Static field route #19324

What do I do when a wide trapeze strut bows under the duct?

Hanger Systems, Rods, Straps, Trapeze & Anchors⚠️ CHECK BEFORE YOU FIXField answer expansion

📖 Verified core answer

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.

Open in Field Rescue Open category

Field verification checklist

Measure how much the strut is deflecting.
Check whether duct corners are being pinched.
Confirm rod spacing and support detail.
Unload or temporarily support before swapping strut.
Re-level after upgraded support is installed.

Ask foreman

The trapeze under [duct/run] is bowing at [location]. I checked the span and duct skin. Do you want a heavier/deeper strut or center rod added before we keep loading the run?

Text to foreman

Route options

AMake the field correction only if it is within your assignment and the approved method.

BHold and document the condition if the fix affects support load path, structural steel, seismic restraint, life safety, another trade, or inspection.

CBring the foreman/detailer the location, what you checked, and what decision you need before loading, cover, startup, or rework.

Do not do this

Do not keep stacking duct on a support that is already sagging.

Why this matters

Support deflection can distort duct, open joints, create air leaks, and weaken the hanger system.

Final verification

Use this as field training guidance. Final direction still comes from the foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, structural/seismic detail, and AHJ/code requirements.

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