Hanging rafters from an interior wall

[InfiniteArts]

design challenge.pdfNew User here.  First, thanks for looking at this, and helping me out.

I cannot for the life of me figure out how to design this in Chief Architect. 

Goal- Attach rafters to a ledger board on an interior wall. 
Details- Building is 45' across, 44' deep.  Divided in three main sections, 14' 6" wide (44' long).
Exterior walls, on wing sections= 8'.  Rafters climb 4/12 over 15'.  Attach to an interior wall 13' above floor.  Center section would carry 4/12 common trusses (no tails).

Progress- got the two wing sections to build properly, cannot get center roof plane to act accordingly.  Every time I add the center roof plane, it does a weird shed roof, from front to back.

Solutions I've thought of-
Having the interior walls be "exterior walls", with changed material make up, but I can't seam to figure out how to create different wall profiles in the same drawing.
I discovered roof groups, which allowed me to make some forward progress, but that isn't even technically right, as the two shed roofs sit on top on the interior walls, not hanging from them.
Creating three separate buildings and butting them up next to one another, but that creates an extra thick interior wall, so, no.

I have included my best attempt so far, and also a PDF front section of what I'm looking for.

Any ideas?

Thanks again,
Jon

Oregon house 2A roof test almost.plan