Help Tia! I'm new here, prepping walls/ceiling for insulation. Rust paint?

[Robin97396]

I'd hate to think about how much water the foam could hold. Foam holds water, and water makes mold. That's why we specifically use closed cell foam to insulate, iether in rigid foam or spray foam.
At first I thought you were talking about putting it on the interior surface, like so you don't bump your head.

[spenceronehalf]

If I used the foam from the seats I'd be adding ... A LOT OF MICE TO THE BUS

[Robin97396]

If I was stuck in Alaska in an uninsulated bus during the winter, you can bet I'd MacGyver that foam right up on the ceiling. Mice and all.