Insulating Interior Walls Vapor Barrier

Without poly beneath the drywall water vapor hits the drywall and diffuses through to the drier in summer indoor air.

Insulating interior walls vapor barrier.

Whether or not you need a vapor retarder hinges on three main factors your climate your home and the location of the wall you re insulating. In any case the vapor barrier must point to the warm side. During the energy crisis of the 1970s a prevailing belief took root where it was thought that tightly sealing walls and ceilings with a vapor barrier was essential to blocking heat transference and reducing energy costs it was soon determined however that unless the seal was absolute moisture that did get into sealed walls could create serious structural problems and health issues such as. A vapor or moisture barrier is a layer of protection that is designed to act as a waterproof shield helping to keep condensation away from wood insulation and other mold prone materials that are located behind the drywall.

Vapor barriers when to use them when to not. The presence of an interior vapor barrier makes drying out the cavity harder to do though. On this special edition of the build show matt takes us on a guided tour through the ins and outs of vapor. To know if you need a vapor retarder ask yourself a few basic questions.

The headline of your question is insulating an old house with no vapor barrier perhaps the first thing you need to know is that the presence or absence of an interior vapor barrier is irrelevant. The place to control vapor migration is on the exterior of the basement wall in the form of waterproofing or damproofing. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. On the interior the best insulation to place against the concrete or block is rigid foam without any facing such as foil or plastic sheeting.

Interior bathroom and kitchen walls for example are areas where there is great benefit to installing a vapor barrier. Bathrooms and kitchens produce an enormous amount of water vapor daily. If you want a vapor retarder on the interior side of your walls you can always apply vapor retarder paint. The short answer is no you generally do not want a vapor barrier on the walls of a finished basement.