If you watch 5 different You Tube videos on how to insulate a panel van, you will probably see 5 different ways of doing it, and plenty of opinion on why any other way of doing it is flawed. We decided to do what made sense to us, and have settled on a combination of 3 different materials.
We started with with the side walls, wheel arches and doors, using a self adhesive foil backed foam material to provide both insulation and sound deadening. After a bit of shopping around we bought a10m roll from Ebay, the exact stuff we bought is no longer available, but the link takes you so something very similar. This was applied to large flat areas of the outside wall of the van, and was quite tricky to install on some places in the lower half of the van as we had to reach through the inner support structure and peel off the backing in a very small space.
Once we had covered as many of the flat areas as possible with foil backed foam, and cut it to fit over the wheel arches, we covered the flat areas of the ceiling as well, leaving a gap where the 2 skylights will be fitted.
The next step was to add foam insulation. We chose recycled PET bottle insulation, as it is not moisture absorbent and we liked the idea of using a recycled material. We filled the voids in the lower half of the sidewalls between the support frame and the outer wall, and poked (technical term)smaller pieces in the voids in the main structural pillars. The plastic ‘wool’ is very easy to tear and this stage was much faster than the self adhesive stuff. The upper sections of the van didn’t have a handy frame to retain the wool, so we used double sided tape to hold it in place until the ply lining could be replaced.
The question of whether to include a vapour barrier or not seems to be the most divisive amongst those who publish advice on van conversion online. We have decided to include one, as it makes sense to us that sleeping in a van will produce a lot of moisture in the air and, even with good ventilation, preventing that moisture from condensing on the metal work and pooling in corners seems like a logical thing to do to minimise the risk of corrosion.
To create this vapour barrier, we used quilted foil insulation from a local DIY shop which comes on a roll, and used foil tape to seal the joins between sections.
We have only done the sides so far, and will do the ceiling just before we fit the lighting and cladding, and seal the roof section to the sides with foil tape. The next job is the fit the roof lights and then on to the electrics.