First post for me. I've been a long time lurker and am going to jump into my first timber frame this summer (28x30 shed/barn). I'm getting the plans together for the county currently. I've been calculating my loads and using the beam span calculators on this forum - what a great resource.

What I'm trying to find is a rafter span chart for sizes bigger than 2x6, 2x8, 2x10 etc. I can't find any information for a 4x6 for example or a 4x8. I'm milling all my own lumber so I can make the rafters any size.

The roof I'm working on is a 12 foot span with a 65 lb snow load and 10 lb dead load. Our county here in Colorado doesn't have any adjustment factors for roof pitch or snow load duration - they plan all rafters as a flat roof.

I calculated that a 2x12 every 24" OC would work, but I'm wondering what other possibilities would work that were larger than 2x?

Thanks!