all manufactured homes today have to be made under hud standards i assume this was a factory metal roof call the hud office in texas and someone there will be able to tell you what the fasteners length is also the atterny generals office has a office on manufactured homes for some reason. but you might have a case against the manufacture on this. zone 1 covers 90 % of the country.

Man, what a defect. Do you actually mean the metal came off or was other parts of the roof involved, like the rafters, OSB and such? How old is your home? That really don't matter, but just curious?
I know someone you can talk to about that. Most posts here are questionable?