How the product will be used is a very important consideration when designing components, and it also comes into play during fabrication.
The attic trusses in the photograph have a wedge installed at the wall–ceiling intersection. This is the intended design. Deeper in the rack, however, the same connection omits the wedge. Identifying this manufacturing error brings to light an opportunity to reflect on end use considerations.
In the case of an attic frame, given the deliberate open design, chances are the owner and/or builder will want to utilize the full room, including a square corner, in order to give the room clean lines and full clearance. It is possible that the designer used the wedge to force the joint to plate due to software analysis. If the component is manufactured with plates extending into the room area, chances are extremely high that the plate will be cut out, removed, folded over, or otherwise damaged in preparation for the drywall installation. Often this work is not done by the framer, its other trades, or non-skilled labor performing the work.
The rendering by Gould Design Inc. illustrates an excellent design that takes these factors into consideration. Plating is kept out of the room area, preventing the conflicts. Field modifications will not be necessary, eliminating the need for field engineering and analysis.
Although the truss assemblers are not responsible for the design, understanding all of the dynamics at play can definitely help avoid unintended consequences!
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.