Vapor barrier is a specialized category of building materials designed to control the movement of water vapor through walls, floors, and ceilings. These barriers play a crucial role in protecting buildings from moisture-related problems such as mold, rot, and decay. Essentially, a vapor barrier acts as a shield that prevents water vapor from penetrating into the interior of a building, while allowing air to flow freely. They are typically made of high-density polyethylene or other impermeable materials, and are installed between the insulation and the interior wall or ceiling surface. By preventing moisture from entering the building envelope, vapor barriers help to maintain a comfortable and healthy indoor environment, while also protecting the structure itself from damage. Whether you're building a new home or renovating an existing one, a high-quality vapor barrier is an essential component of any moisture control strategy.