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Community and Q&A

Bottom Flange on Innie Windows

svalenziano | Posted in General Questions on

Hi All, after reading about all of my options on GBA, I’m using the flashing methods described in this YouTube video (  At 1:13, you can see that this method does not allow for the bottom nailing fin to be utilized, unless I’m missing something.  Living in central NC, where hurricanes regularly blow through, I’m wondering if I should fasten the bottom jamb to the house in some way.

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  1. kbentley57 | | #1

    I think you’re fine to nail the bottom flange, just not seal it further with tape or caulking.

  2. Expert Member


    A lot depends on what kind of window you are considering. That animation sort of skips over how you will need to extend the sill, jambs and head for an innie install by showing a window that completely fills the wall from inside to out - something you are unlikely to find.

    There are lots of details on this site for installing innie windows. Stephen Sheehy's blog shows one. If you want to use flanged windows you will have to make sure the rough-opening is framed large enough to accommodate them and then fur in around the opening to provide backing to attach the fins and support the window.

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