Updated on May 4th, 2025
Campervan insulation is one of, if not the, most important step. Have you ever gotten in your car on a 75-degree day only to find that the interior is 95? Or have you had to scrap the ice from the inside of your windshield? Of course! Cars, or vans, are very poorly insulated against the elements. To make a metal box a comfortable home, we have to do a lot to insulate it from temperature extremes.
Plan First!
For us, this started with mapping out our interior layout. We needed to know where all of the electrical and plumbing would be on and in the walls, as well as where the cabinets would be. Laying this all out before we insulated allowed us to run conduit where needed before we blasted some of the ribs with spray foam.
Choosing Between Campervan Insulation Options
Once we had our layout confirmed, we could start putting up insulation panels on the walls and ceiling. Remember, we already insulated the floor before we laid the subfloor on top! There are several other options out there for campervan insulation, and they all have pros and cons:
For this van, we decided to go with a combination of a few options. We used extruded polystyrene on the floor because of its great compression strength. We used expanded polystyrene foam on the walls and ceiling because our Home Depot was out of 1-inch XPS. But, it turned out to work very well because of the EPS’s flexibility.
We used spray foam in a few ribs where we knew we wouldn’t run wire, and we filled the rest of the ribs with Thinsulate. We also used spray foam in gaps around the EPS panels. In the rear and slider door we used Thinsulate as it wouldn’t obstruct any door mechanisms.
Choosing your insulation can be daunting but every van is different and everyone uses their van differently so thinking about your build, the locations you will travel, and your budget is a great place to start.
Campervan Insulation Installation Tips
Spray Foam Can Be Used as an Adhesive
In our first campervan, we struggled to use spray foam as an adhesive, but we are redacting that statement. Spray foam can be used as an adhesive for foam panels and a good one at that, but it does require some patience, and you’ll need to brace the panels for about 24 hours while the foam cures.
As Tempting as it is, Don’t “Snap” Foam Panels
A sharp box cutter or razor is your best tool for cutting foam panels. I know it can be tempting to score and snap, but you are way more likely to end up with jagged edges or run perfectly good foam. Scoring and breaking the panels is fine for very short cuts but learn from our costly mistakes on this one!
Wear Protective Clothing
Spray foam is permanent. It will not wash out of clothes or hair. It will not wash off your skin. A Tyvek suit is a great idea or you can go Andy’s route with a ratty old hoodie, gloves, and some painter’s tape. He has ended up with more than one haircut because he ended up with spray foam in his hair.
Use Smooth Cuts for Trimming
You don’t want to saw at foam panels or spray foam, as this will create a huge mess. Your best bet is slow, smooth cuts with a very sharp knife.
Real-Life Results
As I finish writing this post, the thermostat in the van says 75.6F, while the outside temperature is 18 degrees and snowing. The insulation we chose has kept us cool during 95-degree days and warm in temps as low as 5F. We have certainly put it to the test in the last few months and we are extremely happy with the job it’s doing!
Tools for Campervan Insulation
- Utility Knife: Andy likes the Harbor Freight version but this one is good too!
- Tyvek Suits: Make sure it has a hood!!
Budget Breakdown
Previous Costs ($14,874.16) include the floor insulation.
Note: All costs are as of April/May 2024
- 5 Sheets of 1″ Expanded Polystyrene Foam: $112.40
- 5’x10′ of Thinsulate: $100.00
- 8 Can of Spray Foam: $43.92
New Costs: $256.32
TOTAL COST: $15,130.48
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