Hygrothermal Performance Difference of Wooden Beam Embedded in an Internally Insulated Masonry Wall in 2D and 3D Models

Abstract

Internal insulation of masonry walls may significantly increase the decay risk of embedded wooden beams due to lower temperature and consequently lower drying potential in the existing wall. Since high moisture contents will affect the performance and service life of wood, the study of moisture-related damage problems in wooden beam-ends in internally insulated masonry walls is of great importance. In the previous studies, the numerical study of hygrothermal performance of wooden beam-ends is performed only with 2D models. In this paper, we study whether a 2D numerical model can represent accurately the 3D hygrothermal behavior of wooden beam-ends. Therefore, the difference between 2D and 3D model results of the hygrothermal performance of wooden beam-ends embedded in an internally insulated masonry wall is analyzed. The difference of temperature and relative humidity in wooden beam-end between 2D and 3D models is in general small. However, 2D hygrothermal models show much lower relative humidities and thus lower moisture risk at some locations in the wooden beam-end. We find that a 3D hygrothermal model more accurately simulates the hygrothermal behavior.

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