Camper Van Insulation: The Ultimate (Stay Warm!) Guide

We get it; insulating a camper van is boring! It’s a lot of effort to insulate your van, but all that work eventually gets hidden behind the walls and ceiling, never to be seen again. But living in a camper van in extreme climates is uncomfortable and, sometimes, downright dangerous. In this article, we share everything you need to know about insulating a camper van and all the van insulation materials available to you.

So, if you’re ready, let’s get started!

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Why Is Insulating Your Camper Van Important?

Before and after image showing an empty commercial van interior and a finished camper van conversion
Before and after comparison of our van conversion

When we first purchased our Ford Transit, our brand-new commercial van was simply an empty metal shell. And when our new van was parked throughout the day, we noticed that the inside temperature would fluctuate quickly to either extreme. Under direct sunlight, the van’s sheet metal became almost too hot to touch, and sitting in the van felt like we were baking inside an oven. At night, the van’s internal temperature dropped quickly and drastically without any way to prevent the warm air from escaping.

So insulating your van is essential for the following two reasons:

  • Temperature Control – By insulating a camper van with the proper materials, we can muffle drastic temperature swings and keep our van warm during the cold months and cool during the hot summer months. Trust us, van life isn’t fun when you’re stuck in a cold camper van for hours. (But even with great insulation, we still recommend installing a camper van heating solution for those frigid days)
  • Noise Reduction – A great side benefit of adding insulation to your van conversion is that noise from outside the van is muffled. This is especially useful when parked overnight in loud public areas like Walmarts and truck gas stations.

So, although properly insulating the van may not be the most Instagram-worthy part of a van conversion, it’s a crucial step to properly finish for anyone wanting to live and travel long-term in their vehicle.

Camper Van Insulation Theory

Although the purpose of this article is not to go into heat transfer science, it is essential to learn the basics of insulation theory to understand why insulating your van is important and how to insulate it effectively.

How Heat Enters (and Escapes!) Your Camper Van

Most heat enters a van through either “radiation” or “convection.”

“Radiation” is when heat is transferred through air. In a van, radiation heating occurs most frequently when a sun’s rays pass through the windows and heat the van. Stick your hand next to a window on a sunny day and feel how hot it feels.

“Convection” is when heat is transferred through a solid surface, like metal. In a van, convection heating occurs most frequently when the sun’s rays hit the van and heat the van’s metal frame. The heat from the van’s metal frame is then transferred to the van’s interior space, thus heating the inside.

Conversely, heat escapes your van when it’s cold outside and warm in your camper van through radiation and convection. This cools your van and brings its internal temperature closer to the temperature outside.

The Importance of “R-Value”

All formal insulation materials are rated in terms of their “R-value,” which is the material’s ability to resist heat flow. Long story short, the higher a material’s R-value, the better its insulative properties. A material’s R-value is usually listed as a per unit length (usually ‘per inch’ in the USA).

When we assess the usefulness of an insulation material when used in a camper van conversion, one of the most important measurements we use is the ‘per inch’ R-value.

Example: The “R-value/per Inch” of Polyiso Foam Board is 6.0, whereas it is only 5.0 for XPS Foam Board. Therefore, you could conclude that the Polyiso Foam Board provides better heat insulation than the XPS Foam Board.

What To Look For When Selecting Insulation Materials

Many different types of insulation materials can be used when converting a camper van. From stiff foam boards to soft spray foam, reflective bubble wrap, and even sheep’s wool. And no two people’s vans use exactly the same mix of insulation materials. However, because of the unique nature of camper van living (i.e., small living space, exposure to high moisture environments, and tight conversion budget), we’ve learned that some insulation materials are more useful and practical than others.

Here is what to look for when selecting camper van insulation materials.

  • High R-value per inch – Because the internal space of a van is quite limited, we need to find insulation materials that provide maximum heat insulation but take up the least amount of space. Essentially, we will look for materials with a high R-value per inch.
  • Mold Resistance – Whether at the beach, camping in humid environments, or waiting out a torrential rainstorm, your van will be exposed to moisture. If the moisture doesn’t dry off soon, mold tends to form behind the camper van’s walls and ceiling. Therefore, selecting mold-resistant insulation materials is essential.
  • Non-Toxic – Most insulation materials pass this test. Still, there are several materials out there that don’t provide the safest environment for living in, especially in a tiny space like a van.

Areas To Insulate in Your Camper Van

When you’re standing inside your empty van, thinking about how to tackle your camper van insulation project, the whole thing can feel daunting. After all, the inside of an empty van can feel quite big and empty! But when you tackle each different part of the van separately, insulating the entire van feels much more doable.

Below are the five parts of the van worth insulating. For each of the below parts of the van, we also recommend which insulation materials are worth using.

  • Walls – The sheet metal walls of a van receive a ton of sunlight and are one of the primary reasons why the interior temperature of a bare metal van fluctuates so much. Insulating the walls of your camper van should be one of the biggest priorities.
  • Ceiling – Just like with the walls, the van’s metal ceiling absorbs a lot of sunlight and dissipates the heat inside the van. Therefore, insulating the camper van’s ceiling is also a high priority.
  • Floor – Whether or not to insulate the van’s floor is a contentious topic. Unwanted heat does not enter the van through the floor, but the cold does come from below. Some believe every bit of insulation helps, and others believe insulating the floor is not worth the loss of interior height. We are with the former and believe the floor is worth insulating.
  • Windows – If you have windows in the back of your van, it’s important to have something to insulate the windows with to prevent unwanted heat from entering and exiting the van. It is often an afterthought, but insulating the windshield can be just as important. On a sunny day, the van’s cab can get hot!
  • Separating The Cab From The Living Quarters – Because the front of the van (the ‘cab’) is surrounded by large windows (i.e., the windshield and side windows), the cab can get brutally hot and cold throughout the day and night. Warm and cold air in the cab can easily transfer to the rear living quarters of the camper van and affect temperatures there. For this reason, it’s essential to have an insulation barrier between the cab and the van’s rear living area.

Common Camper Van Insulation Materials

Below is a list of 6 camper van insulation materials we recommend and use in our own van. We describe each material, where you can purchase them, and talk about the pros and cons of each material.

(Further below in this article, we also talk about several insulation materials that we DO NOT recommend and why.)

Sheep’s Wool Insulation

Sheep’s wool is fast becoming the camper van insulation material of choice for many van lifers. Wool is a renewable material, is non-toxic to produce and breathe in, and is just super cool to say that you use it!

We loved using sheep’s wool in our van insulation project for the following reasons:

  • Malleable – Sheep’s wool is great for stuffing into the large cavities all over your van. In our Ford Transit, there were huge air voids in the upper and lower edges of the van. And sheep’s wool was perfect for filling those voids.
  • Reduces Risk Of Mold Growth – By absorbing moisture and condensation, sheep’s wool helps keep your camper van dry and mold-free. Best of all, when wool absorbs moisture, the material does not lose its insulative properties. When ambient air dries out during the day, moisture is released from the wool back into the air without promoting mold or mildew growth.
  • Fantastic Noise Insulation – If you consider yourself a light sleeper, adding sheep’s wool can really help to dampen external noises. It can get loud overnight at Walmart, and truck stop gas stations.
  • Renewable Resource – No sheep were harmed in making this insulation material. We loved that sheep’s wool for camper van insulation is a sustainable and renewable resource.

Downsides of Sheep’s Wool

The major downside of using sheep’s wool in your van insulation project is that you’ll likely have to order it online. Sheep’s wool just isn’t available to purchase at most retail stores. We ordered our wool online from Havelock Wool. The purchase process was quick and simple and our order came within days of purchase.

If we could build a second van in the future, we would use sheep’s wool again when insulating our camper van without hesitation.

Polyisocyanurate Foam Boards (Polyiso)

Polyiso foam board
Common Polyiso foam board found at most big box hardware stores

Polyisocyanurate (Polyiso) foam boards are one of the most popular camper van insulation materials today. The material is sold as a stiff foam board sandwiched between two layers of foil on each side, giving the overall product an additional radiant heat barrier if installed with an air gap. 

These rigid foam boards are most often placed across the van walls and ceiling and, with a high R-value of 6.0, provide great insulation. Polyiso boards are also easy to cut and shape, with a blade, to appropriate sizes to fit the odd shapes inside a camper van. These boards should be a staple in any van conversion insulation project.

Polyiso Stats:

  • R-Value Per Inch: 6.0
  • Mold Resistant? Yes 
  • Toxicity: Completely non-toxic, safe for installation
  • Where To Buy: Home Depot and other major hardware store chains

Extruded Polystyrene (XPS)

XPS foam board
XPS foam board commonly found at most big box hardware stores

Extruded Polystyrene (XPS) foam board is similar to Polyiso but with three major differences.

  • Lower R-Value – At an R-Value of 5.0, XPS foam board is slightly less insulative than its Polyiso counterpart.
  • Higher Compression Strength – XPS foam boards have a much higher compression strength. You can actually walk on these boards without denting them, which makes XPS boards more suitable for insulating your van’s floor. Polyiso boards dent easily under pressure and should not be used on the floors.
  •  Color – XPS foam boards are almost predominantly bright pink in color.

XPS Foam Board Stats

  • R-Value Per Inch: 5.0
  • Mold Resistant? Yes
  • Toxicity: Non-toxic. However, HFCs are released into the atmosphere during manufacturing.
  • Where To Buy: Home Depot and other major hardware store chains

Spray Foam (Closed Cell)

We used lots of spray foam to insulate all the tiny gaps & cracks in our camper van. This was invaluable because there are actually lots of tiny air pockets all throughout the van’s frame that, when unfilled, provide an avenue for heat to transfer through, unknowingly. The ribs running across the ceiling of our van, for example, had numerous air pockets that we needed to fill with spray foam.

Great Stuff | Spray Foam

A useful insulation solution that helps you fill gaps and cracks in hard-to-reach areas. The straw allows precision placement, and the foam expands to ensure an airtight seal.

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In terms of insulation value, closed-cell spray foam has an excellent R-value of 7.0. This makes spray foam one of the most space-efficient, high-performing insulation materials for camper vans on the market.

One of the downsides of spray foam is that it comes in small canisters. We had to purchase quite a number of these cans to properly spray foam all the areas that we wanted in our van.

The second downside is that spray foam is messy! It’s important to wear latex gloves when extruding the foam from the can. If the wet foam gets on your hands, it takes 3-4 days to peel off properly. Take it from us!


Reflectix is another popular insulation material for camper vans because of its powerful ability to reflect radiant heat. The material is essentially bubble wrap sandwiched between a reflective coating on each side.

Reflectix | Bubble Insulation

Some van lifers love to hate on Reflectix, but we love the material because it's lightweight and thin. Reflectix is not our primary insulation material, but we tape it on our walls and ceiling as an additional insulation layer to support our foam boards.

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Because of the material’s ability to reflect radiant heat, Reflectix is often used as an insulation material for window coverings.

But we also used Reflectix as the final insulation layer on our walls and ceilings. This is because Reflectix works best when there is at least a ¾” air gap to allow the material to reflect the heat away properly. And when placed over our Polyiso foam boards, we had about a ~1” gap for the Reflectix to work properly.

Reflectix Insulation Stats

  • R-Value (when used properly): 4.4
  • Mold Resistant? Yes
  • Toxicity: Non-Toxic
  • Where To Buy: Home Depot or other major hardware stores

Duct Insulation

We didn’t see duct insulation being used too often in other van builds, but we used it as the initial insulation material on our van’s floor. We really liked using duct insulation because, on one side, there is a sticky substance that adheres firmly to the van’s sheet metal floor. And on the other side is a foil layer that doubles as a radiant heat barrier.

Frost King | Duct Insulation

Helps prevent cold air from rising through the floor into your van. Apply this self-adhesive foam and foil insulation directly onto your van's metal floor. Also acts as a sound deadener.

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It was cold when we would walk on the van’s metal floor with our bare feet. But after placing a layer of duct insulation on the van floor, we felt the floor was instantly warmer. This stuff works!

Duct Insulation Stats

  • R-Value: 3.0
  • Mold Resistant? Yes
  • Toxicity: Non-toxic
  • Where To Buy: Amazon

Blackout Curtains

Blackout curtains are a fantastic way to isolate and insulate the rear living quarters of a camper van from the front cab. As we discussed earlier, the front cab of the van can get both deathly hot and freezing cold because the area is surrounded by large windows (windshield and side windows). Attaching a curtain rod and installing a blackout curtain is a fantastic way to keep the drastic air temperatures isolated in the cab while keeping the temperature in the rear living area more stable.

100% Blackout Curtain

Perfect van life addition to separate front cab and rear living quarters. Curtains prevent light from reaching the sleeping area and provide an insulation layer during hot and cold weather.

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We know from experience that these curtains work wonders in blocking heat transfer between the two regions of our camper van.

And a bonus is that these curtains do a great job of blocking light from exiting the rear part of the van at night, increasing privacy and ‘stealthiness.’

Blackout Curtains Insulation Stats

  • R-Value: ~4.0
  • Mold Resistant? No
  • Toxicity: Non-Toxic

How We Insulated Our Van Conversion

In this section we discuss how we used the above seven insulation materials to insulate our camper van properly. We understand that everybody has their own camper van insulation strategy that works. But in our five years on the road (and counting!), we know that our van has been insulated very well.

We’ve parked up in frigid, high-altitude locations, and we could live comfortably in our van at night (although having a camper van heating solution) helps tremendously. And we’ve also camped out on sunny beaches but we were able to keep a cool internal ambient temperature during the day (having proper ventilation is essential).

Keep Reading! At the end of this article, we will also share two additional materials we used that, while not ‘technically’ considered insulation, have helped tremendously keep our van’s internal temperature more stable.

How To Insulate a Van Floor

Insulating the floor of our camper van was the first part of the van we worked on. The sheet metal floor of the van really radiates frigid cold air into the van’s interior. Plus, it’s super unpleasant to walk on with bare feet because it’s so cold!

First Layer

Adding duct insulation to the floor of our camper van
Applying duct insulation to the van floor

Our first step when insulating our camper van’s floor was to put a layer of duct insulation right on top of the metal floor. This was easy to do as it only involved cutting the duct insulation to the appropriate size and (with the putty-side down) adhering it to the metal. Immediately, the floor was no longer cold to the touch.

Second Layer

Adding insulation to our camper van
Adding XPS Foam Board To The Floor

The second step involved cutting XPS foam board and placing it on top of the duct insulation. We used XPS instead of Polyiso because XPS had a substantially greater compression strength, meaning that this foam board does not dent when walking on it, unlike Polyiso.

Third Layer

Two people standing inside a DIY camper van
Standing on our plywood subfloor

We then added a ⅓” plywood subfloor on top of the XPS. This plywood adds stability to the floor for when we live and walk around inside our van. Before installing, we sprayed the plywood with a  mold-prevention formula and painted a layer of mold-killing primer.

The Final Step

Next, we used a can of Great Stuff spray foam and sprayed it around the edges of the floor. This will prevent hot and cold air from seeping around the sides of the van’s floor.

Finally, before adding our final luxury vinyl planks, we installed a layer of underlayment, which is essentially a thin styrofoam layer that acts as a final layer of heat, sound, and moisture insulation to the floor.

Underlayment with Moisture Barrier

Provides support for vinyl and laminate floorboards. Includes moisture-blocking film to prevent water from seeping down into the plywood subfloor.

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How To Insulate Camper Van Walls

Adding foam board insulation to the side of a camper van

When thinking about walls, I like to divide our van’s walls into three sections: the top, middle, and lower sections.

In the top and bottom sections of our Ford Transit van, there are huge cavities that take up lots of air space. We cannot cut these cavities out because they are essential to the stability of the van’s frame. Therefore, to insulate these upper and lower cavities, we stuffed in generous quantities of sheep’s wool.

In the middle section, we only have a thin piece of sheet metal separating the inside of the van to the outside. First, we placed a layer of Reflectix right across the sheet metal*.

Reflectix Note: Yes, we are aware that Reflectix supposedly only works with an air gap, but we find that Reflectix acts as a very decent ‘base layer’ when insulating camper van walls. It’s a thin material that does not affect a van’s internal living dimensions. Similar to wearing a thermal base layer when going on a hike.

On top of our Reflectix ‘base layer’, we attached our Polyiso foam boards to the Reflectix with a combination of spray glue and tape. We then used spray foam around the gaps, cracks, and edges to keep the Polyiso firmly in place.

Lastly, we put another layer of Reflectix over the Polyiso foam boards for a final layer of insulation. In this situation, there were plenty of areas with an appropriate air gap, so we’re confident that the insulating potential of Reflectix is maximized.

For more information about how we built our camper van walls, read: How To Build Strong Camper Van Walls

How To Insulate a Camper Van Ceiling

Polyiso foam board insulation added to the ceiling of a camper van
Adding Polyiso foam board to our van’s ceiling

Insulating a camper van’s ceiling is crucial because the van’s roof absorbs the brunt of the sun’s rays every day. It’s crucial to install a solid insulation layer to prevent the sheet metal roof from radiating heat throughout the van’s interior.

The process of insulating our van’s ceiling was similar to when we insulated our walls. First, we taped a Reflectix base layer across the van’s sheet metal roof. Next, we cut out pieces of Polyiso foam board and adhered them onto the reflectix with a combination of spray glue and tape. We then used spray foam around the edges of the Polysio boards to keep them firmly in place.

Insulating the Roof Ribs in a Van

Closed-cell spray foam added inside the cross ribs of a van's ceiling
Adding closed-cell foam inside the van’s cross ribs

In our Ford Transit van, there were also four ribs that ran across the roof of our van. These ribs are hollow, meaning there is substantial airspace inside the ribs that transfer heat into (and out of) our interior van space. We must eliminate this ‘thermal bridge’ to reduce the heat transfer from our van’s roof to the interior. And we achieved this by spraying closed-cell foam into the hollow ribs. When the spray foam expands and dries, it pushes out the air, and in its place is a robust insulation material with an R-7 insulation value.

To learn more about our camper van’s ceilings, read: How To Build A Cedar Plank Ceiling In A Camper Van

Insulating Our Van’s Windows

We absolutely wanted to install windows in our camper van because we wanted to be able to see outside and allow natural sunlight to enter during the day. So, we installed two small RV windows on each side of the rear part of our van. However, windows greatly reduce a camper’s insulation abilities.

In order to insulate our van’s RV windows, we simply cut out the appropriate size piece of Reflectix to fit over the windows. Unfortunately, Reflectix isn’t the most beautiful piece of material. And so, we purchased some fabric and glued the fabric to one side of our two Reflectix pieces.

Bonus: The Reflectix + fabric blocks the light from exiting our van at night, which increases privacy and ‘stealthiness.’

Non-Conventional Camper Van Insulation Materials

There are two other products that we have that really help to increase the insulation rating of our camper van. One of them is to help keep our van cool during hot days, and the other item helps keep our van warm during cold days. However, these two items are not technically insulation materials but we feel they are worth mentioning.

Rigid Solar Panels

Two rigid solar panels on a camper van roof
Two rigid solar panels on our van’s roof

On our van’s roof, we have two 180-watt solar panels. We love these large panels because they, on average, bring us all the energy we need each day. But as a side benefit, these rigid solar panels also cover roughly 40% of our van’s roof and provide valuable shade over the van’s sheet metal. Harvesting electricity AND protects a portion of our van from the sun. It’s a win-win.

Important: To truly benefit from shading your camper van roof with solar panels, it’s important for the solar panels to be rigid. Rigid solar panels allow for proper dissipation of heat under the panels. Flexible solar panels are becoming more popular, but these panels don’t provide the same level of insulation properties because heat from the sun is easily transferred from the panels to the van’s roof.

Yoga Mats and Area Rugs

Camper Van Bed and Living Space
Our Mexican Rug From Oaxaca Covering Our Van’s Floor

On the coldest days, no matter how well the floor is insulated, the van’s floor will always be cold. So much heat inside a camper van is lost because the freezing floor radiates the cold to the rest of the van. We’ve found that placing area rugs, and ESPECIALLY yoga mats, does a great job of separating the cold floor from the rest of the van’s interior space. This also works if you have a foam sleeping mat designed for camping.

Insulation Materials We Don’t Recommend

All the insulation materials we talked about and used above are all highly recommended. They’ve kept our van toasty during cold days and cool during the summer months. However there is a short list of insulation materials that we do not recommend when building a camper van. We discuss these materials below.

Fiberglass & Rock Wool Batts

Fiberglass batt wrapped in packaging
Fiberglass batt commonly sold at big box stores

Fiberglass and Rock Wool Batts are common building insulation materials for new homes. And though you could (and many van lifers do) use fiberglass and/or rock wool batts in their van insulation projects, we would recommend against it for two main reasons.

  1. Moisture Retainment: Fiberglass batts absorb moisture, and the material is known to provide a breeding ground for mold.
  2. Health issues: Both fiberglass and rock wool are unsafe to breathe in and can cause itchy irritation in the lungs and skin. High-quality masks and gloves are required if handling fiberglass and Rock Wool insulation materials.

If you do decide to use either fiberglass or rock wool insulation batts, it’s important to wear proper protective equipment (PPE) and to seal the insulation areas with a plastic layer to prevent the insulation material from separating and floating around inside the camper van.

Instead of fiberglass or rock wool batts, we recommend using Havelock’s Sheep’s Wool much more.

Denim Batts

Denim batts in plastic packaging
Denim insulation batts

Denim batts are also a common insulation material that is made from recycled blue jeans and are non-toxic. Sounds too good to be true? Unfortunately, we think they are.

Unfortunately, the denim material is prone to water absorption and, inevitably, mold growth. For this single reason alone, we would not recommend using denim batts as insulation for camper vans. Instead, we recommend, again, using Havelock’s Sheep’s Wool as a great substitute for denim batt insulation.

Thinsulate by 3M

The company 3M developed Thinsulate as a thermal insulation layer for clothing to compete against expensive down insulation. Recently, more and more van builds are using 3M’s Thinsulate material for insulation mostly because of the material’s ability to allow moisture to pass through. This means that condensation can easily pass through the Thinsulate material and evaporate, instead of being trapped inside the van. This is great when considering mold and mildew issues.

However, we don’t recommend using Thinsulate as camper van insulation because not only is this proprietary material considerably more expensive than alternative products, but Thinsulate’s R-value isn’t nearly as high. Pound for pound, insulating a van with either Polyiso foam boards or sheep’s wool is a much better option.

Do You Need a Vapor Barrier When Insulating a Camper Van?

When we were first planning our van build, we watched numerous YouTube videos of people insulating their vans and then putting up a vapor barrier over the insulation. Perplexed by this, we did more research.

What Is a Vapor Barrier?

A vapor barrier is a material that blocks moisture (and vapor) from passing through. The idea is that if you block moisture from getting behind the walls, then you won’t have to worry about moisture buildup and mold in your insulation. Since moisture is also the catalyst for rust, the idea of a moisture barrier is to prevent rust from forming in the van’s chassis and metal frame.

Usually, a vapor barrier is a thick plastic sheet that is placed over the insulation material and sealed by taping the edges of the plastic sheet to the van. Therefore no air and moisture can pass through.

Why We Do Not Recommend a Vapor Barrier

Just as it’s foolish for mankind to try and control nature, we think it’s foolish to try and prevent air and moisture from going where it wants to go. To completely seal off an area 100% is excruciatingly hard. air will always find a way to enter, and this is especially true in a camper van that is always shaking and vibrating.

The worst part is, if you insulate your van with cheaper materials that are prone to molding but install a vapor barrier, what happens if/when the vapor barrier fails? Moisture will permeate behind your walls and into your insulation, fostering mold growth. And because it’s behind your walls, you won’t even know it until it’s too late.

We think it’s much smarter to either insulate your campervan with materials that are impermeable to moisture (and thus don’t promote mold growth) or insulate the van with products like sheep’s wool that absorb moisture and release it safely back into the environment.

Compliment Your Campervan Insulation With a Heating Source

Having awesome van insulation will allow you to travel in much cooler weather than you would otherwise. But eventually, no matter how good a campervan’s insulation is, the van’s interior WILL get cold. Cold air will always find a way in eventually.

Therefore, we recommend installing a heating source inside your van to keep the interior warm and toasty if you plan to live and travel in your campervan during the winter.

We installed an Espar Diesel Heater in our van, and although the heater came with a hefty price tag, we could continue traveling comfortably in our van in temperatures well below freezing.

In fact, we think that having an internal heating source is so important to van life that we wrote a separate article just on this topic.

Learn More: How To Heat Your Campervan In The Winter

Sound Deadening Insulation

We haven’t talked about it yet, but before we installed any insulation in our campervan, we purchased Noico’s Sound Deadening Mat to dampen any sheet metal vibrations in our van.

Because sheet metal is so thin, the material easily vibrates and allows sound to pass through easily. By applying these hefty sound-deadening strips directly on the flimsy sheet metal all over our van (walls, ceiling, floor, and back doors), we increased the weight of the sheet metal and dampened the noise.

We’ve met people on the road who hadn’t thought of putting sound-deadening strips early on in their van build and regret it later on. We recommend picking up a sound-deadening mat and placing little strips all over your van before adding your insulation.

KILMAT | Sound Deadening Mat

This hefty, self-adhesive mat sticks directly onto thin sheet metal, dampening the vibration and rattle while driving. Cut the mat into strips and place it on your van's metal floor, ceiling, and walls.

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Top Tips When Insulating a Camper Van

Below are some of the top tips we learned when installing our own insulation in our campervan.

1. Wear a High-Quality Mask

Eric sitting inside a camper van after painting the interior walls

Seriously, we learned this the hard way. Whether you’re working with toxic materials like fiberglass and rock wool or not, it’s important to always protect your skin and your lungs by wearing proper protective equipment like a high-quality filtered mask.

Reusable Respirators

Suitable for painting, woodworking, and other projects that put you in contact with tiny particulate matter and noxious gases. Additional filters and ear plugs included.

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Spray foam off-gasses some pretty toxic chemicals into the air, and you don’t want to breathe in styrofoam particles when cutting the foam boards. Protect your lungs by wearing a high-quality filtered mask. This mask will also be useful when it comes time to paint the inside of your van.

2. Wear Latex Gloves When Using Spray Foam

Hand with dried spray foam stuck on skin
Spray foam bonded onto skin

Similarly, when working with foam spray, we stupidly used the spray with our bare hands and touched the newly extruded soft foam with our bare skin. Big mistake. Once the foam dried on our hands, it took DAYS to peel off fully.

Long story short, wear gloves when you work.

3. Insulate Hard To Reach Air Pockets To Reduce Thermal Bridges

When we separated the insulation of our van into the walls, floor, ceiling, and windows, we really oversimplified it. On top of these primary sections, there are also many small, hard-to-reach cavities all over the van that contain air that needs to be pushed out in order to insulate the van properly.

In many cases, the only material that can insulate these hard-to-reach cavities is spray foam. Because the spray foam is extruded from a thin straw, it’s easy to insert the head of the stray into the van’s tiny areas. We used countless cans of spray foam from Great Stuff to insulate lots of tiny pocket areas all over the van.

4. Consider Professional Spray Foam Services for Your Camper Van

Although not the greatest in terms of environmental impact, if you’re in a time crunch and your budget allows, getting your van’s interior professionally spray-foamed is fast and effective. Professional spray foam companies will enter your van, seal off any areas that you don’t want to spray (like the front cab, for example), and the heck out of everything else. And when it comes time to build the rest of your van conversion, simply shave away the unwanted areas of spray foam.

Getting professional foam spray services is an effective way to really seal the interior of the van to prevent unwanted heat from escaping or entering. Also, because of the blanket application of the spray foam, this method is probably the best way to create a true vapor barrier.

5. Don’t Forget About Insulating Your Camper Van’s Wheel Wells

The wheel wells are an important part of your van’s floor that should be insulated. This is because even though the wheel wells come up and into the van, on the other side of the wheel is cold air that will easily be radiated into the van if not properly insulated.

First, we added several strips of Kilmat Sound Deadening Strips across the wheel well. Then we insulated our wheel wells with a layer of Reflectix and then we built a plywood box around each of them.

6. Insulate Your Van’s Floor With an Area Rug (or Yoga Mat!)

Just like we mentioned before, consider placing a yoga mat, a foam camping mat, or an area rug on the floor of your van when temperatures get cold outside. No matter how well a floor is insulated, it will always get cold eventually and become uncomfortable to walk on with bare feet.

And a frigid floor is a huge source of lost heat in a van.

Therefore, when it gets cold outside, we bring out our yoga mat and area rug to place on top of our luxury vinyl plank floor. While this isn’t going to insulate the floor 100%, we’ve certainly felt the difference in the air temperature between having a bare and carpeted floor.

7. Consider Installing Rigid Solar Panels

We didn’t know it at the time of installation, but we realized later on that the two large solar panels on our roof do a very effective job of preventing heat from the sun’s rays from entering our campervan. Our rigid solar panels take up about 40% of our roof real estate, and the shade that the panels provide to our roof has been a boon to keeping the inside of our van cool on sunny days.

Camper Van Insulation FAQ

What Is the Best Insulation for a Camper Van?

If we had to pick one insulation as “the best insulation for campervans,” we would pick Havelock’s Sheep’s Wool. Environmentally friendly and sustainable, mold-resistant, moisture controlled, and easily installed almost everywhere in the van, sheep’s wool is our favorite insulation for camper vans.

Best of all, sheep’s wool isn’t all that expensive. For just a few hundred dollars, you can easily insulate your entire van. Cost-effective, efficient, and the material works great.

To learn more about sheep’s wool, visit Havelock’s website and check them out!

Is It Worth Insulating a Van?

We understand not everyone has the time nor the budget to install premium insulation materials in their vans. And for those who don’t plan to travel in extreme weather climates, the impulse to simply forgo campervan insulation altogether might be tempting.

But we implore anyone who is wondering whether insulating a van is worth the money, time, and effort to put in at least a basic amount of insulation. Even warm weather climates get cool in the evenings, and you never know where you’d like to travel with your campervan in the future.

Plus, even the most basic amount of insulation can prevent unwanted loud noises from entering your van. Think large diesel truck noises at 3 AM!

How Do You Insulate a Van for Hot Weather?

Insulating a van for hot weather is the same as insulating it for cold weather. By installing insulation materials with high R-Values, you can prevent scorching heat from entering the van, just as it prevents heat from leaving in cold weather climates.

However, to help keep your campervan cool, it’s also crucial to have proper ventilation to promote air circulation. This is done primarily with a vent fan on your van’s ceiling (like a Maxair Maxxfan) to remove hot air from inside the van and bring in cooler air from outside.

How Do I Stop Condensation in My Van?

Though we don’t have any hard evidence, preventing condensation from forming inside a van is nearly impossible. It’s just natural. When you’re parked overnight in frigid temperatures, condensation will form on your van’s metal walls when the air heats back up in the morning. There’s no stopping it.

To stop condensation in a van, some people have resorted to installing ‘vapor barriers’ to prevent air from passing behind their walls. But we don’t think a vapor barrier can effectively stop 100% of airflow.

To combat moisture and mold, we much prefer to install materials that either do not absorb moisture and water or absorb water but easily release the moisture later without inducing mold growth. For this reason, we like using sheep’s wool, Polyiso foam boards, Reflectix and spray foam for most of our camper van insulation.

Does Reflectix Keep Cold out of a Van?

Yes! Not only does Reflectix do a great job in reflecting radiant heat from the sun, but it is also effective in keeping out the cold.

We have two small RV windows in the back of our van, and at night, in cold weather environments, cold air pours into our van through the windows. But our DIY Reflectix window covers do a great job of keeping the cold air out from our van.

What Is the R-Value of Reflectix?

The R-value per inch of Reflectix is 7.0.

Does Foil Insulation Really Work?

Foil by itself provides a good radiant heat barrier, but we wouldn’t even think about using foil insulation as our primary camper van insulation solution. Luckily, several great insulation materials are sold with foil attached as a top layer, such as Polyiso foam boards and Reflectix. With these products, you get the benefits of a more robust thermal layer with a foil top layer to reflect additional heat.

Does Bubble Wrap Work As Insulation?

Yes, it does! Actually, Reflectix is just a glorified bubble wrap with a foil top layer. But just like Reflectix, bubble wrap is limited when used as a primary insulation material solution. Reflectix (and bubble wrap) works best in limited situations and in conjunction with other insulation materials in a camper van.

Final Thoughts: Insulating a Camper Van Works!

While insulating our van wasn’t the most interesting part of our van conversion build, we’re thankful that we took the time to insulate our camper van properly.

Between our sheep’s wool, foam boards, and Reflectix, the insulation we installed helps to keep our van BOTH warmer during cold days and cooler during sunny days. Maintaining the internal temperature of our camper van has helped make long-term van life more comfortable and easier. If we could build a second van conversion, we would insulate our van with exactly the same materials.

But if you are planning to travel in a van during the cold winter months, we recommend having a heating solution in your van. Simply having good insulation isn’t enough to combat freezing temperatures.

Go Back: DIY Camper Van Build Guide

If you have any questions about insulating a camper van conversion, please let us know in the comments section below.

Happy building!

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