Similar idea as prefab homes.

immihunk, not sure what you mean by "strong enough to guarded". Are you looking to do a roof top garden? What is your objection to wood decking? It is strong, lightweight and will make a fine deck surface that allows drainage. We've don a few with removable panel systems for cleaning and maintenance. I'll monitor this discussion and maybe you can fill me in?

lookup Grenfell Tower fire in London. Few months back this tower caught fire. The reason for such a tragedy was that in a bid to improve the looks of the old public housing building they clad it with PVC backed aluminum cladding. The building was otherwise designed to contain accidental fires but adding the cladding caused the flames to spread from outside the building. PVC also gives off minute amounts of hazardous gas. Using it in such large indoor surfaces exposes you to potential fire hazard as well as health hazard.

pls share your existing building photographs.