A vlog in which I cover myself liberally in cobwebby spray adhesive as I try to stick foil-wrapped bubblewrap onto the walls of my Toyota Proace van in order to form a moisture barrier. I also cut up some wooden battens for the floor and begin to map out where to put them.
A vapour barrier is a much discussed topic in van building. The gist is to stick a moisture-impermable fabric on the walls, floor, ceiling – everywhere – so as to prevent any moisture inside the van from being able to reach the walls where it would condense into water if it’s cold outside. You don’t want this because moisture will rot the metal of the van and it will rot the insulation stuck to the walls.
However, two schools of thought exist. One says don’t have a moisture barrier because if anything condenses you want it to be able to evaporate so you need a good flow of fresh air around it. This school also sometimes suggests that a moisture barrier will trap damp between it and the walls, actively provoking rust.
The other school says do use a vapour barrier precisely because this will stop any moisture in the van – which mostly comes from you breathing out overnight when it’s cold, as well as cooking vapours of course – from ever reaching the insulation or the walls so it won’t be able to condense. Also, the only trapped moisture will be anything that was in the air at the exact moment when you sealed it up and that’s not going to do much harm.
I went with the second school and used the foil-wrapped bubblewrap so beloved of van builders for insulation (which it really isn’t, see my prior posts) because the one thing it is actually good at is being a moisture barrier.
Gaps between the metal and the sheets are covered with silver metallic sticky tape; you really trying to make an entirely sealed cavity round the inside of the van.
With the barrier in place, I could re-attach the original ply lining although I’d forgotten to mark where the original screw holes were so I bought some self-drilling (not self tapping) screws and forced them through with my electric drill. I also had to chop about 5mm off all the edges of the ply because it had less space once the vapour barrier was in place.
Another bit of the conversion I started was chopping up wood battens on which the new floor would lie. As I have very minimal headroom in the van, I needed very slim battens so I used 19mm x 38mm, with the 19mm being the height. I just can’t afford to lose any more headroom else I’ll barely be able to sit up.
Finally, I chopped a bit off the two wheelarch covers (plywood, part of the original lining kit) but mucked it up and will probably re-make them later.