Face the facts—occasionally, it is necessary to replace connectors. It’s part of the manufacturing process. In my May 2016 article, Is There a Reduction For Plating in a Previously Plated Area?, we discuss the limitations and considerations of removing a plate, including upsizing the plate and how to calculate the necessary upsize connector. The area of the chord and web members where holes have been made by the original plate loses 50% of its capacity, so the replacement must be done with a larger plate. Typically, smaller plates can be replaced by upsizing the connector by height and width up one size, but as the plate size increases the proportion must increase.
Witnessing a truss repair recently, I noticed a truss builder aggressively removing a connector. Although I had thought this was intuitive, it needs to be said aloud—special care must be taken when removing a plate. After removing the plate, this truss builder was planning to just replace the plate with a slightly upsized connector, but I asked him to wait until we could investigate the repair. Unfortunately, a significant amount of wood had been removed, which created a significant problem. The area that was damaged by the wood removal had become totally ineffective. That meant additional tooth count would be required in the damaged area. Bringing this to the attention of the builder and his supervisor, I realized this calculation surprised them. Per ANSI/TPI 1 section 3.9.2, when a plate is removed, the area of removed lumber becomes ineffective.
As shown in these photos, a significant amount of wood may be destroyed while removing the connector. [For photos, See PDF or View in Full Issue.] This area must be replaced 100% by upsizing the connector accordingly.
The diagram shows how either the 50% requirement or the 100% requirement will be activated after you remove a connector. [For diagram, See PDF or View in Full Issue.]
Another requirement that may seem intuitive but also should be said aloud— remember that the upsized connector must be of the same type and gauge. That means you cannot replace a 20-gauge connector with an 18-gauge connector, for example. This also comes from ANSI/TPI 1, section 3.6.6.
The final statement that needs to be said aloud is this—taking a few extra seconds or minutes to “be careful” will be worth it, because you need to take special care not to remove wood when removing a connector. Not only will the damage make your repair more difficult and require a larger connector, it also may make your repair impossible.
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.