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Capillary break on monolithic pour

Nicole_OregonCoast | Posted in General Questions on

We are building a conditioned crawlspace on the Oregon coast. Our original plan had been to use waterproofing to create a capillary break between the footer and stem wall. However, my concrete contractor told me that he does monolithic pours and pours the footer and stem wall at the same time. What would be a good option in this case?

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  1. Expert Member


    Capillary breaks are used by an infinitesimally small group of builders. I'm not saying they aren't a good idea, but I don't think you could put them anywhere near the category of necessary parts of a foundation design - especially for crawlspaces.

    If you want to help limit the moisture in the foundation walls that moves into the crawlspace, lap the under-slab poly up the walls and seal it to the sill-gasket.

    1. Nicole_OregonCoast | | #2

      Thank you.

  2. jberks | | #3

    I'm with Malcolm in that most contractors don't do capillary breaks.

    For a crawl space it might not be worth the effort and as Malcolm mentioned, I'd say it's easiest to continue your subslab poly up the walls to keep ground moisture out. It's been discussed here in the past that moisture does not affect the longevity of a concrete foundation wall.

    I personally like monolithic pours from a logistics point of view. I have personally done a layer of poly on the underside of the footer as a capillary break. It was a pain to do.


    1. Expert Member
      Dana Dorsett | | #4

      >" I have personally done a layer of poly on the underside of the footer as a capillary break. It was a pain to do."

      I've never used it, but the FastFoot product is probably quite a bit easier than wrestling in some sheet polyethylene into a standard concrete form:

      1. jberks | | #6

        I looked at that as well, it was actually what inspired me to do poly on the underside.

        The fast form footing assembly looks horribly complicated and time consuming. I also don't like that it's not a slab, little less surface area on the ground... I dunno, maybe one day if I get to see it in real life instead of a YouTube video. I don't want to knock it while never trying it.

  3. GBA Editor
    Brian Pontolilo | | #5

    Hi Nicole.

    I agree with what has been said here so far. Wanted to also point you towards this article, which you may find helpful: Capillary Breaks Above Footings.

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