It s usually a thin layer of plastic that sits between the drywall and the studs.
Vapor barrier for bathroom walls.
Normally interior walls do not require a vapor barrier but there are some situations where it is highly recommended.
Vapor retarders are there to slow the diffusion of moisture so the building inspector is off base argues senior editor martin holladay.
In existing spaces oil based paints or vapor barrier latex paints offer an effective moisture barrier.
The inner surface in colder climates and the outer surface in hot humid climates.
Interior bathroom and kitchen walls for example are areas where there is.
If the tub shares this exterior wall i would put vapor barrier behind it if you can as the plastic tub surround will not give you a vapor barrier i don t think.
A vapor or moisture barrier is a layer of protection that is designed to act as a waterproof shield helping to keep condensation away from wood insulation and other mold prone materials that are located behind the drywall.
There is no need to vapor barrier the non exterior walls.