Time to get the sub floor in so I have something flat to work on and can stop scuffing up my new paint job. Plan is to cut 1/2” foam insulation board for the floor insulation. Next will be 1/2” plywood. All this will be secured with various glue adhesives.
First off, this job requires a fair amount of space since it’s cutting 8’x4′ sheets. Luckily, the street I live on is quiet during the day (it’s a dead end of sorts) and there’s plenty of parking with everyone out at work, so taking up a couple parking spots this wasn’t a big deal.
Insulation: I put the remaining amount of Reflectix I had around the edges of the floor just to use it up. To size and cut the foam board for the floor, I used the old black plastic mat as a guide. (Remember this? I pulled it out in the cleaning phase.) A box cutter worked fine to cut it. In total I used two 4’x8′ sheets cut into a total of four sections. I secured the foam board to the floor of the van using a silicone adhesive that was good for metal, foam, and good in extreme temperatures (in case it gets really cold against the metal). I had to be really careful to not step or kneel the foam board at this point since it was quite delicate and if I was pushing on a valley in the floor ridges it would break the foam.
In the course of putting in the insulation, I realized the black floor mat wasn’t going to be as accurate as I want it for the subfloor and actual floor in the future. I took the time to make cardboard cut outs that fit the floor a bit better and used these as templates for the 1/2” plywood. If I could go back, before I pulled the black mat out I would have done the necessary alterations (trimmed it down, built it out) to make sure it would have been an accurate template to have saved myself the time to make the cardboard cut outs. Anyway, if you’re making cardboard templates, I found that it’s easier to build it up with tape than to have to trim off little bits.
Cutting the plywood was pretty easy once I had the cardboard cutouts made. It was my first time using my new jigsaw! We ran an extension cord from the house down to the van. I had to take the pieces out a couple of times to make sure they fit just right. I glued the wood down to the foam board with an adhesive good for foam board and wood. I only bought two sheets of plywood since I did the insulation with two sheets, but I ended up needing a third sheet of plywood. This ended up being quite annoying because it ended up raining for the next week, so this project dragged on while I waited for a good day to cut the final piece of plywood.
Materials and Costs: Two 1/2” sheets of the fancy foam board insulation with the shiny reflective side (~$13×2), three sheets of OCB plywood (~$14×3), 3 tubes of silicone adhesive (~$8×3), 3 tubes of foam board adhesive (~$4×3). Total cost of around $105. This could have been cut down to about $85 if I had planned the plywood better and used cheaper adhesives.
Take Aways: Cardboard cutouts take longer than you might think. Plan ahead well with the plywood and materials so you don’t end up wasting good work days because you don’t have the right stuff.