Static field route #19655

What do I do when a flex duct clamp cuts the outer vapor jacket?

Flex Duct Connections & Supports✅ FIELD REFERENCEField answer expansion

📖 Verified core answer

A clamp should secure flex, not slice the jacket. Back off the tension, patch torn vapor barrier, and verify the connection is tight without crushing or cutting the flex.

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Field verification checklist

Check clamp tension before final lock.
Look for sliced vapor jacket or crushed inner liner.
Patch vapor jacket with approved tape/material.
Make sure the inner core is separately secured as required.
Recheck the run for kinks after tightening.

Ask foreman

The tension gun cut straight through the plastic jacket because the clutch was set too high. Back the torque off, and wrap that cut tight with two layers of Mylar tape to seal our vapor barrier.

Text to foreman

Route options

A Correct prep/setup only if the fix is within your assignment and the approved method is clear.

B Hold and document if it affects safety, structural support, rated assemblies, airflow, access, tools, material condition, or another trade.

C Bring the journeyman/foreman the location, what you checked, and what decision you need before the crew loses time.

Do not do this

Do not crank the tension gun until it cuts into the flex jacket.

Why this matters

A torn vapor barrier can cause condensation, insulation failure, and callbacks.

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, pressure/material schedule, and AHJ/code requirements.

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