Vapor Barrier Inside Basement Walls

A vapor barrier reduces the movement of water vapor by.

Vapor barrier inside basement walls. 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. If you have a framed wall that is adjacent to a concrete foundation wall where the vapor barrier is next to the drywall in front of the studs the fiberglass insulation gets wet and becomes a breeding ground for mold. 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.

The material is stapled to the frame of a basement wall before it is finished with plaster or drywall. 1 on the interior wall between the heated and unheated portion of the basement i would not use with a vapor barrier. 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. The construction of the wall for instance is vital to the use of a vapor barrier.

When the mold grows it will spread to. The science of moisture movement. 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. Not every wall does.

Without a vapor barrier in place condensation inside the walls could ruin the insulation and promote the growth of harmful mold and bacteria. Thus installing vapor barriers on wall surfaces must. Whether or not you need a vapor retarder hinges on three main factors. Plastic specifically 6 mil polyethylene plastic is.

After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. Polyurethane sheeting is a typical vapor barrier that contractors use to prevent moisture from penetrating the walls of a basement.