Cut the fiberglass reinforced panel (FRP) from the front of the box. This strip will become the center part of the angled air dam surface.
The glue must have let go years ago. It just fell off once the perimeter was cut.
Then it was trimmed to fit the air dam.
I put the air dam in the garage as we expect 1/2" rain over the next two day. I covered the front wall of the box with some scrap OSB.
I'll glue the FRP on tomorrow. Then we'll add aluminum above and below as well as on the sides.
The flashing details are still rattling around in my head. Some things just have be be dealt with as they happen during installation.
