I'm currently working on refurbishing a slant roof dog house (turning it into a coop) that is 3' wide by just a little under 4'6" long. The roof is currently shingled, however, some of the shingles are brittle and there's one spot where the shingles have broken away and the wood is exposed. In lieu of re-shingling, I'd like to just place a corrugated asphalt roofing panel over top of the existing shingles (which, according to the specific product I'm looking at, one can do this). The panels come 4' wide by a little over 6' long. I'm obviously going to have to cut the length, but, I'd like a little bit of an overhang on the sides, front and back. Would a 6" overhang on either side of the coop be too much? Too susceptible to the wind catching it and ripping it off? Thanks!