The past twenty years have brought many changes to the Metal Plate Connected Wood Truss Industry. These changes require manufacturing to change too, as the entire process continues to evolve and mature. Here is one situation where changes in manufacturing are necessary.
Not too long ago, component manufacturers were required to maintain lumber stamps and markings throughout the manufacturing process to provide validation that the lumber they were using met design requirements. Back in the day, fabricators would purchase specific lengths from lumber manufacturers in increments that made sense for their operation with this need in mind. This lumber would be cut on component saws and the boards were designed to maintain their grade stamps.
Importantly, the component manufacturer (CM) has been allowed to crosscut lumber without impacting the lumber grade if the lumber was marked as that grade. (A “marking” exception can be short lumber, but that’s another article.)
Examination of the process
Today, with the advent of linear cutting, maintaining a lumber stamp is impractical if not virtually impossible. While this might be a disadvantage to grade traceability, the value the linear saw brings regarding higher yield and reduced labor makes the new problem worth the extra work.
To maintain compliance with the ANSI/TPI 1 standards, lumber must be selected that meets or exceeds all eight properties that define the grade. (For more on this topic, see my December 2021 article, “Can I Substitute Lumber of Another Grade or Species?”) When weekly in-house inspections are made, inspectors should verify lumber grades.
When 3rd party inspectors review the CM, this process should be repeated. So, with all the cutting up of lumber and the fact that lumber manufacturers normally stamp their products in one place, what should the CMs be doing to provide traceability of the lumber? How can CMs maintain the lumber’s pedigree? The following procedures and processes can be implemented in part or in total to help ensure compliance.
Receiving Lumber
1. When receiving lumber, transfer grade indicators by painting the end of lumber in the unit. Some lumber manufacturers already do this with a stamp. Caution, sometimes the wrong piece gets bundled with another grade at the lumber manufacturer, so be sure to watch for this situation.
2. Segregate lumber species and grades, and keep them segregated when storing lumber.
3. Limit the number of lumber grades inventoried at the plant.
4. For the typical CM, consider stocking limited grades of wide lumber. This would not be practical for high snow load regions or agricultural trusses.
5. Document your receiving process and keep records.
Processing Lumber
6. When rejecting lumber or reclaiming drops at the saw, make sure to segregate and tag unmarked lumber using your plant’s marking system or a manual process.
7. Although the linear saw’s batch program is very reliable, verify its process on occasion, at least monthly.
8. Mark process lumber with wax markers, using different colors for different lumber grades when grades become mixed (usually during the picking process).
9. Use the linear saw’s printing capabilities to mark components. A batch number printed on the cut material can provide an investigator the link to follow.
10. Be familiar with lumber grade requirements so problems can be spotted.
11. Document your lumber process and keep records.
The Bottom Line
The changes in cutting processes dictate a different approach to lumber traceability. In the old days, following grade marks worked well. Today, establishing a precise process is much more effective and provides the “paper trail” for audit. This process should be documented in your quality assurance program manual (QAP) and will become a review element during your 3rd party audit.
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.