TinnerFlow™2nd YearHangers / SupportsYELLOW · Check First
A bowed trapeze means the support is overloaded, undersized, or spanning too far. Do not leave the duct hanging on a deflected support; verify the load and upgrade the support method.
If a trapeze bar bows under a large duct, the duct may be physically up but the support detail is telling you it is wrong. Big double-wall duct, heavy gauge duct, lined duct, outdoor duct, or extra added loads can exceed a light support setup.
The recovery is to support the load correctly: stronger strut/channel, closer hanger spacing, additional rods, a center support, or an engineered support detail. The exact rod/channel/anchor choice should follow the approved support schedule and foreman/detailer direction.
Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.