roof rafters - no ceiling
I'm working on a framing plan for a customer - the house has a very large 12/12 pitch roof and much of the 2nd floor is located inside of it. The living room of the house, on the plans, shows a vault from the exterior walls going flat at the same height as the 2nd floor ceiling. The longest rafter span (to a king rafter) is ~21'. There is also no way to support the ridge as it is over the living room.
End result is I can't use an i-joist rafter because there is no where to support a structural ridge, conventional framing doesn't even come close to working b/c the lack of ceiling makes the rafters way out of span. I thought about designing the top plate as a beam but can't get it connected at the ends.