Head Flashing Design + Should I notch trim over end-dams?
Hello again! Zone 2A, new build. Nail-fin windows in plane with the sheathing/WRB. ½” rainscreen, with 5/4″ live edge siding and 3x trim (mounted to RS). Steel head flashings on *both* the windows *and* the trim. 3 questions:
1) With respect to the flashing on the head-trim: How far should it project? General rule for windows is 1/4″ I think? But I’ve heard that for trim, when the window below has a metal drip cap, zero projection is okay — because any water that runs down the face of the trim (and wicks underneath it) will just land on the *window’s* head flashing.
2) Does a 5/16″ L “drip leg” plus a 1/4″ L kickout sound okay? Making these elements as big as Hammer & Hand (and FHB!) recommends covers up a lot of the window frame’s head. Looks bad on the double hungs (I made a prototype).
3) My head flashings will have end dams, and I’ve seen builders like Malcolm Taylor here suggest that you should cut small notches in the head casing (trim) to allow it to be lowered over your end dams (to the normal ¼” gap b/w trim and window frame). What’s the point of having a greater-than-1/4” H end dam, if you’re blocking off the top ¼” of it? Why not just make it ¼” H?
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