Completing the floor
This is a temporary floor, so I’m using cheap 1⁄4” maple plywood, mainly to see how well it stands up. We decided to paint it with remaindered house paint, again since it’s temporary.
Eventually we’ll put down a more robust floor, probably covered with sheet linoleum or vinyl, but this will do for now.
To locate the holes for the tie-down points in the plywood, I used a trick (borrowed from someone I’m sure) for marking the plywood. Basically, take an M8 1.5”/40mm bolt, drill a hole in the center of the head, insert a point (small wire, ball bearing, etc.) and set the bolt so it is slightly proud of the surface. Then place the plywood on top, and hammer down over each tie-down point. This marks the tie-down points on the plywood, and then I could drill appropriate (oversized) holes at the marked points. I didn’t have any ball bearings, so used finishing nail tips, secured with epoxy. Not ideal, one of the points eventually fell out, but good enough for the 8 locations I needed. A bit of permanent marker on the nail head also made it easy to find the mark.
Marking the tie-down points on the plywood
With appropriate equipment and materials, it would be much more effective to take M8 rod, cut it to length and grind a point onto it. Lacking access to Tech Shop, I asked my father to mail me some M8 points, but only requested 1⁄2” length, not 1.5”, so couldn’t use them for this. They’ll be helpful on the walls.
Since polyiso is fairly easy to compress or damage, I didn’t want to have it right at the door entries. Instead I added a 1”x1” HDPE strip at each door.
This took more work than I expected, since the corrugations in the original floor of the van were within 1” of the edge of the plywood at the rear doors. I routed a 3⁄8” channel in the 1” HDPE and that worked well. I also covered the plywood with 3⁄4” aluminum angle, screwed to the plywood and HDPE. That gives a simple and fairly clean edge at each door sill.