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Community and Q&A

Cold weather roof profiles

RobertContractor | Posted in GBA Pro Help on

For a vented wood frame roof with metal roofing and batt insulation is it advisable to apply poly to the heated side of the space?

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Replies

  1. Expert Member
    MALCOLM TAYLOR | | #1

    Robert,

    You need a warm side air-barrier. Poly works well except in hot humid climates.

  2. anrew | | #2

    Products like CertainTeed MemBrain or Intello Plus are Class II/III vapor retarders that allow the assembly to dry to the interior when humidity levels rise — exactly what’s needed in mixed or cold climates. At least you don't need to deal with the hostile work environment letter https://help-center.pissedconsumer.com/how-to-complain-about-hostile-work-environment/ like some of us here.

    1. Expert Member
      MALCOLM TAYLOR | | #3

      anrew,

      The roof is vented so it dries to the outside. Vapour-drive in cold climates is to the exterior.

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