Thanks for the response guys. The 3x6 is required to meet fire code regs because, I assume, it's a commercial spot. Don't know if it's required for residential. The 4x12 rafters are 4'O.C. so there will be some mid span butting, allowed provided there is two continuous runs between butts. 6:12 pitch. I'm trying hard to farm this job out. Any takers? Cash on the barrel.
What do those GRKs run you Brad?