Hi. guys and hope you are all doing well.
Back in the 1970’s, people (contractors) started simulating roof trusses that were coming out as Engineered Trusses. Since the factories were few and far between, older Carpenters caught on to the fact that Engineered Trusses were faster and more economical. They proceeded to improvise the steel connector plates with plywood 5/8" thick for gusset plates and chose to stay with the oversized lumber they were using as was normally used for stick building. Therefore, you actually ended up with an over Engineered Truss Manufactured by our Fathers of Time.
The plywood gussets were about two feet long for a 4 in 12 pitch at the overhang and three feet to four feet long on the plumb cut , depending on the estimated load, sometimes that was applied on both sides.
The Monoplaner trusses at the time would have had the first chord point at roughly 10’-11" for 2"x4"bottom chord. the angel of the fink chords were 12" rise to 3x the run. This was the basis of the home built truss design.
Since Northern Maine as well as our Canadians friends have a good shore of snow load, most rafters and ceiling joist are almost always 2"x6" wether or not they are stick built simulation of a truss or not. More are using the Engineered Truss now that is manufactured with 2"x4" because of the Engineering behind it for the dead and live loads.
Looking at my Architectural Graphic Standards book Sixth Edition, with a Copyright of 1970, I guess it would be time to renew. ha. ha. Changing just takes me awhile guys, so bear with me. LOL.