Truss Design
Question:
Recently, I was invited to view a newly-constructed 60 ft. by 36 ft. barn, with homemade big timber trusses as follows: 36 ft. span, 12/9 pitch, construction was 26 ft. 2x12 rafters, bracing 2x6, ceiling joists were 36 ft. boxed, 6x12 out of overlapping (6 ft.), 2x12 glued and nailed center, 16 feet of joist doubled as an 8 ft. high loft, floor trusses were on 12 ft. centers atop posts deeply anchored with good footings, roof and wall cross ties were 2x6 on edge every 24 in., floor cross ties in the loft were 2x8 on edge every 16 in., 4 ft. snow load. My daughter and her husband now want to build this same barn, but I am concerned about the combined snow and floor loads. Is this a sound structure?
Answer:
SBCA is a trade association that represents truss manufacturers all over the country. As such, we don’t actually perform truss design and can’t give a definitive answer to your question. It sounds, though, like you are describing a type of homemade attic truss. A structural engineer in your area is the best person to determine the soundness of the structure. We suggest that, when recreating this barn, you consider using pre-engineered truss frames. Check out our Members Section for truss manufacturer listings – one of our members would be more than willing to assist you.