because the upstand part is seamed while the piece is still flat. This allows for roof gutter spouts, skylight corners, and low profile filets intersecting outside corners of any type. we used the front of a chimney apron as a model for the lesson.