Covered every inch of the floor and noticed a huge difference in sound on the road.
The furring strips were glued straight to the sound deadener in the deepest three grooves.
Coated the wood in polyurethane for water protection.
Using the Eucaboard templates to mark the SSR for cutting.
The plywood was cut a 1/4 inch from most of the edges to prevent rubbing on the van.
Three coats of spar polyurethane on all of the sub floor plywood. I didn’t sand the polyurethane and used a foam roller to add even more texture so the vinyl flooring would grip.

Used some twine for a screw line.
Neighborhood cat visits during the build.
Secured with stainless screws.

Backer rod at the edge of the plywood and below the vinyl flooring to keep the silicone near the edge of the plywood and vinyl flooring.