Duct resting on threaded rod or sharp support edge
Duct resting directly on threaded rod or a sharp support edge can cut into the duct skin, insulation, or vapor barrier. Correct the bearing point before the duct is fully loaded.
Ask before moving anchors, changing spacing, deleting supports, drilling structure, or altering trapeze/seismic layout.
Watch out
Do not let duct sit on threaded rod or sharp metal edges, even temporarily, once the duct is being loaded.
Check
Identify exactly where the duct is contacting the sharp edge: bottom corner, side, or full bottom face.
For duct against threaded rod, use the approved cushion, isolator, sleeve, saddle, or support detail before the duct carries load.
For duct on a sharp strut or metal edge, use the approved edge protection, saddle, bearing pad, or support correction required by the job.
For insulated duct, check whether the insulation or vapor barrier is already compressed or torn at the contact point.
Do not just wrap tape around the contact point and call it protected.
Steps
Identify exactly where the duct is contacting the sharp edge: bottom corner, side, or full bottom face.
For duct against threaded rod, use the approved cushion, isolator, sleeve, saddle, or support detail before the duct carries load.
For duct on a sharp strut or metal edge, use the approved edge protection, saddle, bearing pad, or support correction required by the job.
For insulated duct, check whether the insulation or vapor barrier is already compressed or torn at the contact point.
Do not just wrap tape around the contact point and call it protected.
Say this to your foreman
This duct is sitting directly on [threaded rod / sharp strut edge] at [location]. Do you want me to add the approved cushion/saddle/bearing pad, or is there a specific support detail for this?