Insulating a van: Is it interior or exterior moisture that's the problem?


New member
So are we worried about mold developing from condensation from interior sources of moisture (breathing, perspiring, cooking), or are we concerned about mold developing on the inside of the metal exterior? If we were to have a foil barrier with the foil facing inwards, would we not be creating conditions where moisture would be kept inside, as though we were baked potatoes in a foil jacket?

If we have a foil barrier glued to the van walls followed by foam or fiberglass insulation and then the interior wall panels, does the foil barrier do anything?

I'm not even sure if we are insulating to keep in warmth during cold weather, or to keep out the heat in the summer... Can anyone enlighten me?

For what it's worth, we live in the maritime Pacific NW and would do most of our camping in western Canada and the western US.


Expedition Leader
I haven't noticed any mold, but I've delt with minor rust issues from the moisture. Luckily my heater (espar d4) blows out superdry heat to combat the moisture... somewhat.
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Both types of moisture can be an issue.
Take a look at the below link, as well as his flooring and other vids on insulation. There's a lot of good info.
It also depends on where you are going to be, multiple climates, humid, dry, ect.
I think Gorge's methods may combat them all.
There are some who just ventilate a lot. Keep a lot of fresh air moving through.


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