I have a few chickens that like the 4" side of a 2x4 and a few that prefer a 2x2. The 2x2 crowd roost on the supports for the 2x4 chickens are fickle things!
I've got 2x4's wide side up in one coop and opposite in two other coops. My larger breeds (and older ones) just look awkward when they are trying to position themselves on the skinny side up. Not saying I'm going to run out and change them, but I'll keep wide side up from now on! I liked the 2" side up so I could use joist hangers for easy removal, though! That's super handy
Feel free to check out the links below for some interesting reading. Good luck on your adventures!
Hello Crystaluna13.
Welcome to BYC.
My opinion and the opinion of the chickens up the trees here is they prefer a branch they can curl their toes around.
Nature doesn't do flat branches really.