A built up roof for example will typically include the built up membrane itself with or without gravel as well as some kind of insulation and cover board which will vary in thickness from roof to roof.
Roof insulation weight psf.
Asce states that rigid roof insulation weighs 1 5 psf per inch of thickness whereas polyiso insulation like thermax is 0 25psf per inch.
Thickness 12 0 gypsum fill per 1 in.
Thickness 2 5 floors and floor finishes asphalt mastic per 1 in.
Thickness 3 4 10 0 concrete fill per 1 in.
3 ply ready roofing 1 0psf 2 15 lb 1 90lb 1 7psf 3 15 lb 1 90lb 2 2psf 3 ply gravel 5 6psf 4 ply gravel 6 0psf 5 ply gravel 6 5psf.
Thickness 12 0 ceramic or quarry tile in.
Thickness 5 0 lumber sheathing per 1 in.
Weight psf sheathing plywood per in.