Originally Posted by Roofmaster417
I guess I am a goober because on a 30sq.overlaying plywood (7/16")I just thought that 4500lbs was 4500 pounds?Feathers and bricks.
I was in a hurry when I typed that, had an emergency repair to get to, and I left my statement incomplete, you can do it per 100 square feet or individual.
You should also include the weight of fasteners, underlayments, possible weather issues such as snow if you live in a snow region, etc.
You figure the true weight, roof slope & structural design of the trusses and then determine if the added sheathing is/will be a weight bearing issue.
If you live in a home in which your roof can't handle the additional weight of a layer of 5/16" or 7/16" sheathing you should be concerned with that structure.
Ask you local county engineer about that.