I built this roost a couple years ago, and I am quite proud of the results!
I'm not a wood worker, or a carpenter. Just a chicken owner who did something right! I referenced Building Chicken Coops: Storey Country Wisdom Bulletin A-224 for measurements.
My chicken coop isn't very big. It is actually a re-purposed storage shed. It's about 12 ft by 8 ft, with a completely wired in and roofed yard of about 8 by 8. Red tail hawks are prevalent in this area, and I'm sure they would love to add chicken to their diet.
Don't mind the holes in the back side of the shed, I raised two boys and a tom girl, they had bows, and that side of the shed faces away from the house...
I will eventually replace the ply wood, but for now I figure it offers some ventilation.
5 - 1 x 1 x 8
3 - 4 x 4 x 8
18 - 2" Nails
I then marked where each 1 x 1 cut out would go, at 17" apart and notched them at an angle so the 1 x 1s would sit flat when the roost was laid against the wall. I couldn't tell you the angles, I am pretty sure I just got lucky in that everything fit and was level when it was done.
I put this together before I put it in the coop, but you can do it either way, I'm sure.
I took two 1 x 1, and marked where the 2 x 4s needed to be placed, then nailed one in the top notch, the other at the bottom, then nailed the other three in place.
After I got it in the coop, I put nails at the foot of all three 4 x 4s, to keep it from sliding out. I didn't nail it down to the floor, so that I can move it when I need to clean up under it. It is not attached at the top.
Although at this time, I only have 7 birds, in the future when I decide to expand, I will have enough roost room for about 40 birds.