Good quality insulation has a number of functions in a camper van conversion. In cold weather, it retains heat in the interior living space and, inversely, it keeps the interior cool when the sun is beaming down on the outside. It also prevents condensation forming on the inner surfaces and provides sound insulation and dampens vibration to allow for a more pleasant driving experience.
When I started this project, I researched a number of different options for insulating the van and found there are as many different opinions on this subject as there are brands of insulation on the market (that’s a lot!)
I eventually settled on a 4mm bubble foil insulation along with some sheeps wool quilting to fill the empty voids behind the plywood panels. The bubble foil was ideal as it was easy to apply to the bare metal surfaces using Trimfix spray adhesive. Its easy to work with and cut to the shape of the panels and it’s flexible enough to be moulded around the curved surfaces of the panels. The sheeps wool quilting added an extra layer of insulation and the added benefit of sound deadening and gave the van a really solid feel, especially in the inner voids in the back and side door panels.
One the bubble foil was all glued into place, I filled the voids with sheeps wool, then added another layer of foil over the sheeps wool. Aluminium tape was then used to seal all the joints and in the foil, resulting in an airtight envelope which also doubled up as a vapour barrier. A vapour barrier is essential for preventing moisture in the air inside the van from becoming trapped in the spaces behind the interior panels. Moisture that becomes trapped in these spaces will almost never fully dry out and will inevitably cause the bodywork to rust.
To make the job easier, the door rubbers and trims can be easily removed and refitted once the insulation is in place. The larger, flat panels such as the roof are quick and easy to do and the spray adhesive makes life very simple but some of the struts and more complex shapes can be tedious to do. It’s important to remember that the Carpet lining will be glued directly to the surface of the foil in some areas so try to make it as flat and neat as possible and avoid overlaps which can sometimes show through the Veltrim finish (I found this out the hard way).
I used the same bubble foil insulation on the floor of the van although it wasn’t necessary to glue it down since the plywood floor would be laid directly over it and screwed into place. I just cut the insulation to the shape and joined all the pieces with foil tape.
Once all the insulation was in position and the joints sealed, I was ready to ply-line the camper van interior.