My trainer has a metal roof over it that is attached to an electric winch. The winch opens the roof; it is hinged along the back. Really cool.
I spent an hour at Lowes with a man who really knows what he is talking about.
He said that I should make a basic frame and then use 1/4" plywood (the stringy fiberboard kind for outside use). It will be easy to screw the metal on top of that.
Problem is that my bin is 10 x 12 and plywood is 4 x 8. So I need a left and right side with overlap in the middle. This creates 2x 5’ x 12’ sides. If I run the metal the long way, I will have a lot of seams, so he suggested I run the metal sideways and then I will only have 1 seam on each side.
The center front will have a (removable) 6 x 6 post with a bracket on to and the center back will have a bracket on the existing post. Then a 12’ 2 x 4 or 2 x 6’ will span the two, so the sides have support when in the down position.
There are still details to be worked out (the bin slopes toward the front – do I raise it up to be level or have the roof slope, even as the water is running off on the sides?)
Right now it is freezing cold and so nothing will get done this week, but in a week or two construction of the roof will start. I will take pictures as we go, so others can decide if they want to do a similar project.