Ok here it is, for those of you who like to do winter camping & not have Niagara falls CONDENSATION drip on your head
This set up works quite well with almost zero condensation.
the top diamond plate is of course the trailer roof.
the left side is a wood stud that runs under the metal stud "not shown"
I'm using R-19 Denim insulation - it really only expands to 3.5"
below i'm using 3/4" blue board mainly to compress the Denim - so there is no air space between metal roof.
the lowest layer is 1/4" paneling