Van Life

Campervan insulation: what to use and why

Researching how best to insulate a campervan was one of the first confusing things we encountered. Everyone seemed to have their own way of doing things and the choice of materials out there was vast – and I’m about to add to your choice of options! After a lot of reading and researching, here’s how we ended up insulating our van and why.

After a good clear out and clean, we started work by first applying some sound deadening sheets to the van. This step is optional and I was initially hesitant whether to do it or not, especially as the material is not the cheapest, but I’m really glad we did as it has made some good difference in muffling the sound of the vehicle’s vibrations and noise when driving. We went with the popular Dodo dead mat which was very easy to work with – you just cut the roll to size, peel back the contact sheet, and press the adhesive side onto the surface of the van. You can hear the difference the mats make immediately by giving the van a knock with your hands before and after application – it doesn’t completely ‘deaden’ the sound but it’s definitely a lot quieter and less ‘tinny’.

We applied a small strip to each panel around the van’s wall and ceiling which was plenty to do its job. This was actually a little more than the directions suggested to use but I’ve seen other van builders cover every inch of metal inside which I personally don’t think is necessary; the only thing we covered in its entirety was the wheel arches. In our van (VW T5 LWB), we used just over half of the Dodo mat roll. You don’t need anything else special to fit the sheets, though you should buy yourself a wallpaper roller or similar as the mats are dense and come in a hex pattern on top, and are rather painful on the knuckles to press down after a while!

When it came to the actual insulation, figuring out what we should lay on the floor was more straightforward than the walls. Like most van builders, we used insulation boards (Kingspan available from Wickes) laid in between timber beams. Because of the low head height of our van, we opted for the thinnest boards we could find (25mm) so as not to lose any more space. You can read more about our van flooring in this post here.

Van conversion part 1: how to lay a new floor

For the walls and ceiling, we were torn whether to use insulation boards here too, but to try and save on space again, we opted for something more compact and used insulation rolls instead. We went through four rolls of Diall insulation which is made from recycled plastic bottles and was really simple to use – it’s soft, non-itchy, and safe to handle and breathe in unlike some alternative materials you can buy. After leaving the material unrolled in the van overnight to expand to size, we began cutting, tearing, and stuffing it into every surface and crevice of the van’s walls and ceiling.

On large flat surfaces like the sides, we used a general-purpose adhesive spray to keep the material in place, and while this wasn’t difficult to apply it was a bit messy, especially when using on the ceiling, so spray carefully and make sure you wear goggles!

When finished, we were left with a giant marshmallow van.

Next, we used Diall reflective bubble insulation to cover the stuffing. When I said earlier that everyone has their own way of doing things, this is one step that some people skip and argue you don’t need.

There’s a bunch of theories behind how best to insulate your van, and the reason behind using this bubble-wrap-tin-foil is to create a ‘vapour barrier’ between the insulation and the interior of the van. The idea is to stop the condensation you give off naturally – and from any cooking you do inside – from reaching the insulation and essentially, the body of the van, and to avoid water from collecting in the insulation where it may not evaporate easily, and help prevent the possibility of any rust from forming due to this water resting on metal surfaces over long periods of time. This is why we’re also fitting a fan to the roof of the van to help with ventilation – you’ll have to see my separate guide for this dreaded job…

I did a lot of research when it came to insulation, and one of the most helpful guides I found was from Tim over at the Restoration Couple on YouTube. I watched a lot of their videos documenting their own campervan conversion which I can recommend for a bit more inspiration and DIY-help.

Back to our build…

Before we completely covered everything with foil, we first attached timber beams onto the ceiling which we’ll later be using as the supports for our cladding. One mistake we made was not doing the same for the battens on the walls, as this was a lot more difficult to do after foiling when we could no longer see where you can screw into… oops.

Covering the insulation rolls with foil was simple. We cut everything to size and taped it to the body of the van using silver insulation foil until we created a complete vapour barrier, and from a marshmallow van, we became a space ship van!


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A post shared by Victoria + Dave (@thewagenhaus) on

Overall, insulating the van was not a difficult job, though much more time consuming than expected (like most of the jobs in this big project). But with this important step now complete, the more fun jobs could begin!

Coming up next in my van conversion diary:

  • Choosing and installing a ventilation fan
  • Cladding the ceiling and walls
  • Building our van bench/bed

Head here for all of my van conversion guides.

For the latest updates on our van conversion diary follow us on Instagram @theWagenhaus, or find me on Twitter @VicAdvisor, and sign up to Vic Advisor mailing list to be notified of new blog posts via email.

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