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How do you Insulate a Van Conversion? (7 Best Materials + Our Experience)

How do you Insulate a Van Conversion? (7 Best Materials + Our Experience)

Insulation is a crucial stage of any van conversion. It might be tempting to cut corners at this point, but it’s really important that you contribute as much time and money as you can afford to this critical part of the process.

You can use a range of materials, including multi-foil, sheep’s wool, foam board, reflectix, thinsulate and spray foam. There is no one right answer to insulating your van, but doing a good job now will save a world of problems and discomfort in the future.

Here’s the 7 best materials to insulate a van conversion:

1. Multifoil

Multi-foil insulation is lightweight, effective and often combines a water-resistant layer. Its efficiency depends on its price and thickness, but it is generally very easy to work with and provides good coverage without too many joins to compromise the insulation.

More info:

2. Sheep’s Wool

Sheep’s wool insulation is expensive but is well worth considering in a small space because of its many positive assets and low environmental impact. This natural insulation provides high quality sound and heat protection. It is completely natural, recyclable and doesn’t pose any chemical health hazards to people or the environment.

Sheep’s wool insulation gives value to something that has largely become a wasted by-product in the farming industry. It comes without glues or additives and can be compressed for delivery, making it cheaper to transport. It works well in summer as well as winter and is naturally flame resistant. It can also absorb condensation reasonably well without getting ruined!

More info:

3. Polyiso Foam Board

Polyiso foam board is a kind of rigid, foam insulation which is extremely easy to get a hold of and particularly cost effective. It is much more effective than loose-fill alternatives and can be coated in plastic or aluminium to improve its efficiency or make it waterproof. The rigidity can make it awkward to work with and you should cut it using a utility knife rather than a saw.

If water does accumulate inside the boards, it will stop working, so it’s important to tape and seal the gaps between boards to prevent moisture and air flow entering the gaps. It is extremely difficult to prevent any condensation or moisture entering the walls of the van, so only use foam board if you are convinced you can install an excellent vapor barrier (not an easy feat).

More info: Matcha Moto

4. Reflectix

Unlike the other insulation that I have mentioned, Reflectix directly reflects heat rather than storing heat and slowing its transfer. Its texture is similar to bubble wrap and it’s specifically designed to be efficient in small spaces. However, if you don’t provide a space for air between the wall and Reflectix, it has practically no insulating value whatsoever.

You’ll want to use it in addition to other forms of insulation.

You will see many you tube videos and bloggers sticking Reflectix straight to the wall, but they are wasting their time and money. It can be easily cut without the need for special masks or protective clothing.

More info: Outdoors Embrace

5. Thinsulate

Thinsulate is commonly used in gloves and fleeces, but it can also be used to insulate your van conversion. It is particularly effective as a sound barrier and it comes in a really wide roll which makes it simple to work with, without too many gaps or seams in the insulation.

Thinsulate is really light and easy to cut, and it can also be stuffed into any cavities. You should wear a protective mask for the glue that you need to use to install it.

More info:

6. Spray foam

Spray foam has got one of the best R values and it’s amazing at repelling water and staying free of damp and mold. It is particularly difficult to install yourself, as it is a messy substance that is difficult to clean up. It’s also not difficult to make the walls flat and even if you aren’t used to working with the substance.

It’s an expensive option, even if you do it yourself, and it can’t be removed once it’s been installed. However, it is extremely efficient so if you have the money and expertise (or access to a trusted professional), then it’s a brilliant option for insulating your van conversion.

More info:

7. Re-purposed insulation

If you are working on a tight budget, you’ll have to get creative any way you can. This includes how you decide to insulate your van conversion. You can put a message out to your friends and family to see if anyone has some left over insulation from a recent home remodeling project.

If you come up empty with your immediate friends and family – try a post to the general public on a local Facebook group or similar website looking to connect people with free stuff – like

A Note on “R” Values

When someone refers to “R” value, they are talking about the resistance that a certain substance has to the flow of heat. For insulation, the higher the R value, the more effective it is at keeping you warm. The R value refers to resistance per inch of thickness, so the more insulation you install, the higher the overall value.

The thinnest insulation with the highest R value on the market is probably Aerogel, a revolutionary, extremely fragile material with an R value of 10. It is only 10 mm thick but far too expensive to be used in most construction projects. As humble vanlifers, we will have to turn to cheaper alternatives.

Our experience – insulating a van on a budget

My partner and I live a low impact lifestyle that recycles and re-purposes materials whenever possible. So, when converting our Peugeot Boxer from a transit van into our home, we used a patchwork quilt of left-over scraps of insulation, then covered that in a layer of multifoil which we purchased.

We got the insulation from friends and family that had it laying around after construction projects, but you could easily reach out on social media to do the same. Before anything else, we gave the van a really good clean and painted the interior metal with anti-rust paint to protect it in the future. Then we stuffed our re-purposed insulation into all the nooks and crannies we could find.

Here you can see our scavenged insulation and starting to cover with multifoil.

Next, we screwed small pieces of wood on the wall, floor and ceiling. We used these as a frame where we could attach the multifoil insulation with a staple gun.

Having covered the van with multifoil and making sure there were no joins left uncovered, we measured and cut plywood boards which we screwed to the same wooden frame we had stapled the insulation to. We had already brushed and treated these to give the van a cosier feel and protect the boards from moisture.

We covered the joins between the boards with sealant and made a border of scrap wood to neaten the edges around the windows. Other final touches included laying a lino floor to make the van easier to clean and protect us from splinters and cutting up an old aluminium camping mat to place over windows in extreme weather conditions.

It took us about a month to complete this stage of the project, but it was absolutely worth it. Now we can comfortably camp in the mountains all year round, and save a huge amount of money on heating bills.

Our van insulation project from start to finish!

DIY vs hiring a professional to insulate your van:

Hiring a professional is obviously going to cost you more money. If you are insulating your van with a substance like multi-layer foil or thinsulate then I would recommend you go ahead and do it yourself. The process might seem a bit daunting, but there are plenty of youtube tutorials and how to blogs out there, making learning new skills easier than ever.

What’s more, the skills will stay with you for life and you never know when you might be thankful for your resourcefulness and competence in the future. If you choose to insulate with one of the messier or substances like yellow foam, then you can consider hiring a professional to do it for you.

It can cost over $800 to get your van professionally sprayed, whereas we spend $350 altogether for anti-rust paint, insulation, plywood panels, wood varnish and sealant and flooring. Then again, if you don’t have access to space to work or some of the tools that will need, it might make more sense to pay a professional.

You will know how much it will cost upfront and they have all the experience and equipment needed to get it done quickly and to a decent standard.


Do I need to insulate my van floor?

Yes, we recommend insulating your van floor. It’s unlikely that you’ll have the time or inclination to rip the floor up in the future so you should get this right the first-time round. However, the more you insulate the van, the more living space that you will lose, and the floor is less important than the walls and ceiling. If you have to choose between an insulated floor or standing room, choose the latter.

How you insulate your van floor will depend on the money and resources you have available. We recommend three layers when installing the van floor. The first will be your chosen insulation, the second will be a protective plywood layer and the third should be an easy-clean lino to keep the van clean and your feet free of splinters.

Does van insulation work for summer heat as well?

Insulation will help to keep you safe and comfortable in the summer as well as the winter. That being said, it’s easier to keep the heat inside than stop it coming in. Although insulation will slow down the heat of summer, you won’t be able to realistically stop the van from getting too hot with insulation alone.

It’s important that you seek a shady spot and open multiple windows to allow air to flow through the space. Placing a cool wet flannel on your forehead provides a lot of relief as the water evaporates from your skin.

On a really hot day it’s worth considering covering the windows with reflective aluminium and using a cooling system. We use the Propex hs2000 air heater which runs off butane or propane and also has a setting for cold air. As tempting as electric fans might be, they use too much electricity unless you’re connected to the mains.

How do you insulate a van roof or ceiling?

To insulate the walls and ceiling, fill any cavities with loose insulation. Then cover the walls in your chosen sheet insulation with glue or by stapling it onto a thin wooden frame. You create this frame by simply taking small pieces of wood and screwing them directly onto the van wall wherever possible.

Having stapled those down, you can cut plywood boards to size, or replace wall panels that already came with the van. You might need a second pair of hands to help hold the boards in place whilst you drill them in, or you might want to use a wall support to hold the boards up to the ceiling.

How do I stop condensation in my van?

Condensation is a big problem for van lifers, particularly in winter. The key to managing this annoying moisture is to crack two different windows open to create an airflow where steam and breath can escape. We installed a ventilation shaft in the floor and a sky light which is designed with two layers to always allow a little air to escape.

Even with those measures we get filled up with condensation on cold nights which can lead to problems like mould, a bad smell, and water gathering in nooks and crannies.

Some types of insulation, like multifoil, will integrate a vapor barrier into the insulation which acts as a barrier to moisture and prevents damp and mold getting inside the walls. Other insulation, like foam board, are particularly vulnerable to moisture and can be ruined for good by too much condensation.

We use old towel to wipe any damp surfaces in the morning and we also positioned the sky light window directly above the cooking system. If I’m cooking something that creates a lot of steam, then I crack it open to release some of the wet air. It’s important to open all the doors for a few hours per day when the weather permits. This allows air to circulate and dries out any accumulated moisture. Make sure food is properly sealed in plastic or glass containers where it can’t go bad because of damp.

Your choice of heating system can help reduce condensation as wood stoves suck moisture from the air and air heaters have a vent where they release excess moisture. It is not a good idea to buy a dehumidifier unless you have access to mains electricity.

Final thoughts…

There is no one right answer to insulating your van, though it is a very important process to go through. Don’t fall into the trap of copying youtubers sticking reflectix straight to the walls, and don’t be afraid to pick up some tools and give it a go yourself.


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