Interior stripped out, and I have painted as many interior metal panels that I can access. I noticed a lot of condensation on the inner roof, now that the headliner is out. I also stripped out the black, what looks like house roofing tar paper. The condensation worries me, but I suspect that it is from the wild temperature swings we have had recently. I wondered about using a spray foam insulation, to cover the inner roof, and perhaps some of the other areas I could apply it, such as the inner 1/4 panels, etc. I figure it would help prevent the condensation, and perhaps make the vehicle sound quieter from road noise, etc.

Any opinions on this course of action, pros/cons. Any suggestion as to the type of spray foam insulation that might be good for this?

Other suggestions for insulation materials suitable for the inner roof, etc? It has to be thin enough to allow me to get the headliner back in place, (hardboard style, not hoops).

Thanks.