There is a proven alternative. Polyisocyanurate sheets for about $20/ at Home Despot or Lows, or gugle for insulation in a nearby city.. 1” for the walls and ceiling. Glue it in with Great Stuff cracks and gaps from an inexpensive progun. Cut a bit undersize, foam vertical lines of GS on the back, hold in place for a couple hours as you do the next one. Repeat. I think you can insulate for about $150. Get a few feet of Thinsulate too if you want to fill the ribs but it is not strictly necessary. Don’t be too fussy as the foam fills the gaps and it goes fast. Use the $350 you save for Camping!
I may be stuck with Thinsulate. Here's my dilemma, my PM has the upper and lower factory paneling and I want to use it so I had planned to to use Thinsulate behind it. I have a Van Bed Rug for the floor. What I'm trying to avoid is permanently gluing in a bunch of stuff all over the van walls and elsewhere.
My goal is to make things as modular and non permanent as I can. Not sure where the whole van thing is going to lead us. If we love it, we may end up switching the 136 out for a 159, who knows. This is all new territory for my wife and I. The van is a daily drive for me and mostly a weekend warrior for camping. No winter camping in Alaska or summers in Death Valley. Pretty much going to be a Tennessee van with maybe a few trips to FL or neighboring states.
I have those panels and that van. If I trade vans I’d leave the wall and ceiling insulation, take the floor. Mine’s modular too. I don’t see your logic??? BTW you are not going to leave a clean van if you glue Thinsulate in, and you should. 3M 90 holds.
Look at my thread, we seem to have had similar goals, van, walls, etc.
Saw some videos where they didn't glue the Thinsulate in at all, even used some gorilla tape in some areas. Still holding after 4 years. I figured I'd glue the Thinsulate to the back of the panels themselves and just pop them back in.
Maybe 1" polyiso held in place with alum tape or that red tape that's made for it. Read about a number of people who did it that way and it's still holding fine. Not sure what Im going to use on the ceiling for the final paneling. If one is using thin for the celling I would assume you could just have it laying on top of whatever type if paneling you use.