In existing spaces oil based paints or vapor barrier latex paints offer an effective moisture barrier.
Vapor barrier for bathroom walls.
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.
Interior bathroom and kitchen walls for example are areas where there is.
The inner surface in colder climates and the outer surface in hot humid climates.
Normally interior walls do not require a vapor barrier but there are some situations where it is highly recommended.
It s usually a thin layer of plastic that sits between the drywall and the studs.
Between tub and shower sinks and toilet a bathroom has a high potential for water damage not only from leaks of liquid water but also from water vapor that can collect inside exterior walls and condense.
Vapor barriers are usually best installed on the side of the wall that experiences the hotter temperature and moister conditions.