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Community and Q&A

Framing splayed window openings with double frame walls

timdes | Posted in Green Building Techniques on

I’m building a double frame house with 2×4 ext, 2×3 int offset. I know that usually people line up the interior and exterior framing at doors and windows to make the boxes. Are there any words of wisdom or ideas about details for building boxes for “outie-style” windows with sides that are splayed out at 45 degrees?


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  1. GBA Editor
    Martin Holladay | | #1

    GBA reader Dick Russell posted a few comments on this topic on a previous Q&A page:

    He also posted a color photo of his own window with splayed jamb extensions, plus a link to an Environmental Building News article with a photo of such a window. I'll post the photos below; perhaps they will inspire you.

  2. dickrussell | | #2

    Tim, I searched through my construction pics, and this is the best I could find showing framing around the windows. In my case, the inner and outer studs are aligned, vs yours being offset. Around windows, some sort of adjustment is required. In my pic, you can see that a piece of Advantech spans across the inner and outer frames at the top and bottom. After window installation, the sides were covered with maple veneered plywood. That's a detail best left to the framer. I just told mine what I wanted for the splayed back effect and left implementation to him. He worked it out and showed me what he planned on doing, and that worked well.

  3. timdes | | #3

    Thanks so much. This is really helpful. I'm also wondering whether it will be possible to spread the framing to 24" oc if I want the upstairs floor joists on 16", since there is a 2x3 interior wall that will be taking some of the load. The joists won't be stacked, but landing on 3/4 ply that holds the inner and outer top plates together. The roof trusses will be stacked directly over the 2x4 exterior wall studs.

  4. GBA Editor
    Martin Holladay | | #4

    So your floor joists will land on the single top plates of two parallel walls, with plywood joining them? That's not the same as double top plates. Talk to an engineer.

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