U panel on a Gambrel Roof

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?