We are ready to put roosts in our chicken house and my husband is insisting that he is just going to screw in the 2x4 (4" for them to set on) into the studs of the house. He thinks that will be far enough away from the wall. I told him they need more room than that for their butt and tail feathers to stick out behind the wood. He is not listening to me, so has agreed to let me ask you guys of how far away from the wall should the roosts be? Thanks for your help.