Moisture movement in double layer building materials

To prevent the problems of internal condensation inside building walls, it is necessary to predict the moisture behavior exactly not only in the hygroscopic region of moisture content but also in the non-hygroscopic region. The purpose of this study is to understand the behavior of condensation in building materials. For a single layer wall, which consists of a single material, previous studies have been done by a variety of authors. But considering that an actual wall is multi layered and consisting of several kinds of materials, the analysis of moisture movement in a multi layer wall is necessary. In this paper, double layer wall, which consists of two kinds of materials, is considered. The change of internal moisture content in the wall under the condensation process is measured and analyzed by numerical calculation using two models. Firstly, specimens of a double layer wall are assembled. The changes of moisture content of specimens in the condensation process are measured. Next, the change of internal moisture content in that process under the experimental condition is calculated using two models. Both results are compared and the mode of internal moisture transfer calculation is discussed.