A few years ago I tried round tree limbs, 2x4’s flat, and 2x4’s on edge. The chickens didn’t seem to care which I used. I wound up with tree limbs for my main roosts, thanks to an ice storm when I was outfitting my coop plenty of tree limbs were available. I also have a juvenile roost that is a 2x4 on edge. Works for me. I notice that when the chickens hunker down on the roosts and fluff up in winter their toes disappear in their feathers on the tree limbs or on that 2x4 on edge. I’ve had a few winters with the coldest temperature around -4 F. Never had frostbitten feet.
I’m not one of them, but many people on this forum are convinced your chickens will get frostbitten feet if you don’t use a 2x4 flat. 2x4’s flat work, the chickens will use them. There is nothing wrong with going that way. If you use lumber, I suggest you sand the edges off so they are round. That’s mainly to avoid splinters.
And use wood for roosts. Metal or plastic transmit heat too easily. Those can lead to frostbitten toes. Using wood is more important than what shape it is in.
