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Aron_Robinson | Posted in General Questions on

Greetings all. We built our house 5 years ago with much good guidance from this site. We installed a wall assembly with 1/2 inch osb, then a layer of housewrap, then a layer of 1/2 inch foam board with the seams sealed and flashed to outtie type windows. We installed Certainteed cement board siding. This siding had manufacturing issues and was subject to a class action settlement because it would crack, etc. We have several cracks, etc. We have filed for the claim and are preparing to replace our siding with James Hardy. Wish we had gone with that brand in the first place. I want to ensure I have no water problems on the new install. Would there be any problem installing a new layer of housewrap and reflashing around the windows before having the siding installed? There would basically be a layer of housewrap on either side of the half inch foamboard. Any help is greatly appreciated. I just want to ensure I have no water penetration and no moisture problems in my wall assembly. Regards, Aron

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  1. GBA Editor
    Martin Holladay | | #1

    In would be helpful to know your climate zone. Since your layer of rigid foam is quite thin, I'm assuming that your house is in Climate Zone 4 or somewhere warmer.

    In general, having two layers of housewrap is not a problem. Ideally, however, you know which material is your primary WRB. In your case, presumably the first layer of housewrap that was installed is your primary WRB -- and presumably you remembered to install sill pan flashing on the window rough openings, with the sill pan flashing directing water to the exterior of the first layer of housewrap.

    The second layer of WRB (in your case) won't be the primary WRB, but it can be used to limit moisture entry. Since housewrap is vapor-permeable, adding an additional layer won't cause any problems.

  2. Aron_Robinson | | #2

    Thanks Martin. Yes we are in zone 4 in Kentucky.

  3. Aron_Robinson | | #3

    Martin...I spoke to my builder a few days ago and he admitted that they may not have installed sill pan flashing. I've been given two siding estimates and mentioned this to the companies. I mentioned removing and reinstalling the windows to one of the companies. He said I might be able to avoid doing this because it looks like the improper size trim and z flashing were not installed with the cement board siding. I still have concerns about water entry. My thoughts are that if I already have the siding off I might as well have them remove the windows, properly flash the sills etc, and reinstall. I would have them do this with the second layer of newly installed housewrap that would go over top of the half inch foam boards. Would you recommend this or go by the siding companies recommendation? Once again, I would have the older layer of housewrap sandwiched between the osb and foam board and the newer installed housewrap between the foam board and siding. I'm in Kentucky.

  4. GBA Editor
    Martin Holladay | | #4

    OK, you filed a claim against the siding manufacturer. Now you may want to file a claim against your builder. Depending on the brand of windows you used, your builder may have violated the window manufacturer's installation instructions -- providing the basis for a claim against the builder.

    For many years, most reputable window manufacturers have required the installation of sill pan flashing. If your builder didn't follow those instructions, he could be sued. I'm not saying that you should go that route -- but you may be able to negotiate for some free labor from your builder.

  5. Aron_Robinson | | #5

    Thanks Martin. He's actually doing the strip off of the siding at no charge; will talk to him about windows as well. Another company residing. Should I have them try to tie in to the old housewrap under the foam and flash with that or do as I mentioned and install another new layer over the foam, pull out the windows, and flash with the new wrap?

  6. Aron_Robinson | | #6

    I have attached a pic of the house w/foam board before siding was installed. The builder cut out osb strips and nailed them flat around window to better secure it then taped from the foam board over to the window. I think this would create obvious problems if water got behind the tape to the osb strips that are approx. 4 to 5 inches wide. Would it also be better to remove these; replace with foam board strips, nail through half inch foam board to the osb sheathing underneath, extend original housewrap flashing over window or just install the second layer of housewrap and flash with it after pulling windows out? The builder said he would do the labor to properly flash at no charge.

  7. Aron_Robinson | | #7

    We went back and taped all those foam seams also, but I now that later that tape could possibly pop. I just want to get it right now that all that siding is coming back off.

  8. GBA Editor
    Martin Holladay | | #8

    Your descriptions are a little confusing, but I don't think that the solution is confusing.

    If there are no sill pans in the rough openings under the windows, then I don't think there is any way to flash these rough openings without removing the windows.

    Once the windows have been removed, you will need to install sill pan flashing. When that's done, the sill pan flashing can be tied into one of the layers of housewrap. I don't think it matters which layer of housewrap you direct the water to, although I would probably direct the water to the outermost layer of housewrap if I were you.

  9. Aron_Robinson | | #9

    Got it.....thanks Martin. That's what we decided to do. Builder will pull all windows and reflash and reinstall at no charge to a new housewrap. Seemed like quickest way to deal with problem. Then siding company will reside. The only upside to this siding debacle with the certainteed settlement is that it will allow us to better address this window problem also. We had taped taped the seams on that foam board. Do you think it would be advisable to pull the tape on it before recovering with new wrap or just leave it?

  10. GBA Editor
    Martin Holladay | | #10

    Taping the seams of the rigid foam is good. Leave the tape on, and then install your new layer of housewrap.

  11. Aron_Robinson | | #11

    Thanks Martin

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