Recently while traveling, I photographed a load of structural components being delivered to a jobsite. It was a little of a double-take to comprehend what was on the truck, because our products really shouldn’t be that curved when they’re designed to be flat. As shown in the photo [See PDF or View in Full Issue], that I-Joist near the top of the load now is distorted to the point that its structural integrity is in question. Although I’d like to give the loader credit for securing his load, the methods he used have failed to consider the weaknesses of the product and the potential damage his actions have caused.
The next photo [See PDF or View in Full Issue] is an order of trusses being loading onto a roll-off. A note has been added showing a location where blocking is recommended. The problem is that the orange loading strap can be tightened to the extent that it can flex the trusses above. This can distort the truss by side-loading the bundle, and can cause extensive forces in the connections which can damage the fibers in the lumber. This type of damage is exceedingly difficult to detect, so it must be avoided before the load ships out. By adding the blocking, the load strap can be tightened significantly without distorting the trusses.
The third photo [See PDF or View in Full Issue] shows a very well stacked load that uses the trusses in a pattern that eliminates potential distortion as the load is bound. An improvement would be to add blocking at the arrows where the third group of trusses from the bottom occurs. This situation happens when vaults and scissors are intermixed with common trusses. The blocking would provide a more secure load and would eliminate any potential distortion.
Structurally, the most difficult part of a truss’s life is making it from the finish roller to the roof. Proper banding keeps your product in top form and helps you provide the structural performance your design dictates. It is an especially important step; and if neglected, it can be an exceedingly difficult issue to evaluate—that is, until there is a field matter, and then it’s too late to remedy without costly replacements or repairs.
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.