Roof systems in homes basically fall into two categories: stick frame and manufactured trusses. By far the majority of homes today are built with manufactured trusses. However, 75-years ago most homes were stick framed. Stick framed houses could be very good or very bad depending upon the knowledge and experience of the carpenter. I have seen homes in Spokane with 2x4 rafters spanning 15 feet and was amazed that the roof did not collapse (a 2x10 @ 16” on-center would be correct size). On the other hand, manufactured trusses are specifically engineered for roof loads.
In our early years my Dad showed Tom (my brother) and I how to build our own roof trusses. This was time consuming and did not have any ‘certified engineered’ design.
Once in a while we still build a timber truss or two for projects, which is fun. On this project, we are making trusses from glue lam beams and metal gusset and bolts. We cut the parts on the ground and test that everything fits correctly then haul it up to the roof and assemble in place. What a fun job!