Moisture Control: Utilizing Vapor Retarders
A vapor retarder is defined as a material or system that adequately retards the transmission of water vapor under specific conditions. Building occupants, certain appliances, plants, and plumbing equipment generate moisture that is carried in the air as vapor.
Moisture control through limiting water vapor movement in commercial buildings is essential. A vapor retarder helps prevent water vapor from moving into building assemblies, like walls, where it can condense into liquid water within the structure. Liquid water can accumulate inside exterior walls and in roof and crawl spaces. If enough water is present, rot and decay can cause significant damage. The kraft facing on insulation with an asphalt coating serves as a vapor retarder. The vapor retarder can reduce the likelihood of condensation within building walls, floors, and ceilings.