Originally Posted by Dav L
If the wood is rotted or not secure to the filon, then replace it while you have things opened up. It's really not that much more work if you are doing this. Might as well get it all done. You can cut the wood with a reciprocating saw (a "Fein" saw) down the studs and slide it all out. Then dry fit new Luan, and then glue and slide it back into place. I would also double it where the gaps are (I would put the board breaks inbetween the studs) with an additional layer of glue / luan so the breaks don't show on the outside of the filon.
You can use spray foam to make the stud to Luan firm.
Then, redo or add any wiring, replace the insulation, replace the inner wall, do your cosmetics, hang your stuff.
It’s fiberglass, not filon so it’s already more rigid. I was thinking of just putting the foam board directly against it.
After some more thinking however, it would creat a thickness issue that I’d need to resolver on the interior anyway since the foam is 1”. So rather than doing foam against the fiberglass and 1/4” inside panel, I’m headed to HD to grab 1/8”.
It is impossible to make the seams on an aluminum stud since there is only 1/&” between it and the fiberglass....not possible to cut it.
My plan is to make the cutout portions as square as possible and use PL Max for the pane/fiberglass bond. Then foam adhesive for the panel/foam bond.
Right now I’m estimating 50-60 sq ft total. Ceiling is 80” tall and at most, the widest repair will span 8’.