Thickness 3 4 10 0 concrete fill per 1 in.
Roof insulation weight psf.
Thickness 2 5 floors and floor finishes asphalt mastic per 1 in.
Thickness 12 0 gypsum fill per 1 in.
Thickness 1 8 0 4 gypsum sheathing per 1 in.
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.
When it comes to estimating the weight of an existing roof field verification of the in place construction is necessary.
Thickness 12 0 ceramic or quarry tile in.
Weight psf sheathing plywood per in.
Thickness 5 0 lumber sheathing per 1 in.