TinnerFlow™2nd YearTrapeze / Span DeflectionYELLOW · Check First
A bowed trapeze means the support span is not stiff enough for the load. Upgrade the support or add approved intermediate support before it distorts the duct.
Wide duct on light strut can turn the trapeze into a sagging cradle. When the strut bows, the duct corners and bottom skin can distort.
Check span, duct size/weight, rod locations, and clearance. The usual recovery is heavier/deeper strut, back-to-back channel, shorter spans, a center rod, or a separate engineered support.
Do not keep stacking duct on a support that is already sagging.
Support deflection can distort duct, open joints, create air leaks, and weaken the hanger system.
Final direction still comes from approved drawings, specs, manufacturer instructions, employer policy, foreman/detailer direction, structural/seismic details, and AHJ/code requirements.