That is a rough saw 3/16 plywood edge poking that membrane.
The sandwich side wall (as I understand it) from inside to outside:
3/16 inch fabric/wallpaper covered marine grade plywood panel
1 1/2 inches of Styrofoam/aluminum tubing frame
3/16 inch marine grade plywood panel
1/16 inch Filon Fiberglass panel
All layers bonded together with marine grade adhesive.
IMO, you need to cover that with a strip of Eternabond Tape for the entire compromised edge. Remove the metal hold down strip and over lap the tape enough to have the edge covered by the metal and at least 2 inches of tape on the roof. Re-install the metal strip.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
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