Caulk Window Trim/Extension Jam?
I’ve added 2″ of polyiso exterior insulation on top of ZIP sheathing, which is my WRB. The windows are flashed properly with beveled shingle and ZIP stretch tape as the sill pan. The polyiso overlaps the window flanges and flashing tape.
I have framed out 1″ channels that will be for picture frame trim/extension jams (windows are installed in “innie” configuration). Even though I’ve got the windows flashed properly, I’m wondering if I should caulk the inside joint/seam between the exterior insulation and where it meets the flashing tape?
On the one hand, not caulking it would allow water to run down behind the insulation and along the designated WRB. On the other hand, my gut and inclination is to always keep water away from the windows flanges.
What advice would others out there offer? (see photos)
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