I'm building a 12'X16' shed. The width is 12', so my rafter span would be 6', minus half my ridge board (3/4"). So the total span will be a little less than 6'. The roof pitch will be either 6/12 or 7/12. The rafters are going to be spaced 16" OC. I plan to use 3/8" plywood for the roof sheeting and asphalt shingles. The plans I have call for 2X4 rafters. I was just wondering will those be sufficient, or should I go with 2X6? I live in Alabama, so snow is not an issue.