how did you remove the original deck?
did you leave a small edge of original deck hanging out or cut it flush with the liner?
if you did leave an edge, are you going to put the new deck on top of that, or butt it flush to the edge?
just asking because if you are doing the former then yes the liner & edge need to be secured to something solid, the liner alone is pretty flimsy. I'd glass it down to the outer stringer. When I cut my deck out the liner was about an inch away from the side of the hull, not right against it. Ended up cutting about 2 inches off the bottom of the liner so I can glass the deck to the hull side (plus my outer stringers are pretty screwed up & needed work), then glass the liner to the deck using a thin strip of foam sheet as backing for the new bottom 2 inches of liner.
