A vapor barrier is also helpful to keeping a basement insulated and warm.
Vapor barrier inside basement walls.
Water vapor can pass through building materials in several ways including direct transmission and by heat transfer but studies suggest that fully 98 percent of the moisture transfer through walls occurs through air gaps including cracks around electrical fixtures and outlets and gaps along baseboards.
A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.
A vapor barrier s job is to keep water vapor in humid air from diffusing through one side of a wall and finding a cool surface inside the wall.
After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.
Whether or not you need a vapor retarder hinges on three main factors.
The material is stapled to the frame of a basement wall before it is finished with plaster or drywall.
The science of moisture movement.
Plastic specifically 6 mil polyethylene plastic is.
Polyurethane sheeting is a typical vapor barrier that contractors use to prevent moisture from penetrating the walls of a basement.
Without a vapor barrier in place condensation inside the walls could ruin the insulation and promote the growth of harmful mold and bacteria.
Not every wall does.
The construction of the wall for instance is vital to the use of a vapor barrier.
Thus installing vapor barriers on wall surfaces must.
In winter the dew point of the interior air is typically about 50 f assuming an air temperature of 70 f and a relative humidity of 50.
Not to be confused with a vapor barrier which is placed on the warm side of the wall just in front of the insulation and behind the drywall a moisture barrier goes against the basement wall.
A vapor barrier reduces the movement of water vapor by.
The main concerns are condensation and drying potential.
1 on the interior wall between the heated and unheated portion of the basement i would not use with a vapor barrier.