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Community and Q&A

Frost & condensation on TechShield

home4two | Posted in Energy Efficiency and Durability on

I’m building a single story house in Walla Walla. I have frost on the underside (TechShield) side of roof sheathing. I have R-60 insulation and was careful to seal all penetrations through ceiling and am using airtight cans.

The house is approx 2,450 sq ft. I have ridge vents and 28 – 8×16 soffit vents.

I did have some vents blocked by insulation and have fixed that. I also have energy-heel type trusses.

I know that painting, mudding and texturing can contribute a lot to moisture, but my hygrometer says around 38% humidity in living space. Also have 4:12 pitch which lessens stack effect.

Any suggestions welcome on how I can dry out my attic.

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  1. GBA Editor
    Martin Holladay | | #1

    For the time being, I wouldn't worry about a little condensation on the underside of your roof sheathing. If I were you, I would wait a few months. The weather will change, and your construction moisture will dry out. You probably won't see any problems next year.

    If the problem persists, your ceiling may have significant air leaks. The way to diagnose that type of problem is with a blower-door test.

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