calculation for a lean to

Kobelco February 14th 2020, 10:35 pm

I need a little help with load calculation for a lean to replacement on a barn. For the rafters I plan to use 2x8 x 26' white pine better than #2. The first support post (6x6) will be 17' from the barn I can not put it or another closer. Lean to will be 16' wide w one post on each side. Tin roof 26 gauge. I don't know pitch yet probably more horizontal. What spacing for the rafters? I don't want it to heavy. Atlanta Georgia area.
Thanks,,,,