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Which way does rigid foam insulation face?

lloydgack | Posted in General Questions on

i will be using the cut & cobble method to insulate our rim joints in a zone 5 house. Just a couple final questions…

1. EPS or Polyiso?
(ive read that in cold temps EPS retains it’s R-value better.)

2. i will prob. be using Tuff-R or Super Tuff-R and i get conflicting info as to which face of the boards should should face inward. it seems to depend on the situation.
(and getting any info from the company is impossible)

thank u

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  1. GBA Editor
    Martin Holladay | | #1

    Q. "EPS or polyiso?"

    A. Either one will work fine. For more information on this issue, see "Choosing Rigid Foam."

    Q. "Which face of the boards should should face inward?"

    A. With most brands of rigid foam, it doesn't matter. However, if you are installing a brand of rigid foam that has foil facing on just one side, the foil facing should face the interior.

  2. lloydgack | | #2

    thank u martin

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