Where to place vapor barrier?

[flying kurbmaster]

here is what it looks like under the van

 

[akrvbob]

More than 4"!? I thought I was already overkilling it...

Oops! Since you don't mention that in this thread, I didn't put the two together. One problem with not using a name is you lose your identity, I can't keep track of all these oddball names.  Eventually I associate them with a person, but my old brain takes awhile.
Bob