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Window rough openings and raw edges exposed to multiple rainstorms: Is this a problem?

88Clayton | Posted in General Questions on

I have a Zip-R sheathed house that is still in framing.  The window rough openings have been unprotected for two weeks now and several hard, heavy rains have poured down on these rough openings, saturating the raw OSB edges and foam.  The windows are scheduled to be installed in a few days.  I tried my best to get my builder and his crew to flash these windows ASAP after sheathing them, but I was unsuccessful.   I would’ve preferred it be protected from the beginning.

My questions are:

1) How big of a problem is it for these areas to get soaking wet multiple times?

2) Should the framers have already flashed the sills, immediately after sheathing around the openings?

3) Does the wood need to fully dry out before window install?

Thank you!

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  1. Peter Yost | | #1

    First advice: since your builder created this issue, have him/her get the answers to your questions. Have him call the manufacturer of the materials and ask them the same questions you are asking here.

    Also get him/her to take moisture measurements (pin type moisture meter) of the wetted materials, commit to drying out the house such that the moisture level is below 15%, and then he/she can complete their work.

    Should your builder have protected the window openings during construction? I know it is different for remodeling than new construction but: when I was a builder/remodeler, routine wetting of the rough frame of the building I did not worry about. BUT, when I knew that it was going to really hammer the building--or it became clear DURING the event that the building was going to get hammered--I dragged my butt out to the jobsite and protected the building.

    Intense wetting often means intense drying is required. And what I worry about most is NOT the exposed surfaces that are easily assessed, but the buried places moisture can remain a very long time (such as underneath wall bottom plates/structural subfloor). See attached photo: 9-inch rainstorm hit this model home under construction several years ago in July. More than 3 weeks later moisture reading in all exposed OSB and framing were in the 12% range. But the bottom side of the bottom plate and the topside of the floor OSB: 27.5% moisture content by weight--REALLY wet.


    1. 88Clayton | | #3

      Makes sense. I’m definitely worried about it’s drying ability before next steps. They plan to use Zip Stretch tape. I’m hopi g it fires out enough before they tape it. I’m afraid the Zip-R foam sill impede the drying. It’s 1” of polyiso. Normal OSB would be drying easikynin both directions.

  2. Expert Member


    If we didn't frame in the rain there would be no buildings in British Columbia. The main concern isn't the wetting, as Peter pointed out, it's making sure things are dry before encapsulating them.

    1. 88Clayton | | #4

      What do you consider encapsulating of Zip-R? Drywall? Or simply tape-flashing the rough jambs and sills?

  3. andy_ | | #5

    Check for swelling of the edges of the OSB.

    1. 88Clayton | | #6

      I did and I have a little bit of swelling.

      1. Trevor_Lambert | | #7

        Swelling is not good, but it might not be the end of the world if it is left to dry out. Structural integrity is compromised, but I don't imagine there's much structural load at the edges of the OSB.

  4. walta100 | | #8

    I was surprised at little water zip sheeting would absorb. I made paths thru the mud around the house and to the burn pile, months later when I pick up the Zip it seemed unaffected.

    Huber company make Zip sheeting biggest product AdvanTech subfloor this products claim to fame is how well it stands up to being wet for weeks on end. My point is there strand board products do stand up to water well.

    I encourage you to find a small scrap of the Zip put it in a bucket of water with a brick on top of the Zip, pull it out after a week.

    I do not think you will have any problem with the tape/ flashing sticking to the green face once the surface is dry to the touch.


    1. 88Clayton | | #9

      That’s good to hear. Thank you. I’ll do that!

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