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Community and Q&A

Brick sealer on a wall with exterior insulation

whitenack | Posted in Green Products and Materials on

Hi all,

We are in the final stages of completing our Pretty Good House. We went with (from inside to outside…) 2×6 stud walls filled with damp blown cellulose, 2 layers of 1.5″ polyiso rigid insulation, house wrap, air gap, brick.

The builder is suggesting we use a brick sealer (Siloxane) to help slow/stop the wicking of moisture into the brick.

Is there any problem with this? I could see where it could be a benefit if it truly seals the brick from absorbing water, but I also wonder about it preventing water that finds its way behind the brick from drying out.

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  1. whitenack | | #1

    I just realized I omitted the sheeting when talking about our wall construction. We used 5/8" OSB between the 2x6 studs and the polyiso.

  2. GBA Editor
    Martin Holladay | | #2

    The best way to keep bricks dry is with a high foundation and good roof overhangs.

    Siloxane is sometimes used in a difficult situation, when all else fails -- usually on a poorly designed house with water-entry issues. On a new house, siloxane shouldn't be necessary.

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