Campervan Insulation with closed cell matting

The ambulance came panelled and insulated.  Sadly, the old insulation we had in Campy Van- rockwool haphazardly shoved in behind panels- was inadequate and prone to condensation. It needed attention if we were to enjoy using the van in more extreme temperatures.  Therefore the insulation has actually been the main reason (besides the excess weight) for stripping back Campy Van to the bare bones.

I weighed up the different options and then decided to go with the material professional van converters tend to use: a closed cell matting, like yoga mats. It’s manufactured in Europe, by Trocellen.  Unfortunately, it doesn’t come as a self-adhesive option, though that can be ordered apparently in larger quantities.

For insulating the van I’ve taken a three pronged approach:

– expanding foam injected into hard to reach areas

-15mm foam boards glued to the body of the van

– finally, 5mm silver foil backed Polifoam covering all surfaces, bonded to the first layer and sealed around the edges with tape.

Expanding foam

A big issue with insulating a campervan can be cold bridging- where the insulation is inadequate and cold spots appear, which then causes condensation in those points.

Campy van has ribs, which, if I’d have insulated the over with the 15mm foam, I’d have eaten into our living space.  I decided to tackle the ribs with expanding foam.

Campy Vanclosed cell insulation with Polyfoam Mumonthebrink 9

Expanding foam was injected in the small crevices, behind metal supporting studs and in stud cavities.  The van has gobbled up 10 cans of expanding foam. I used a the expanding foam with a special applicator gun. This is a must: the application is much easier to control, it’s easier to be more precise.  Again this is something I learnt the hard way, by buying the cheaper spray version and struggling to control the quantities coming out.

After injecting the hard-to-reach areas with expanding foam, I had to wait 12 hours for the foam to go off and harden.  Then came the tedious task of carving off the excess which flowed into the wrong place. This took another couple of hours.

Expanding foam had to be applied in a couple of stages:

  1. large cavities needed to be filled in a couple of goes, as a single application would be mean that the core would not set, but remain a guey mess doing nothing for insulation.
  2. some cavities needed to be filled before the first layer of closed cell insulation went up, as afterwards I wouldn’t be able to access them to apply the expanding foam.
  3. I’m not always precise with measuring and had left little gaps in places between the closed cell insulation and the metal ribbing.  I applied tiny squirts of expanding foam into these crevices too.

I probably spent a day and a half applying the foam and then carving it back.

Base insulation

The 15mm polyfoam is stuck onto all the flat and accessible panels of the van. I’ve used a strong adhesive to hold it in place.

It’s a fiddly job measuring, cutting, glueing panel, glueing the insulation and then adjusting it into position.

Campy Van closed cell insulation with Polyfoam 2 Mumonthebrink 1

Initially, I was cutting the matting straight off the roll, then I realise I was struggling to make straight cuts vertically. Then, I started using a large table for measuring the insulation out, cutting and applying glue to it. I’d measure it up, then cut along the a long ruler joining my 2-3 measurements along the length of the cut.  I used a sharp stanley knife.

As I’ve gained expereince, I was then cutting lots of panels at once, then moving onto the gluing phase. It made more sense than running back and forth between measuring, cutting, gluing.  The glue was going off or not being ready to stick yet.  The batch method worked much better.

Campy Vanclosed cell insulation with Polyfoam Mumonthebrink 4

The process of insulating the panels with this layer took about 3 full (wo)mandays in total.  This was stretched over a 2 week period, while I also tended to other tasks.


The closing layer: Reflective closed cell insulation

The 5mm silver backed foam insulation was the final layer to apply.  To be truthful this was a task I had dreaded: I had electric cables and other elements – screws, posts, etc to consider.

The silver foil face was used facing into the van.

I put it up with the combination of glue to all the metal elements and welding – with a heat gun- to the 15mm insulation already glued to the walls. In places it looks super, following the contours of the van’s wall beautifully, in some places it’s sagged where I didn’t heat it well enough or didn’t press in in the right place to weld the two layers together.

Campy Vanclosed cell insulation with Polyfoam Mumonthebrink 7

All in all the task was more difficult than I’d anticipated, yet went quicker.  It took about a day and a half.

I’ve taped all seems.

Insulating the floor

The base van floor is ribbed for added strength and it is amazing how much the thin metal sheet on it can withstand!

The ribs, that provide the strength of the van’s flooring, are also the bane of one’s life when insulating the floor.  To overcome some of the height difference in the ribs, I cut and glued strips of the 5mm closed cell insulation to the floor.

Campy Vanclosed cell insulation with Polyfoam Mumonthebrink 8

I then used the same 15 mm closed cell insulation on the flooring.

Campy Vanclosed cell insulation with Polyfoam Mumonthebrink 1 Campy Vanclosed cell insulation with Polyfoam Mumonthebrink 5

I laid this in panels across the floor and slightly up the wall, welding it to the 15mm insulation on the wall, then I overlapped the 5mm insulation down over this floor insulation down to the wooden floor.

Campy Van closed cell insulation with Polyfoam Mumonthebrink 1

It seems counterintuitive to use a flexi material as insulation and I know that where the ribs are my floor won’t have the same insulation value as where the valleys are, since the insulation will compress, loosing the air and a lot of it’s insulation value.  I hope, however, that the level of insulation will still be adequate.

I’m using a 9mm compressed plywood panel, which is usually used in lorries for flooring. This will have a slight insulating value too and will possibly add a vinyl flooring.

If next winter proves my floor to be too cold, I’ll add some carpets, which can easily be removed to for cleaning.



And this this is what happens when you finish insulating the van:

Campy Vanclosed cell insulation with Polyfoam Mumonthebrink 6

You collapse into a big heap on the warm floor and admire your work. 😀

Leave a Reply

  1. Debbie Scott on

    can you help?
    I’m an avid reader of your campy van blog and am doing a similar thing. Can you tell me what make of 5mm polyfoam insulation you used on your van as I am really struggling to decide which one to use?
    Thanks in anticipation.
    Debbie Scott

  2. Monika,
    a most inspiring and helpful series of posts on your Camp Van, I am still struggling to secure a suitable and agreeable name for mine………. However, I reiterate the query from Debbie as to where one can procure the Trocellen Clesed Cell foam as I am unable to track down a UK seller (Not sure where in Europe you are but I am guessing the UK?

    Many thanks


    • Mumonthebrink on

      HI Debbie and Angus.

      Although UK-based I did some of the conversion in Hungary, where Polyfoam ( are based. The material was available in their retail shop.

      I’ll be honest with the hindsight of almost a year now- the insulation preforms OK, but I the work involved to stick it on I would either source a self-adhesive version or I would actually pay to get it done with spray foam insulation.

      If you are doing a self-conversion, I would highly recommend joining the SBMCC, if you haven’t already done so. I’ve had so much excellent advice and input from the folks on there.