Marcy Field Cot

[pony express]

A question on canvas-I have a couple of army-style cots that are in similar condition to Col Pitspitr's "blowout"cot that Delmonico pictured above. I'm planning to re-cover them, as well as some canvas "director's chairs" I have, what weight of canvas do I need to use? One period fabric site has 13.5oz Sunforger canvas, would that be heavy enough, or would it need to be heavier?