Structurally your options include putting the roof panels just over a framing system.
How to cover circle roof with metal panels.
If you segment the roof into a bunch of pie shapes though you can use other panels as well.
You do have some options in metal though.
To make a truly round roof in metal you need eitehr tapered panels or some of the metal panels will work.
In this video i cover measuring the roof figuring the metal th.
Whether installing metal panels on walls ceilings or as a roof the process is the same.
This is part 1 of a 6 part video series explaining how i installed a metal roof on my house.
Panels can be installed directly to studs or on top of an existing sub surface such as plywood or drywall.
If there are gutters installed on the eaves the eave flashing should be installed to overhang the lip of the gutter by about 1 2 inch.
Corrugated roofing sheets are an inexpensive way to cover a patio shed or greenhouse and are available in colors such as white blue and green as well as opaque colors and clear plastic.
My main tool for perfection.
Install metal panels with ease.
Use 1 1 4 inch nails to cover the outline of the roof with strips of metal eave flashing also called edging.