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Community and Q&A

Foam board insulation

benwood1 | Posted in General Questions on

I am getting a sunroom built. they built a deck and it will supposedly a 4 season room. the subfloor has been nailed it already and I see plastic under the subfloor but they now said there is no insulation. the suggestion was made to get foam boards to add along the skirting instead of tearing up the floor to add the r-30 insulation. please advise if this will work and if I will run into any problems by only doing this. thanks.

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  1. Paul Kuenn | | #1

    Ben, a lot will depend on your climate zone. If it's cold in winter outside, the floor will be cold unless you take the exterior insulation down below the frost line. It will still be cold but probably above 40F. If the ground is below freezing, all your heat will be traveling down towards the cold.

  2. benwood1 | | #2

    so the foam boards wont help at all? do I need to tear up the floors and just install insulation?

  3. GBA Editor
    Martin Holladay | | #3

    Contractors have to meet the building code. If this is a "four-season room," presumably it needs to be able to be heated in the winter.

    The building code requires floor insulation: a minimum of R-13 insulation in Climate Zones 1 and 2, or a minimum of R-19 in Zones 3 and 4, or a minimum of R-30 in Zones 5, 6, 7, and 8.

    Your contractor is responsible for fixing this problem, because it doesn't meet minimum code requirements.

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