Is Thinsulate Van Insulation Good for a Van Conversion? Pros & Cons, Honest Review

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Insulation is a crucial aspect of any van conversion project. Without it, the van will be too cold, too hot, too loud, or too moist. One of the most popular options is 3M’s Thinsulate van insulation. It has gained popularity for its affordability, easy installation, and thermal and sound insulating properties, but does it really hold up to the tests of life on the road?

After 5 years of full-time van life, I know firsthand how the right insulation can make or break your van build, creating a cozy climate-controlled interior, or a musty, mold-infested, cold metal box. I also know people who have lived for years in amazing Thinsulate-insulated vans! In this comprehensive review, we’ll take an in-depth look at Thinsulate as a van insulation, examining its effectiveness, R-value, and whether it’s a good choice for your conversion.

Quick Review: Thinsulate is Lightweight, Thin, Sound Deadening, and Quick Install

Let’s cut to the chase: if thin walls, maximum ceiling space, easy installation, and a quiet ride are most important to you, Thinsulate Van Insulation by 3M is an awesome choice. This lightweight, efficient insulation has thermal and sound-dampening properties. It has an R-value of around 5.2, making it a moderate insulator compared to other options. You don’t need to use a sound deadener and it is one of the thinnest, most lightweight options for maximizing interior space and reducing van payload weight.

While it excels at moderate climate control, reducing road noise, and easy installation, it comes with a higher price point and less insulating capacity for extreme temperatures. Thinsulate is not recommended for subfloors due to its low R-value and lack of structural support. Overall, it’s a reliable choice for van insulation, but you should carefully consider your budget and specific needs before choosing it for your project.

It’s best to be patient maneuvering insulation into nooks and crannies

Is Thinsulate Van Insulation Good?

Thinsulate by 3M is a solid choice for a DIY van conversion. This 3-layer insulating material is among the most common and popular van insulation materials because it is specifically designed for vehicles. It’s known for its lightweight yet efficient insulation capabilities, making it an excellent option for those looking to maintain comfortable temperatures inside their van while minimizing weight and bulk. 

Thinsulate’s effectiveness extends to both thermal and acoustic sound insulation, addressing both temperature and road noise. Although it doesn’t have the highest R-value, it is extremely lightweight and easily fits in any shape or cavity of the van.

Here are some key points that highlight why Thinsulate van insulation is a good choice:

  • Sound Deadening: If you don’t want to add extra sound deadener, Thinsulate offers an all-in-one option that protects against cold, heat, and noise.
  • Easy to Install: The 60 inch wide rolls are super easy to cut and install with 3M spray adhesive. Simply spray and stick! The ceiling is easiest with two people.
  • Moisture Management: The naturally hydrophobic material won’t trap or absorb moisture, which prevents condensation and mold in the walls of your van. 
  • Durability: 3M designed Thinsulate SM600L specifically for vehicles, so it can easily withstand the rattling and constant motion of a van. It won’t sag or fall out of place.
  • R-Value: At just 1 ¾” thick, the 5.2 R-value is pretty substantial. It’s not as high as spray foam or sheep wool, but I’ve met many van lifers who spend their winters in the mountains inside warm Thinsulate-insulated vans.
  • Made for Vehicles: Thinsulate is FMVSS 302 certified, which means it meets the federal motor vehicle safety standard. In other words, this material is specifically made for moving vehicles, while many other insulations are designed for homes.

What is the R-Value of 3M Thinsulate Van Insulation?

3M thinsulate has an R-value around 5.2. The R-value of insulation materials is a measure of their thermal resistance. A higher R-value indicates better insulation properties. 

For a thickness of 1 ¾” (44mm), 5.2 is a moderate R-value. If you compare the same thickness with other insulations:

  • Closed-cell spray foam has an R-value of 12.25 (or 7 per inch)
  • Polyiso foam board is 11 (or 6.5 per inch)
  • EXP foam board is around 10 (or 6 per inch)
  • Sheep wool insulation is 6.65 (or 3.8 per inch)

So Thinsulate isn’t the highest R-value insulation option, but it has many other benefits. This lofty non-woven fibrous material is the premium choice for insulating van walls, ceilings, and cavities where you want to take up the least amount of cabin space.

Thinsulate Van Insulation: Honest Product Review

Based on all the van lifers I’ve met on the road, Thinsulate is a proven reliable option for insulating the ceiling, walls, and overhead cavity above the driver seat. It truly moderates the temperature, saves a lot of space, and cuts down on weight. It also deals with moisture fairly well. 

However, I wouldn’t recommend it for the floor because it isn’t very structural and doesn’t have the highest R-value. I would only use Thinsulate in your van subfloor if you are tall and really short on vertical space. Otherwise, a wood subfloor with foam or sheep wool in between is ideal. 

Here are the pros and cons of 3M’s popular product:


  1. Thermal Insulation: Thinsulate excels in maintaining a comfortable interior temperature inside your van. Whether you’re facing scorching summer heat or freezing winter cold, Thinsulate helps regulate the temperature, reducing the need for additional heating or cooling systems.
  2. Sound Insulation: Beyond its thermal properties, Thinsulate is highly effective at sound insulation. You don’t need to use sound deadener thanks to the interwoven synthetic fibers that trap and dampen sound vibrations. It significantly reduces external noise, creating a quieter and more peaceful environment inside your van.
  3. Lightweight and Space-Efficient: Thinsulate stands out for its lightweight nature. Unlike some bulkier insulation materials, it doesn’t add excessive weight to your van, which can be critical if you’re concerned about your van’s payload capacity. Additionally, the compressed material expands to a thin 1.75”, allowing you to maximize interior space.
  4. Ease of Installation: Thinsulate is relatively easy to install behind your walls using spray adhesive and extra sharp scissors. This DIY option is quick and beginner-friendly.
  5. Durability: Thinsulate is known for its durability and resilience. Unlike most insulations, it’s designed for a moving vehicle. I know people who sleep in subzero temperatures in a van with Thinsulate and a diesel heater.
  6. Moisture Management: The fluffy synthetic fibers are naturally hydrophobic, meaning they won’t absorb moisture. Thinsulate helps prevent condensation behind your van walls and is completely resistant to mold or mildew.
  7. Odor Free: Thinsulate is neutral in smell and won’t give you a headache from chemical fumes. However, the spray adhesive you choose may cause issues with sensitive people.
Get help from a friend during installation


While Thinsulate Van Insulation offers numerous advantages, there are still some drawbacks to consider, like the expense, low R-value, and synthetic composition.  

  1. Low R-Value: 3M Thinsulate does not have a very high R-value compared to other options. The R-value comes out to just 3 per inch, which is less than half of spray foam, foam board, or sheep wool insulation.
  2. Not Great for Subfloors: This flexible, fabric-like material is not ideal for a subfloor because it has a low R-value and non-weight-bearing design. You lose the most cold and heat through your floor and windows. You may want a more rigid, dense insulation with a higher R-value for the floor.
  3. High Price Point: Thinsulate is a premium product that can cost $700 to $1,000 to insulate an entire van. It is not as budget-friendly as foam board, denim insulation, or Polyiso.
  4. Synthetic Material: Although it is fairly non-toxic, Thinsulate is still synthetic and not an eco-friendly option. You will have to use some sort of adhesive or double-sided tape to apply it, which could contribute to chemical or health concerns. 

Alternatives to Thinsulate Van Insulation

If Thinsulate doesn’t seem to have the insulation power you need, consider these popular time-tested alternatives:

1. Highest R-Value: Spray Foam

Spray foam is a highly popular option in tiny homes on wheels because it seals every crack and can have an R-value of up to 6.5 per inch! This is by far the highest R-value available. Better yet, spray foam easily fills awkward-shaped crevices and is impermeable to water vapor. The only problems I’ve seen people face are:

  • Difficult and messy installation (requires special gear or a contracted professional hire)
  • Offgassing and potential toxins
  • Low breathability or airflow

That being said, spray foam is the insulation of choice for many of my full-time van lifer friends who travel between a huge range of climates, from Alaska to Baja Mexico! The spray foam adheres to the van and holds up to years of rattling and changing conditions.

Foam board can be used to insulate the garage space

2. Most Widely Available: Rigid Foam Board

If you want insulation that you can buy at any hardware store, foam board is the simplest option. There are many types of rigid foam, from Polyiso to pink Owens Corning FOAMULAR, but they all provide similar benefits. An R-value of 6.0 per inch is standard, and the foam boards are available in varying thicknesses. 

The main drawback is the inflexibility; you can’t put foam board in those weird crevices or curves. This is a great affordable option for your subfloor or walls, but not so great for your ceiling, doors, or over the cab.

3. Most Natural and Non-Toxic: Sheep Wool Insulation

If you are an earthy van dweller, sheep wool (NOT rock wool) is the most natural option on the market. This insulation is made of pure wool without any adhesives or additives. It is naturally breathable, mold-resistant, pest-repellant, temperature-controlling, sound-deadening, and fire-resistant. Most sheep wool insulations are treated with a small amount of all-natural boric acid to prevent any pest problems. 

This is what I used in both my school bus and my van, and it has been absolutely amazing. I’ve never had an issue and I stay extremely warm in the mountains and super cool in the Florida heat. Companies like Havelock Wool offer bats specifically designed for vans so your DIY install is easy and toxin-free.

Key Takeaways: Thinsulate is Easy to Install and Holds Up to the Road

Ultimately, Thinsulate’s pros outweigh its cons in my book. If I wanted to put together a quick and easy DIY conversion, this is the material I would use. It allows you to skip the sound deadener and literally just spray-and-stick it in place. It’s also easy to stuff into weird-shaped cavities like the doors and the area above the driver’s seat.

However, if you plan for more extreme climate adventures, opt for something with a higher R-value like spray foam, or more natural breathability like sheep wool. Or you could combine Thinsulate with an epic affordable diesel heater

See you out on the road!

Photo of author


Logan Hailey is a writer, natural wellness educator, and full-time van lifer. A nomad at heart, she has lived on the road for 5 years and counting, first in a DIY skoolie and now in her self-converted Sprinter van. She is passionate about living in harmony with nature and creating off-grid van vessels to enjoy the beauty of wild places. Keep up with her adventures on Instagram (@naturallylogan), TikTok, and YouTube.

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