Recently, when a building owner started getting leaks in the roof and noticed unusual variations in the ceiling, I was asked to do an inspection to determine the best way to correct a deflection problem. Upon inspection, it was very evident that the roof trusses had not been installed correctly and lacked the fundamental bracing necessary for the trusses to perform their task. [For all images, See PDF or View in Full Issue.] Because of the lack of top chord bracing on the base truss, the following problems were growing:
- The classic “serpentine” or “S” pattern of chords had developed (see sketch), indicating buckling was occurring on the top chord of the base truss.
- Heels of the base truss were starting to separate.
- Interior webs were starting to break and crack due to the excessive forces exerted as the trusses deflected lower and lower.
- Trusses were out of plane by as much as 6 inches.
The truss will collapse if no action is taken. Let me repeat that – the trusses will fail and the roof will come down. The problem is such that the building has been condemned and cannot be inhabited. Because of the scope of the problems and the separation of connectors, given the visible and other hidden damage, the trusses cannot be salvaged safely nor economically.
When asked by the building manager what caused the problem, I explained that it began the day the trusses were being set. Apparently, the framing contractor was not aware of the additional bracing requirements. As a result of the framing, the contractor has reduced the life span of this building significantly. Their lack of proper bracing will cost the building owner much more than the original cost of construction.
So now you are probably asking “does any of the responsibility for this problem fall onto the fabricator?”
Fabricators cannot monitor all of the projects where they provide materials, but they can provide the necessary information to help ensure their product’s proper installation. In this case, the history of these trusses and the transaction between the fabricator and client is not available to me; however, given the extremes in this situation, I feel certain that reasonable steps were not taken that would have avoided this outcome.
Key factors that should merit extra concern on a project are any of the following attributes:
- Spans of 50’ or greater
- Piggy-backed trusses
- Large over-framed areas requiring significant bracing
- Deep scissor trusses with a small pitch differential creating a high center of gravity
- Inexperienced customers
- Field-spliced trusses
- Community projects.
To help your contribution endure throughout its design life, however, you can consider taking the following steps.
- Complete a needs assessment. These discussions are helpful to disclose limitations in education and experience that might create a problem.
- Review what may be “obvious” potential problems and identify appropriate solutions.
- Consider including SBCA’s BCSI booklet on all projects with any of the key factors listed above (they cost approx. $50 each). https://pubs.sbcacomponents.com/products/building-component-safety-information-booklet
- Always provide Sealed Engineered Design, especially for projects that have a high degree of failure due to improper installation.
- Include pertinent BCSI summary sheets with all orders. Make it part of your Jobsite Package. Make it part of your shipping items documenting that you supplied this information.
- Avoid providing limited information or incomplete information on your own.
- Integrate “bracing required” tags that make the field confront the need for additional bracing. These tags are durable and remain with the truss. https://pubs.sbcacomponents.com/collections/truss-tags
- Spray paint or stamp bracing notifications on trusses at the points where bracing should be installed.
- Sell bracing members that provide the bracing membrane. These can be similar to gable ends that are designed to lay on top to brace trusses. You can also provide flat “wall panels.” These are easy to manufacture and can utilize otherwise culled materials.
Working together with your client will help ensure their project is successful and will reduce your exposure to litigation. Your efforts will help your components achieve their ultimate value. It’s a win-win strategy.
An ANSI/TPI 1 3rd Party Quality Assurance Authorized Agent covering the Southeastern United States, Glenn Traylor is an independent consultant with almost four decades of experience in the structural building components industry. Glenn serves as a trainer-evaluator-auditor covering sales, design, PM, QA, customer service, and production elements of the truss industry. He also provides project management specifically pertaining to structural building components, including on-site inspections and ANSI/TPI 1 compliance assessments. Glenn provides new plant and retrofit designs, equipment evaluations, ROI, capacity analysis, and CPM analysis.