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Community and Q&A

Blue board and plaster

user-901114 | Posted in General Questions on

My walls from the outside in;
Vinal siding
2×6 w/ roxul
1 in foil faced polyiso
1/2 blueboard

What should I do for plaster and Paint? I know the rule is latex with outsulation but what about my set up? Do I use latex over plaster? I’m in zone 6.

I was looking at American clay as an alternative. Anyone use it before?

Thanks, Steve

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  1. GBA Editor
    Martin Holladay | | #1

    From a building science perspective, you can use any type of plaster and paint that you want.

  2. Expert Member
    ARMANDO COBO | | #2

    I've designed dozens of homes in the southwest and south using American Clay for beautiful wall and ceiling applications. Plasters are non-toxic and hygroscopic as well; but best of all is that is made in Albuquerque... ;-)))

  3. user-716970 | | #3

    The wall you describe does not have outsulation. If it is indeed built as you describe, with foil faced polyiso under your blueboard, you can use whatever paint or finish you desire, as Martin has said. Your wall is basically vapor impermiable on the interior.

  4. user-901114 | | #4

    Armando, Any idea the clay perform in humid environments?
    Garth, Correct. The foam is on the interior. Painstakingly airsealed. Had I to do it over, I may opt for outsulation.

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