Vapor Barrier

[Sasha]

I am remodeling my upstairs bath. I removed all walls to put Durock. I don't want however remove ceiling as it is more or less in good shape. The ceiling does not have any vapor barrier right now. I heard once that some sort of oil based or another primer makes acceptable vapor barrier. Is it true? I checked attic insulation and didn't find any condensation there.

[gary]

If the house is older and has a few coats of oil paint you are ok. If you pull down the drywall there to put up a vapor barrier then you might as well continue on to do the rest of the house too, also the exterior walls.

Gary