Heavy duct is sagging because hangers are spaced too far apart
Sagging heavy duct means the support layout is not controlling the load. Add or revise supports per the approved hanger schedule before joints deform or the run gets covered.
Do not stretch hanger spacing to save time on heavy duct or rated/smoke-control systems.
Check
Identify duct type, size, gauge/weight, liner, fire/smoke rating, and pressure class if known.
Measure support spacing and note where the joints or panels dip.
Check whether added loads, insulation, or other trades are affecting the support system.
Compare against the approved hanger/support detail.
Add/adjust supports only under foreman-approved layout.
Steps
Identify duct type, size, gauge/weight, liner, fire/smoke rating, and pressure class if known.
Measure support spacing and note where the joints or panels dip.
Check whether added loads, insulation, or other trades are affecting the support system.
Compare against the approved hanger/support detail.
Add/adjust supports only under foreman-approved layout.
Say this to your foreman
This heavy duct run is dipping between hangers at [location]. I measured the support spacing and checked the support detail. Do you want intermediate trapezes added and the run re-leveled before we seal/cover it?