Why suspend the chicken roost? So that you can clean under them without the legs getting in the way. In fact this is a temporary chicken house, when I build the permanent one, it will have hinged roost that can be folded up against the wall for cleaning.

This is simply 2x4 braces with closet rod used for roost. Supported to the rafters with electric fencing wire. It is very simple and fast.

Chickens all have their own desires when it comes to roost and nest. That is why you need roost at different heights. The bottom roost should be 18 to 24 inches from the floor. The rooster usually likes to be at least 5 or 6 feet from the floor. So that he can watch his harem. The roost need to be offset at least 12" so that they to not poop on each other as they roost. The roost need to be 1" to 1.5" in diameter and made from something they can hold on to, wood is the best.