How to properly insulate a van might be the most debated topic on the internet. I have read many different perspectives: some offer great advice while others are filled with BS. Below, I will share how I insulate vans and why.
My credentials? Over the last 4 years, I’ve van camped in temps ranging from -10 to 110 and came out just fine. Of course, if you are a powder hound and will be chasing winter storms, you will want to go above and beyond (or at the very least get a nice heater).
Step 0: We’ll get things started with an optional step, sound deadening. A lot of people make this seem like it’s super important, and it does help reduce road noise created by your van. However, once your build is finished, hearing only the noise of the van would be a godsend. Most of the noise you will hear will be created by all the things you put inside the van i,e,. silverware, oven racks, cooktop, and things bouncing and sliding around. So for this step, follow your heart. If you do want to sound deaden your van, this is a good product:
Click on the photos for more product information.
Step 1: Wall prep.
Wall insulation is highly dependent on how you plan to build your walls. There are 2 basic strategies and no right answer.
Option 1 is to fur out the walls so they plane evenly with the rest of the wall.
Pros: you get a flat wall with clean corners which make the rest of the build easier.
Cons: you loose a few valuable inches.
Option 2 is to curve the walls around the proud beams.
Pros: This approach maximizes space.
Cons: However, it makes the build (particularly cabinets) more challenging.
My preferred layout requires sleeping sideways, so every inch matters. Because of that, I take the more difficult path and build around the curves. Either way, start by furring out the more recessed vertical van supports. I use 2x3’s and metal-tapping screws.
Pro tip: Make sure to size your screws properly so you don’t drill holes to the outside!
Step 2/3: Pick up your insulation product(s). A good way to start insulating is by covering everything in reflective bubble foil secured by foil tape. When installed properly with air gaps on both sides, the reflective foil is a very efficient insulator. If it’s squished between other materials it is basically useless, so I consider this step optional as well.
Once you have installed (or skipped) the reflective foil, follow up using rigid foam board; I use 2” thick on the walls and 1” on the ceiling and secure it with spray foam. I like the foam board because it has the highest R-value per inch of material. Cut it to size and position in wall recesses using an adhesive or scrap wood prop. The 6 ft 2x3’s I use to support the bed work great for propping up foam board on the ceiling (pictured above). Leave about a half inch gap on all sides and fill the gaps with spray foam. (video coming).
Pro Tip: Try to make an air-tight seal around the foam board using spray foam. This will create dead space between the foam board and wall of the van and help insulate. Pick up foam board and spray foam (branded Great Stuff) at your local hardware store. You will probably need 6-12, 12 oz cans of Great Stuff depending on your efficiency. Some stores sell 16 or 20 oz cans.
Also, reflective foil is much cheaper online:
Step 4: Fill the beams.
Fill the smaller beams with spray foam. When it comes to bigger beams like the vertical one in the rear corners, I use un-faced fiberglass insulation (the pink cotton-candy stuff). Wear gloves and long sleeves to avoid irritating your skin while handling fiberglas insulation. Some people worry about this material getting moldy. It is not organic and won’t mold on its own but it can collect sawdust during the build process, which can support mold. I think the jury is still out on this one. If you are in a moldy area, maybe look for alternatives (and let me know if you find a good one) or buy extra spray foam. I spend most of my time traveling up and down the American west and I’ve never had any mold issues. Ask me again in 10 years.
Step 5: Insulate doors. Most of the doors are perfect for ridged foam board and spray foam. Some doors have moving wires and things to make the door open, close, lock, etc. In those areas the spray foam and foam board won’t work. I use the pink fiberglass stuff for these areas as it allows the moving parts to move. Lastly, I stuff the fiberglass insulation in any and all nooks and crannies.
Floor insulation will be covered in the Flooring section.