My coop is about 4' high. All of my girls (except my silkies) roost in the rafters which are 2x4s- 2" side up. They seem to have no problem balancing or getting up there as I have different branches (intended for them to roost on) at different levels providing a "ladder". I have read that the square 2" side isn't the best, but it's what they prefer. Any suggestions?