Incorrectly framed new window installation

[Windows on Washington]

If you are doing it, I would stick to the Schluter system of waterproofing. Most bulletproof and well engineered systems I have seen to be honest.

Back to the framing, if there is a second floor above that window, it should be at LEAST a 2x6 header. Depending on floor joist direction, that would be the smallest you could go with, and much more might be required.

[toddinmn]

I agree with WOW on the both, I think the 2x6 is minimal but we I ain’t no engineer so why not go bigger . While you’re at it I would want the sill tilted 5degrees for drainage along with some pan flashing . You may want some Additional framing at the spit and back side which could go horizontal or vertical depending on your spacing. I’d redo the insulation properly with no paper face with a properly installed vapor barrier that goes over the tub lip. I’d also use a product like denshield over dura rock for its ease of use. I would also tilt the interior side of the sill 5 degrees to the inside. Hopefully you got rid of the person that messed up your framing twice already.