Vapor Barrier Roof Hot Humid Climate

In hot climates any moisture that condenses on the exterior side of the vapor barrier will be.

Vapor barrier roof hot humid climate.

In cold climates the location of the retarder is to the interior side of the thermal insulation. Even vinyl wall paper which has a low perm rating can induce moisture problems in warm humid climates where hot moist conditions tend to drive moisture into the wall from the outside of the building. Asphalt shingles store water from dew condensation due to night sky cooling and rain. In very warm humid climates if a vapor retarder is used naima recommends installing it to the exterior side of the wall.

The inner surface in colder climates and the outer surface in hot humid climates. In existing spaces oil based paints or vapor barrier latex paints offer an effective moisture barrier. In hot humid climates the design location and installation of the air and weather barriers are more critical than for the vapor retarder. In cold climates condensation is limited on the interior side of the vapor barrier as a result of installing all of the thermal insulation on the exterior side of the vapor barrier which is also the drainage plane and air barrier in this assembly.

When constructing unvented roofs with asphalt shingles in hot humid climates a vapor barrier must be installed between the asphalt shingles and the roof deck. Vapor barriers are usually best installed on the side of the wall that experiences the hotter temperature and moister conditions.