Correcting a mistaken window/WRB interface
Hi all –
In three windows, I absent-mindedly forgot to ‘flap back’ the WRB (Tyvek) before installing the window. I realized my mistake and now do the 45* cuts, flapping back the Tyvek, installing the window, then lay the Tyvek back down (tape the cuts), then put a layer of butyl tape over the entire thing.
For the 3 windows where the WRB is behind the window flange (instead of in front of it), what would you do to remedy this mistake?
I was considering cutting a wind0w-wide slit just above (maybe 1/4″) the flange, then sliding a piece of flashing in there, and applying butyl tape over that. The flashing would overhang the face of the window. Any water coming down the WRB would then go over the flashing and be directed outward.
Any other suggestions?
(Picture shows current flawed installation)
Replies
Been there done that.... I ran a second layer of wrap (a bit wider than the window) from the top plate down to the top of the window flange effectively maintaining the drainage plane without cutting the original wrap. I'd tape up the window flanges first both the top and the sides making sure the new top layer of wrap and tape overlaps the tape on the sides.
Cutting the slit in the paper and creating overlap would do the trick as well but you run into a small risk at the two ends of your cuts that are difficult to properly flash.
This is a very good solution in this case, as the top plate is only ~ 18" above the window (and this is the top floor, so the eave/soffit is right there too). Any water that makes it onto the piece will be kept in front of the drainage plane. Only downside is doubling up of Tyvek but shouldn't be an issue (I'll make sure to pound down any high nails/bumps as the extra thickness of the wrap may exacerbate any projections)
I'm glad I'm not the only person who's done that!
I would cut a slit about 4 inches above the window, and 6 inches beyond the sides. I'd side a piece of tyvek up in there a few inches then down to cover the window flange. Then tape the ends, running the tape about 6" above the slit. To put a belt with the suspenders, I'd caulk the top of the tape with PL.
Both good ideas, and if nothing else, thank you for the moral support. A bit of a head-smacker. Next time I'll start with the most sheltered window to make my screw-ups on!
By the way, what is PL? poly something? pro something?
PL: https://www.homedepot.com/p/Loctite-PL-9-5-fl-oz-White-Heavy-Duty-Sealant-2163657/300827434
Polyurethane sealant.