Step 7: More about the floor: insulation
I used 3/4 solid pink foam insulation. I cut to fit. there is a plastic membrane that peels off, I made sure to remove that membrane. I made the pieces as snug as possible. Then used construction adhesive, screws and fender washers to attach.
The tar was still slightly tacky, and my pieces were pretty snug fits. I kind of wedged them in there and they stuck to the tar.