Fence Brackets work great for installing 2x4 roosts. I purchased them from Lowes for 0.67 apiece (they are called USP 2-in x 4-in Fence Bracket). I mounted the Fence Brackets on 2x6 boards, which provided the vertical side supports for the roost bars. The Fence Brackets can be installed either vertically or horizontally, allowing you to have either the narrow or flat side of a 2x4 facing up. Each Fence Bracket is held in place by 2 screws. It's really nice to be able to slide the 2x4 roost bars out of the Fence Brackets for cleaning. I started by using 2x4 Joist Hangers rather than Fence Brackets but the hens did NOT like them as a substantial amount of metal from the joist hanger (approx. 2-3 inches) overlaps the roost bar when the roost bar is mounted to have the wide side of the 2x4 facing up. The hens did not like standing on this overlapping metal - probably because it was cold and had a relatively sharp edge. I ended up having to remove all of the joist hangers and replace them with fence brackets, which only have a small amount of metal overlapping the roost bar (approx. 1/2 inch).