Insulating a Sprinter Van

The last few weeks I’ve worked on insulating the van, putting panels up, and creating air vents. To insulate, I used a “reflectix sandwich” with denim insulation inside. This plan should do a good job of preventing conduction, convection, and radiant heat transfer.

Selecting the insulation was long decision riddled with analysis paralysis. A small closed off van is much different from a house regulated by building codes. VOCs and anything else that can be inhaled has to be taken into account. Aside from cotton fibers and boric acid, the Ultratouch Denim insulation isn’t too bad. Most vandwellers seem to stray away from demin insulation because it can absorb moisture. So they’ll go with a hydrophobic insulation like thinsulate. Makes sense at first, and I was even planning to do this. However, the manufacturers of UltraTouch claim that it can absorb and release moisture as needed. You’re in a van. You’re creating water vapor. It has to go somewhere. Just using a hydrophobic material or a plastic vapor barrier does not change that fact. So you can either do your best to have good ventilation (air vents + Fantastic Fan) to remove most of the moisture and choose an insulation that can absorb and release moisture, or you can allow the water vapor to condense on your vapor barrier/hydrophobic insulation, drip down, and rust your van.

Overall I chose the denim because it is:

  1. safe (relatively)
    1. boric acid
    2. cotton/polyester fibers
  2. easy to work with
    1. no gloves needed
    2. easy to rip with hands
  3. easily accessible
    1. Home Depot
  4. affordable
  5. the perfect thickness for a sprinter van
    1. 2″ for the multiuse pack
  6. can absorb and release moisture
  7. pretty good at absorbing air born sound waves

I put the first layer of reflectix on using small pieces of Scotch Extreme mounting tape. I originally wanted VHB tape, but couldn’t find any at Lowes. I was very impressed this tape. Each panel only has about 1 inch of tape total and it held well. The surfaces have to be clean and dry. Amazon Link: Scotch 414/DC Extreme Mounting Tape, 1 by 60-Inch, Black
Home Depot link: Reflectix


Then I built a frame out of furring strips. Crappy wood, but it is cheap. I wasn’t too worried about it being straight. When the boards were bowed, I made sure to arc them upwards. It made the floor a little springy, but once everything is built that should stop.


Demin Insulation fit perfectly. Home Depot: Ultratouch Insulation


I added some more bridges as an afterthought.


The second layer of reflectix insulation was taped to the bottom of the plywood floor.


The original floor fit right in. I screwed it to the wood frame, but not to the van itself. I didn’t see a point. It’s so tight that I don’t think it’ll be sliding around. Less holes in the van to rust.


To put the denim in these sections was a challenge. My first thought was to use string. This didn’t work. I couldn’t get it tight enough without ripping the string.


So I used duct tape instead. I only needed it to hold long enough to put the panels on.


Second layer of reflectix. I just used basic foil tape for piece these together.


I decided to use the original wall panels to save money and time. I used the existing holes and screws too. They’re a little beat up, but maybe I’ll paint them some day.


I repeated the same process for the ceiling.


This seemed to hold pretty well with a ton of foil tape.


I keep telling myself this is a learning process…this was the next morning:


So I cleaned up and put the ceiling insulation in a trash bag. I’ll wait until the day I put the ceiling panel up to redo it. I got started on the door panel to change my focus. Cardboard makes a great template.


Everything will be 1/8 plywood. I don’t want to spend extra on fancy plastic materials. I also didn’t want MDF because it falls apart.


I was proud of this.


I used one panel as a template for the other. The second one had to be modified a bit because of the door latch.


Covered the back of the panels with reflectix using two tiny pieces of scotch extreme mounting tape.


Finished product:


To make the vent holes, I cut through the wood floor with a jigsaw in line with the previously cut holes. Here you can see the little metal tabs that the vents will sit on.


I cut a section from 4″ PVC to fit in the hole.


I traced the pipe and cut a section from this sign.

IMG_20160201_125710 IMG_20160201_125722

Then I screwed aluminum mesh to the PVC.


It’ll sit like this and I’ll probably throw some polyester batting in the hole as a filter:


I saw this at Home Depot and it was the perfect size for what I needed.


Found the BBQ air damper on the interwebs Here. I bought three of the 4 inch version.

IMG_20160201_134214 IMG_20160201_134209

It was super easy to cut with a box cutter.


Then I screwed the top on to the PVC pipe. I made three of these vents and they’re all placed in location where they won’t be walked on or tripped over.


This is definitely going slow, but I’m learning a lot. I only get frustrated on days when I’m in a rush. I’m moving the deadline to the end of February. Sounds almost impossible, but I’ve been putting in about 12 hours of work a day between research, ordering, and labor. So I’m determined to leave by March 1st whether I’m finished or not. A lot of things can be finished up on the road.

The feeling of accomplishment I get after finding my way around some strange design challenge is amazing. I’m really enjoying this process and I’ll never forget it.

I need to make these posts shorter. I’ll try to split them up better.


This time around I propped the ceiling reflectix up with a piece of wood and I also screwed it to the ceiling ribs in some places.


Cut out the fan hole with a box cutter and poked holes for the solar panel wires.


I made the Sliding door panel the same way I made the back door panels.



I initially forgot to make room for the handle to swing open.



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  • Richard Hauser

    How is this setup for sound insulation? Is the denim compressed enough to muffle the metal skin of the van? Happily Homeless started with RattleTrap sound deadener which is pricey and a hassle to install, but I wondered if compressed insulation would work about as well if it was compressed enough to keep the skin of the van from vibrating. Also for a similar reason, why doesn’t anyone look at rockwool as insulation?

    • Joe

      I’ve read that the denim is 40% better at sound proofing compared to fiber glass. I kinda feel like the loaded mass soundproofing products aren’t necessary. I can sleep pretty easily even in the hardest storms.

      • Richard Hauser

        I’d just be a little worried about the moisture absorbency of denim and the how that would affect it’s insulation qualities and also how that moisture flow might encourage rust. On that note, if you treat any more rust, I’d rather you went with one of the rust converting treatments. POR-15 is the one I’m familiar with, it converts rust into primer and then the solution should be permanent.

        • Joe

          I also meant to say that I have seen a few people use rock wool in vans. It’s a great option. I finally decided demin would be easier to install and cut into the odd shapes. Also I wanted something that could accept and release moisture.

          Like you, I was also concerned about moisture absorption. Rock wool is awesome because it doesn’t absorb moisture. Hot moist air will still flow toward the cold metal in a van. If I used rock wool, then it would condense on the rock wool and drip off. Eventually it would pool on the floor. The manufacturer of the demin insulation claims that it can accept and release moisture. When it accepts moisture, it doesn’t come in contact with the metal of the van because there is a layer of reflectix. Moreover, I put in so many air vents that I shouldn’t have much vapor build up from inside.

          I think rustoleum has a rust converting product. I’m sure I’ll constantly be fixing rust.

  • Terri Liebowitz

    Hi, I’m enjoying your blog; the details are great! I have a question: when you re-installed the original wall panels, how did you find the screw or rivet holes behind the insulation? Or did you make new holes?

    • Joe

      Thanks! Haha excellent question. I almost forgot how frustrating that was. First I slid my hand behind the reflectix to find the top right and top left holes. Then i poked a hole through the reflectix to mark it. My favorite method was to use a big nail to dig around until I lined up the hole in the panel with the hole in the van. Then I held the panel in place and quickly drilled a screw in. I did the same thing on the opposite end of the panel. The first two holes are difficult, but the rest line up pretty easily after that. Every day was full of those little problem solving challenges.