Static field route #19084

What do I do when an uninsulated supply tap is sweating and dripping?

Insulation, Liner, Vapor Barrier & Condensation🟨 CHECK FIRSTV190 answer-gap expansion

📖 Verified core answer

Cold supply metal exposed to humid plenum air can sweat. Dry it, verify insulation/vapor barrier requirements, and wrap/seal it so humid air cannot reach the cold metal.

Open in Field Rescue Open category

Field verification checklist

Confirm the duct is cold supply and identify humidity source/space condition.
Check whether insulation is missing, damaged, compressed, or open at seams/collars.
Dry the metal before wrapping or sealing.
Verify specified insulation type/R-value/vapor barrier detail.
Check nearby diffusers, boots, and seams for more sweating.

Ask foreman

The supply tap at [location] is sweating and dripping. I dried the metal and checked missing insulation/vapor barrier. Do you want it wrapped/sealed per the insulation spec and nearby cold surfaces checked too?

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 airflow, access, life safety, pressure class, rated assemblies, equipment, or another trade.

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

Do not do this

Do not wrap wet metal loosely and leave open seams where humid air can reach the cold duct.

Why this matters

Condensation can ruin ceiling tiles, create mold concerns, damage finishes, and make the HVAC install look bad after turnover.

Verification basis

Approved drawings/specs, project coordination drawings, manufacturer instructions/submittals, shop standards, foreman/detailer direction, employer policy, and AHJ/code requirements.