Debating on whether this is something I can do or if I need to call in an pro. I have a basement room I'm looking to use as a theater room, and I need to finish a wall to the ceiling so I can hang a projector screen. The top part in the picture is exterior wall, and the lower wall is 2x4 framing up to the top of the rim joist. There's a vapor barrier on the interior side of the lower wall, and the framing is right up against the concrete, no foam board in between. Standard fiberglass insulation in both.
My first thought was to just build a frame to finish off the top half, add some additional insulation, and hang some 5/8 drywall, but I assume I'd need to fill the air space behind this, and I'm not sure if I'd need to remove the drywall on the upper wall prior to doing so, or if replacing the lower wall and framing it to the ceiling would be considered the best practice in this situation. I've hung drywall and done some framing before, but not in a basement, and I'm concerned about creating some moisture issues.
Update: this is for a large 92" projector screen, so I need a flat surface to mount it.