
I would consult with the manufacturer of the roofing to see if they will support this application. I do not believe that most manufacturers will agree to it but that will be the critical thing to ensure warranty coverage, etc.
I'm building a 16x20 storage shed with a gambrel style roof. My plans are to put U-panel metal roofing on it. I want to stay as light weight as possible. Since the shed is 20 foot long I was thinking about buying my sheets 21 foot with 6 inch over hang on both ends. My trusses are on 18 in centers. I didn't want to put decking on the trusses just lay the u-panel lengthways of the shed. Drape the first sheet over the peak and work my way down each side. By draping the center sheet over the peak I would eliminate the need for a ridge row. I've never built a shed like this or worked with metal roofing hence me writing this forum. Will this work?
I'm not worried about warranty coverage. I'm just curious if running the sheets of roofing lengthways will provide stability on the trusses without decking.