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Community and Q&A

Using used (recycled) rigid insulation

nepal | Posted in General Questions on

hey guys, thank you in advance to any that answer or help with my questions.
i recently bought some used 4″ Dow Roofmate rigid insulation from a roofing contractor. i plan on using it on my crawl space foundation walls. one side of the insulation is a bit distressed and by distressed i mean it has cuts, slices and dents. will this affect the performance of the insulation? should i face the distressed side against the wall or the good side against the wall? would it help at all to paint the distressed side with a latex paint? any thoughts would be appreciated. thank you

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  1. GBA Editor
    Martin Holladay | | #1

    The dents and scrapes will not significantly affect the performance of the insulation. You can face the dents either way.

    Note that most building codes require rigid foam in a crawl space to be protected by an ignition barrier or a thermal barrier (usually drywall).

    For more information on attaching rigid foam to concrete walls, see these two articles:

    Building an Unvented Crawl Space

    How to Insulate a Basement Wall

    -- Martin Holladay

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