Currently I have a 100% flat roof. There is no slope at all. For roofing material I have that green corrugated PVC roofing. It has warped from sitting in the sun and now sags between the supports so water pools up there. If you follow the corrugations they run towards the door and the run (design flaws) so water just pours into the run and right in front of the door when it rains. What I would like to do is give the roof an arch /\\ How do you go about doing this? Would I just run 2x4's with 45 degree cuts so that they join in the center and then attatch my roofing material to that? It doesn't need to be hardcore up to code or anything I just want to direct water flow off the sides of the coop. Any ideas?