Mine are 30" and I haven't had a problem, but there are definitely heavier birds around than mine. I have some Australorps but they are hatchery quality and really not as big as the breed gets. It also depends on the amount of space they hav available to fly down from the roost. Mine is a large coop with about 8' of space from the front roost to the wall, so they can flap a few times on the way down. If they had to jump straight down, it might be a little rougher on them.
Sorry, I don't have any definite numbers to give you.
Sorry, I don't have any definite numbers to give you.
