Field problem
Verify first
Verify before you commit. Cheap to catch now.
Treat supports as load-path work: hanger installed through wrong structural element.
Verify the approved attachment point before drilling or hanging. A hanger in the wrong structural element can create a bigger problem than the duct support.
In Hanger Systems, Rods, Straps, Trapeze & Anchors, I'm looking at: Hanger installed through wrong structural element. What should I verify before I cut, drill, seal, cover, move, or install?