A Truss Designer’s Opinion on Bracing – Part II
When I entered the industry and was trained on truss design, I was not taught anything about lateral bracing. I didn’t even know what it was, to look for, or why to look. As I learned more, and visited job sites I began to realize the importance of lateral bracing in my truss designs.
It wasn’t until after I had been production manager and went back to designing that I was trained properly in bracing. At that point we had a new design manager, someone who wanted to teach me the right way to do things.
In Colorado (where I first learned to design), it was nearly impossible to design trusses without lateral bracing. We made a point of lining webs up in runs of trusses. We even did this in hipped roofs when possible. We would do our best to only have one brace per web.
There were times when we had no choice but to have a brace on one truss, with no webs around to brace to. In these instances we provided customers with MiTek’s T-Brace and L-Brace drawings. I even found the old diagram that we had, it is hand drawn, and dated 8-21-2002 (above) from MiTek. Industry standards require that bracing be applied on 3 or more trusses when bracing laterally. They also require you to restrain that connection at 20′ intervals. When you cannot brace 3 trusses, you can use a T-Brace. The brace must be 80% of the web, and be nailed with 10d nails at 6″ o.c. Click here for the current industry standard on permanent bracing, the BCSI-B3 from the SBCA.
In my career in the building component industry, I have seen far too many framers not properly brace trusses as they were installing trusses. I am not an expert on bracing trusses at time of installation, but I can tell you that there is a reason for doing it properly. Many framers do not read the paperwork delivered with the truss package. They are totally unaware that there are in fact 2 types of bracing: Temporary AND Permanent. I have been on two job sites where the wind has blown over all of the trusses. Both times, the trusses were demolished. The framer ended up having to buy two new sets of trusses.
So please, refer to the documentation that came with your truss pack. Trusses collapsing over are extremely dangerous and have taken lives. Sometimes ignorance is NOT bliss.
You can read Part 1 of this series here.
Stay tuned for Part 3 in this series.
Tyler Martinez – Project Manager
Gould Design, Inc.