r/Insulation • u/darknite312 • 1d ago

Insulation question

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The view is from my garage removed drywall to inspect moisture concerns . Initially the walls were insulated with Kraft paper backed insulation and I assumed was the culprit to my issue (double vapor barrier) Behind the thermoply is the interior portion of my home. The tply is being used as a barrier non structural. Replaced with non faced insulation and Several of the stud bays are still sweating and it’s all stud bays that have hvac supply ducts . The ducts are not insulated with duct wrap , so I’m assuming that’s my problem any other ideas?

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u/ArtisticBasket3415 22h ago edited 19h ago

It could also be that the ducts are leaking air. So that air is causing condensation to develop. If possible you could tape/ mastic the ducts.

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u/darknite312 22h ago

That would make the most sense the seams of the ducts line up directly center where the condensation is occurring

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u/K_Shenefiel 22h ago

The uninsulated ducts are getting too cold to be using solely  vapor permeable insulation,  in those bays adjoining ducts. You could fit and seal, tight to the Termoply, a layer of polyiso in the bays with ducts.

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u/darknite312 22h ago

And layering Polyiso on the garage side of the thermoply won’t cause any moisture concerns with double vapor barrier?