But for now, the flooring: what I'm thinking of doing is fastening a series of pressure-treated 2x4 "joists" to the concrete deck surface and nailing the 1x6 treated wood decking. The concrete surface has a slight slope away from the house so water will not "pool" under the 2x4's, although they may remain damp for a few days after a rain. I don't know if this will be a problem, or if there is something else I could do for the "joists".
There would also need to be provision made for the posts of the deck rails and the posts for the metal roof.
Am I on the right track?