What Decisions Should Truss Builders Be Able to Make?

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Issue #11237 - April 2019 | Page #34
By Glenn Traylor

In the November 2017 article, “So Who Exactly is Responsible for Lumber Quality?”, we discuss the abundance of quality building materials and the responsibility of the fabricator to evaluate their application in products. We should recall the ultimate decision maker in determining what gets used in the truss is the component manufacturer.

So, what are some of the issues our truss builders should be able to identify? The most common defect issue is wane. Wane can exist within grade, so wane alone does not rule out the use of a piece of lumber. Wane becomes a problem when it is in the plated area or impacts the application of sheathing materials. In the first photo [see PDF or View in Full Issue], the diagonal web member has extreme wane which prevents proper embedment of the connector. This web should not have been used in this application. While it might have met grade, it is not suitable for this truss.

The second example of a defect is a mill cut. This type of cut can be missed by the graders. It may look insignificant, but the cut creates a stress concentration in the member. This piece of lumber should not be used in trusses because it is compromised.

The third photo is another example of wane, but in this case the lumber could have been used if the wane had been taken into account during the building process. This lumber could be in this location if the builder had upsized the connector and repositioned it to provide sufficient tooth holding in the chord.

Great fabricators empower their workers to make solid decisions on the fly using sound judgment and carefully defined rules. Truss builders should be able to make these assessments and act on them—can yours?

 

Glenn Traylor is an independent consultant with almost four decades of experience in the structural building components industry. While he is a TPI 3rd Party In-Plant Quality Assurance Authorized Agent covering the Southeastern United States and performs 3rd party safety auditor services, these articles represent his personal views, knowledge, and experience. 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.

Glenn Traylor

Author: Glenn Traylor

Structural Building Components Industry Consultant

You're reading an article from the April 2019 issue.

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