I have an existing floor-to-ceiling narrow deep closet (11" wide opening, straight in). I want to cover the bottom 5" with drywall, so it'll eventually look like this:
Where the lavender piece indicates what I want to add. The salmon portions are existing wall.
I'm not sure how I should go about this. Both of the corners have a metal corner bead, which seems difficult to cut. I was thinking of screwing an 11" 2x4 cross beam behind the patch, and then screwing the drywall to that piece. That would have a second advantage in that I was going to add a melamine shelf on top, so the 2x4 would provide the requisite support for this shelf.
Is that the best approach? If so, how should I screw the 2x4 into either side? I tried driving a 2.5" screw at a 30 degree-ish angle, but it doesn't appear that strong.