I had some low hanging roof pieces that I was afraid the kids would get hurt on by cutting a corner too closely. So I built "Chicken Coop Bumpers" out of a steel T-post, swim noodle and PVC pipe:
https://www.backyardchickens.com/threads/great-idea-ruined-by-vast-pvc-conspiracy.1476489/
When I build my coop, I considered something like this:
Peel & Seal Self Stick Roll Roofing (for RVs)
https://www.amazon.com/MFM-Peel-Stick-Roofing-36in/dp/B000HE7RYQ/?th=1
I ended up going with metal roofing. They really aren't all that difficult for newbies like us ... and they pretty much...