Adding Insulation and Sound Proofing to our Sprinter Van

Taylor and I recently bought a 2015 Mercedes 170” Cargo Sprinter Van, with plans to convert it into a home on wheels. Our goal is to take this van all over North America eventually reaching Alaska. To help inspire others, we are documenting our journey and each step of our van build, creating video tutorials on youtube along the way.

Van insulation is the 10th episode of our van build series, which covers how we insulated our sprinter van (this could apply to a transit, Promaster, or another vehicle as well). We will primarily drive the van in the summer on the “road to Alaska” journey, but we wanted to insulate the van so we are not limited to warm weather. Besides as we travel north we can still find ourselves in some colder weather in the summer!

Now, I know insulation is a controversial topic in the van life community and this blog post does not discuss the best insulation type to use in a van. Instead, this post documents what insulation types are available and what we used and why.


How we insulated and sound proofed our van
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Types of Insulation for a Van

After doing some research we found that there are four main types of insulation to choose from.

  • Loose-fill (Spray foam) insulation
  • Foam board insulation
  • Insulation batts or insulation rolls
  • Vapor Barrier

Spray Foam

Spray foam insulation is exactly what it sounds like and can get applied via a spray can, like “Great Stuff”, or professionally done via a spray gun with an air compressor. This is a more permanent solution as it’s very difficult to remove and nearly impossible to remove from small cavities like the frame ribs of a van.

However, this could be something to consider if you want someone else to insulate your vehicle at a relatively cost-effective way. You will likely be able to cover the walls, ceiling, and floor with it in one shot when you get this done to your vehicle.

Foam Board

Although rigid foam board insulation isn’t the most pliable insulation type available, it is one of the most efficient insulation types available. When I say most efficient, I mean, it has the highest R-value for the least amount of mass per inch. There are different sizes (thicknesses) of rigid foam board, providing different r-values depending on the thickness.

We used 1″ thick foam board throughout our van covering the ceiling and the window frames, which has an R-value of 6.0.

We were thinking about putting this on the floor but due to my height (6’1″) it would reduce the available headspace in the van, ultimately making me bend my head. This was a big no-no for me and we decided not to install it on the floor.

Insulation Batts and Insulation Rolls

Insulation batts or insulation rolls come in different shapes and types. Some different types include:

  • Fiberglass
  • Mineral wool
  • Denim
  • Insulate
  • Havelock (sheeps) wool

In addition to the ones listed above, I am sure there are other less popular types as well which have their own pros and cons. Most of these products are sized for studs in homes, between 16 and 24 inches, but you can use them for your van.

At the end of the day, you need to do your research to decide which insulation types is best for you.

What did we choose?

We chose mineral wool because we wanted to reduce the amount of moisture in our van. Not only is mineral wool moisture resistant, but it is fire resistant as well, which was important to us. Taking that into consideration it is relatively inexpensive compared to insulate or havelock wool so we decided to go for it.

We stayed away from fiberglass due to the harmful effects on the body and decided to go against denim since it’s not water-resistant.

So this in addition to rigid foam board was the right choice for us. We knew rigid foam board wouldn’t fit in the tight cavities of the van’s frame so we used the mineral wool for that.

Vapor Barrier

A vapor barrier helps keep moisture away from your insulation, which in turn helps prevent mold and rotting. Lots of folks have mixed feelings on vapor barriers and say it’s ineffective.

I am certainly not an expert and respect everyone’s opinion so again this is an area where you should try to get an expert opinion. In my opinion, if you use fiberglass or denim insulation then you want to create a vapor barrier since if fiberglass or denim is not water-resistant. If you’re using other materials like wool, insulate, spray foam or rigid foam board, then you’re likely ok without one.

In our build, we did decide to use a vapor barrier, using reflectix and reflectix tape.


Tools needed to insulate and soundproof a van

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Below are some of the products we used to insulate our van. We used Rockwoll insulation with an R-23. For our vapor barrier, we used reflectix and reflectix tape. If you decide to build a vapor barrier, buy the big roll of tape, you will need it! For soundproofing, we used rattletrap, which is one of the most popular brands available.


Video – Adding Insulation and Sound Proofing

If you prefer videos over reading then check out our video where we documented how we applied soundproofing and insulation to our van.


Adding Sound Proofing to our van

Since it’s our first van build we can’t really claim whether or not soundproofing a van is an absolute must do. When we bought it our 2015 Mercedes Sprinter 170″ wheelbase, it already had some soundproofing material installed by the manufacturer.

However, we decided to add more and used Rattletrap sound deadening adhesive fatmat anyway since we figured it can’t hurt. We added it to the areas of the van that did not have any of the manufacturer’s sound deading material including the walls, ceiling, and wheel wells.

Adding rattletrap sound deadening adhesive to our van
You can see the yellow soundproofing adhesive in the van, that’s the manufacturer’s

Rattletrap is apparently one of the best manufacturers of sound deadening adhesive mats and they make it easy to install it to your van.

Pro Tip: When using rattletrap, leave it in the sun to warm it up so it’s more pliable. Also, use the roller they provide to ensure there are no air bubbles!

Adding insulation to our van

Like I previously mentioned, we used a mix of different insulation materials for our van. Below are the steps taken to get our van insulated and ready for the next part of our build.

First: Rigid Foam Board Insulation

The first thing we did was add rigid foam board insulation to the window frames of the van. We did this using a combination of spray adhesive as well as spray foam around the edges to secure it in place.

using spray foam to stick our rigid foam insulation board to our sprinter van

We also used rigid foam board insulation for the ceiling as well. This was actually the easiest way to insulate the ceiling. We cut the foam board to match the width between the ribs of the ceiling and then pressed the foam board between the ribs having enough tension to secure it in place. We also used spray foam again to add more support as well as spray adhesive.

rigid foam board on the ceiling of our van

Second: Mineral Wool Insulation

Once the rigid foam insulation boards were in place and secured with the spray foam, we moved on to stuffing the cavities of the van with mineral wool.

Adding rigid foam board insulation to our sprinter van
Taylor adding wool insulation into the cavities of the van.

You will be surprised how much space there is in the open cavities of the van. We use screwdrivers and clothes hangers to help wedge as much insulation as deep as possible into some of the channels.

a look at our van with foam board and mineral wool insulation in our sprinter van

Don’t forget to insulate over the headboard! We added some reflectix and miner wool insulation over our headboard to ensure the entire van was well insulated.

Lowering the headliner to add insulation to headboard of van

In total, we used 2 large bags of R-23 Rockwool mineral wool insulation. It took several hours to complete and we went through several sets of rubber gloves! But we can officially say we insulated almost every inch of the van!

Third: Reflectix Vapor Barrier

After we cover the van in rigid foam board and mineral wool insulation, we use reflectix to create a vapor barrier sealing up the van. We used the 48″x10′ roll of reflectix to cover a majority of the wall and then use reflectix tape to seal it up.

We apply this to the ceilings and walls.

Van insulation with reflectix vapor barrier

Van Floor Insulation

We used reflectix on the floor of our van, which I probably wouldn’t do again. Like I previously mentioned, due to my height we’re very limited on what we could use for insulation, but I could have gone with .5″ inch foam but I heard it’s really soft and makes your floor feel like a sponge board.

If I did have enough space, (if the van height was taller or I was smaller) I would use 1″ thick foam board with plywood over that. I think that would give you the best insulation possible.

Summary

When building out a van, insulation is an absolute must-do, especially if you plan on doing any traveling in the winter months. Like I mentioned above, it’s important to do your research and determine what insulation type is best for you. There are several different types out there to choose and it can get overwhelming. Everyone has their own opinion and you should too!

Head back to our main van build page to see more progress of our build. If you want to jump to a specific build project, here are a few listed below.

Other Van Build Posts:

If you have any questions or have a recommendation on how you would insulate your van, please share below!

About The Author

Kevin Mathers

A washed-up hockey player, surfer, and husband currently working towards financial freedom and showing you how we do it as a couple. I started this blog initially as a personal finance blog but after getting married, Taylor (my wife and best friend) and I decided to switch gears into the travel world sharing our experiences with you along the way.

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