Replies

1. Expert Member
   MALCOLM TAYLOR | Mar 25, 2019 05:39pm | #1

   John,

   If you are putting the WRB (the Tyvek) behind the foam, the window should go there too. If you want to mount the window on the f0am you should move the WRB out as well.

   One thing to look out for is that if the windows you select don't have enough depth on the outside of the flange, they may not cover both the foam, furring strips, and boards. That will complicate the window trim.

2. 
   user-231615 | Mar 25, 2019 06:33pm | #2

   Ok. I will place window flange flush with outside of foam. And use the foam as the WRB

1. Expert Member
   MALCOLM TAYLOR | Mar 25, 2019 07:41pm | #3

   John,

   The advantage of moving the Tyvek out and keeping it as your WRB is that you can lap and flash the windows as you usually do. If the window is mounted directly to the foam you have to rely on taping the head and jambs - and have to tape the seams of the foam.

3. 
   Peter Yost | Mar 27, 2019 05:58am | #4

   Hi John -

   If you install the window in plane with your exterior rigid insulation, just make sure you follow what is required by window manufacturer in terms of how much of the window needs to bear on supporting material (i.e framing).

   Peter

4. Expert Member
   Michael Maines | Mar 27, 2019 08:16am | #5

   You might want to check out this product, made for this situation: https://www.greenbuildingadvisor.com/article/an-alternative-to-wood-window-bucks.

1. 
   brendanalbano | Mar 27, 2019 11:42am | #6

   With only 1" of exterior foam, is there an advantage to using the ThermalBucks vs just screwing the flanges through the foam into the wall like Building Science Corporation often recommends for foam up to 1 1/2"?