Insulating your van will be one of the first things you do in your build and it is a VERY important step in the process!
There is a vast range of options that you can use to insulate your van ranging from cheap DIY to high dollar hiring a professional. This post goes over 5 of the different insulation options available (there are more) but it will provide you with one from each price category.
When considering how you want to insulate your van, the first question you need to answer is where are you primarily going to spend your time? Will you be chasing the fair and warm weather all year long or do you plan to spend time in cold climates? And even if you plan to stay in warm weather, the evenings get chilly to near freezing in arid/dry climates. Another thing to consider is if you will be traveling with a pet. Pets do not regulate temperature the same as humans, so keep them in mind when deciding too. It is important to note that adding insulation later will be extremely difficult or impossible so spend some serious time considering your options.
An important thing to know when looking at insulation is what the heck an R-value is. An R-value is a measure of how well the insulation works at inhibiting heat transfer (heat coming into cold spaces or cold coming into warm spaces). All R values listed here are for an inch of thickness (except for Reflectix and Thinsulate).
Let’s dive into the options!
There is a vast range of options that you can use to insulate your van ranging from cheap DIY to high dollar hiring a professional. The list below is only a sampling of options available, but it will provide you with one from each price category.
- What is it: Everyone under the sun will reference Reflectix. It is basically bubble wrap with tin foil on the outside and it is by far the cheapest option. Its primary purpose is truly to be a vapor and radiant heat barrier and it does not insulate well on its own.
- How to use: For Reflectix to work properly, it needs to have an air gap between it and metal exterior walls. If you don’t want to leave an air gap, additional insulation also can be used to form this gap. Secure edges of the Reflectix with Foil Tape.
- R-Value: 1.1 (for a single layer)
- Cost: $88 per 48”x50’ roll (smaller sizes available)
- Where to buy: Hardware stores or Amazon.
- Important Notes: You will need to use Foil Tape around all holes or gaps in the Reflectix sheets to create a good vapor barrier. Do not use this as your only form of insulation!! It works best when combined with other options listed here.
2. Foam Board
- What is it: There are a few different kinds of foam board you will see at your local hardware store: XPS (Expanded polystyrene), EPS (Extruded polystyrene), and Polyiso (polyisocyanurate).
- XPS will be a white board and if you look closely it will look like a lot of tiny white Styrofoam balls compacted together.
- EPS is either the pink or blue in color.
- Polyiso has a white or yellow core, with foil backing on both sides. Because of the foil this also acts as radiant barrier.
- How to Use: Cut to size to fit the gaps and spaces in your van you wish to insulate and attach with a specific Foam Board Adhesive. If you use other forms of adhesive it will eat away at the foam board.
- XPS: 3.5-4
- EPS: 4.5-5
- Polyiso: 7-8
- Cost (4x8’ sheets):
- XPS: $19.55
- EPS: $16.28
- Polyiso: $20.98
- Where to buy: Hardware stores
- Important Notes:
- Polyiso is a closed cell foam filled with HCFCs or CFCs = off gassing, not good in small spaces. Also not good for environment.
- What is it: Sheep fur 🐑
- How to use: For Small
spaces/crevices: Cut into pieces to shove into small spaces. For large spaces, cut to size and attach with a spray adhesive.
- R-Value: 3.5-4
- Cost: $120 per 24lb bag
- Where to buy: Hardware stores or special order from online stores.
- Important Notes:
- It is absorbent but it will also emit moisture.
- Because it is thicker, it can also act as a sound barrier.
4. Thinsulate SM600L
- What is it: The white layer is a blend of polypropylene and polyester (plastic) materials and the black layer is a solid polypropylene, which is the vapor barrier. Thinsulate is used in a lot of warm technical outdoor clothing.
- How to use: For small spaces/crevices: Cut into pieces to shove into small spaces. For large spaces, cut to size and attach with a spray adhesive. See our post on insulation for more detail.
- R-Value: 5.2
- Cost: $120 - $415 depending on roll size
- Where to buy: Order online from The Swivel Shop or Amazon
- Important Notes: FMVSS302 Certified – fire-resistant (Federal Motor Vehicle Safety Standard). It is a hydrophobic material, meaning it does not absorb moisture. It can easily be done in sections as needed while using the van.
5. Spray Foam
- What is it: Foam that is wet when sprayed and then expands to form a hard dry foam.
- How to use: Take necessary precautions to adequately prep and protect your van for application. Apply using a sprayer and get the foam into the cracks and crevices of the van as well as large spaces. Will need to be cut and trimmed at the end.
- Please research this extensively if you plan to do it yourself instead of hiring a professional
- R-Value: 6
- Cost: $770 for the kit
- Where to buy: Hardware stores have kits or hire a professional.
- Important Notes:
- It is a very messy process.
- The entire van needs to be done at once, whether you hire a professional or do it yourself
- If you choose to do it yourself, there are a few kits out there but be warned there is a learning curve for spray form and knowing how much to spray so it expands correctly.
- Very Permanent, hard to do wiring in cavities after the fact
The Insulation We Used in Our Build
For our build, we knew we were not planning to just chase warm weather so we needed to keep the van toasty in the winter and tolerable in the summer heat. To be able to keep the van warm in the winter, we needed a high R-value. Even though spray foam has the highest R-Value, we decided not to use it because we were using the van as we were building it. From our remaining options, we decided to go with a combination of three different materials: Thinsulate, EPS Foam Board, and Reflectix.
We used the EPS on our floors and then Thinsulate and Reflectix on the walls and ceiling. We estimate that we were able to achieve R7.5 for the floors and R8.0 for walls and ceiling. All of our insulating materials came to around $1,000 which seems like a lot of money to put into part of the van you will never see. However, on those cold nights or when your van is tolerable until 2 pm in the mid-summer heat, you will thank “past you” for putting in some time and money to properly insulate your van early on.
For more van related content checkout out out website Stokeloafvan