Determining the Water-Vapor Permeability of Common Wall Materials

摘要

In most building materials, heat and moisture trans- fers and air movement are interrelated, and heat and moisture transfers through those materials occur together in most buildings. The effectiveness of a vapor retardant depends both on its permeability and whether it's installed properly. For these reasons, it's important to know the properties of the materials you plan to use in a building envelope. With this in mind, Jerry M. Sipes, Ph.D., PE, and Mohammad H. Hosni, Ph.D., designed an experiment and tested how permeable several common wall materials were at different levels of relative humidity. In an environmental chamber with a constant temperature (25℃ ± 0.5℃, or 77℉ ± 1℉), they carefully controlled conditions to ensure the soundness of their test results on plain gypsum board, latex paint, permeable vinyl wallpaper, heavy vinyl wallpaper, and elastomeric stucco.