I installed a window in my basement 2 years ago and in the time since I've realized that I fastened the header incorrectly. Oops. I have to take it apart anyways to re-do the trim and match the other windows better, so I want to just fix it all.
The problem was the sill plate, which should lay flat on top of the header. It is tilted outwards about 10 degrees.
I have 4 options:
1) Wedge the header under it and leave the sill plate to only contact at the corner
2) Wedge the header and then try and screw it to suck it back straight
3) Use the table saw to match the angle on the sill plate and cut the header
5) Use shims to ensure full contact.
I assume the sill plate shouldn't be slanted anyways. What might cause this, is this a bigger issue than I know? Should I also add concrete anchors to suck it back down to the concrete? And do I need to put that foam membrane stuff around my PT framing?
Here's a diagram: