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  1. GBA Editor
    Martin Holladay | | #1

    In most cases, the first step is to flash the rough opening. The flashing required for the rough opening needs to be integrated with the WRB -- in your case, the Typar.

    Once the rough opening has been flashed, the window can be installed. In most cases, the bottom flange and the side flanges are installed on the exterior side of the housewrap. At the window head, slits are made so that the housewrap can overlap the top flange. In some cases, peel-and stick tape is used at the jambs (and sometimes the head, but not at the bottom flange) to complete the installation process.

    For more information, see the 8-part GBA video series on window installation. The first installment of this video series is called Window Sills That Won’t Rot.

  2. Joshua Goldberg | | #2

    Thank you, Joshua

  3. Expert Member
    Malcolm Taylor | | #3

    There are many ways to successfully flash windows. What all of them have in common are:
    - Sloping the sill and installing a pan.
    - Lapping the layers of WRB and flashing so that they drain to the outside.

    While I appreciate Martins' injunction that you are best to start by flashing the rough opening, I've moved away from that for a couple of reasons.
    - Because the area between the framing and the window jamb is typically sealed with caulking or foam, it's easier to get a good seal if the WRB and flashing doesn't extend into the Rough opening.
    - If the window itself leaks and water gets behind the frame, I can't see how the location of the flashing (in front or behind the flanges) makes much difference.

    Again, many ways work, and a lot of this comes down to individual preference. I like to flash windows like this - but include a metal head-flashing with end dams:

  4. GBA Editor
    Martin Holladay | | #4

    Something's wrong here. Joshua posted a question two years ago that (apparently) didn't mention windows. My two-year-old answer mentions windows, which leads me to believe that part of Joshua's original question was lost when this Q&A page was migrated from the old web site to the new web site.

    Then, out of the blue, Malcolm decided to post a new comment on this two-year-old thread. It's all a little baffling.

  5. Expert Member
    Malcolm Taylor | | #5

    It was in the recent Questions and Replies on the front page. A glitch I guess.

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