Insulating Bathroom Walls Vapor Barrier

After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.

Insulating bathroom walls vapor barrier. Thus installing vapor barriers on wall surfaces must. Bathroom projects need special consideration because of the humidity and moisture that bathrooms generate. When moisture becomes trapped in walls mold and mildew can grow damaging your home and presenting a potential health danger. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets.

Install vapor barriers after the bathroom s plumbing electrical and insulation are complete. The science of moisture movement. Bathrooms and kitchens produce an enormous amount of water vapor daily. The materials that are most commonly used today for the installation of shower walls all either completely deter moisture penetration or encourage it to pass through a poor understanding of both could leave you with what is called a moisture sandwich.

Q a spotlight bathroom walls mold vapor barriers and building codes where s the love. Interior bathroom and kitchen walls for example are areas where there is great benefit to installing a vapor barrier. It will sit there like a sponge leading to mold problems and rot says tom. Whether or not you need a vapor retarder hinges on three main factors.

Is a building inspector justified in insisting the kraft paper facing be removed from fiberglass batt insulation because of mold potential or will that actually cause moisture problems. They are painted on surfaces and form a waterproof seal over drywall. Liquid barriers may also be used to prevent moisture from getting into the walls. Once insulation gets wet it s hard to dry it out.

Not every type of insulation needs a vapor barrier. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. You should only place a vapor barrier on the exterior side of the exterior wall allowing the assembly to dry back to the inside if water does get in past the tub surround. Vapor barriers sheets of plastic or kraft paper keep water vapor out of the wall cavity so the insulation stays dry.

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. In any case the vapor barrier must point to the warm side. Proper insulation will help keep your bathrooms a comfortable temperature year round. The industry standard as well as most local building codes do not encourage the use of a vapor barrier behind and over the tile substrate.