Do you vertically stack your trusses or horizontally stack them? How does the method impact quality? How does it impact safety? Do you know the arguments for either preference? Almost as if it was a regional inclination, some areas of the US vertically stack their finished trusses and some areas horizontally stack their finished product. Let’s look at the positives and negatives of each.
Vertical Stacking
Pro: Trusses generally self align when stacking common trusses and some vaults.
Pro: Each truss can be inspected completely by the truss stacker, because the full view of each side is available.
Pro: Trusses can be stacked manually on racks or automated stackers can be used.
Pro: Vertically stacked trusses take up less space.
Con: Trusses can be blown over by the wind if not held in place.
Con: Trusses can be harder to band together and require man lifts, steps, or other safe means to access the point of banding.
Con: Odd trusses sometimes do not align very well, especially configurations such as dog leg and double vaults.
Horizontal Stacking
Pro: Trusses are easier to band together on the ground and don’t require special equipment to gain safe access.
Pro: Wind is not an issue.
Pro: Trusses can be stacked manually on racks or automated stackers can be used.
Pro: Trusses must be aligned by sliding truss over truss. Often trusses below are tacked together to prevent movement when dragging another truss overtop.
Pro: Virtually any stacking configuration is possible.
Con: Each truss must be lifted prior to stacking in order to inspect the back side of the truss.
Con: Horizontally stacked trusses can take up much more space.
This photo [see PDF or View in Full Issue] is a larger view of the stacked trusses above. Note the arrow points to the location where the trusses are tied to prevent being blown over. This location by itself may not be adequate to prevent a dangerous situation from occurring.
Weighing the pros and cons, vertical stacking makes quality inspections easier, but dealing with elevations can present safety issues. For each negative, some action must be taken to remedy the issue. If the plant is horizontally stacking and is not lifting each truss for a complete inspection, trusses may be leaving the plant with serious manufacturing defects that can create increased risk. Both sides of the truss need to be looked at 100% of the time regardless of the stacking method. In the end, using a combination of the two methods may offer the best of both worlds: vertically stack the trusses that work best vertically and horizontally stack the rest.
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.