I am trying to draw a simple truss for a storage shed that is as close as possible to the stamped drawing I have from an engineer. The outside wall edge to wall edge distance is 10 and the roof overhang is 1'. There is a single bottom chord (collar) that is 4' long at the bottom of the chord, that ends up being 1' above the top plate - pitch of 4 in 12 no birdsmouth. I have home designer pro so I think I could do this at least two different ways and I have tried both.
1a) Build the wall, ceiling, and roof to set the top plate height and the roof baseline
1b) Set the room ceiling height one foot higher so that it is at the bottom of the truss chord (sloped ceilings seem to automatically follow the bottom of the roof plane minus the framing height (3.5")
1c) Draw Trusses
2a) Use two sloped ceiling planes and either the existing ceiling or a third sloped ceiling plane that is set for a pitch of 0 for the center 4' of the ceiling. When I do that I put the sloped ceiling (roof baseline that is one side of the ceiling plane) baseline on the outside edge of the wall and specify the outside bottom height to be at the top of the plate with a pitch of 4. Maybe I should be putting the ceiling baseline on the inside of the wall?
The point is I have tried a bunch of different ways to do this with varying results, no of which are what I want. I think there is something wrong with my design on the right side of the roof ridge that is causing problems. In the attached plan, I can't place a truss on the right side of the roof at all because CA doesn't think there is a roof plane there. I realize that I need both a roof and ceiling plane. This is a different error than the one saying that there is not enough room between the roof and ceiling planes to place the truss - I've seen that too.
Previously, I was able to draw a truss across the whole roof and it looked good except that there was an excursion down to the top plate (default room ceiling height) even though I had a sloped ceiling plane over it.
I have been looking for the difference between the left and right side of the roof and framing but I haven’t found it. In the attached plan a lot of things have been deleted and then manually redrawn to try to narrow down what the issue is but with a fresh rebuild of the roof, etc. I had the same problem.
It seems to me that there is a roof and ceiling plane and there is enough room between them for the truss
Any help would be greatly appreciated