Moisture Transfer Through Materials and Systems in Buildings

When many of the current moisture control design guidelines for buildings were developed 50 years ago, they were consistent with analytical approaches and test methods. This consistency deteriorated when the importance of air convection was recognized. Although considerable research on moisture problems in buildings is available, there is no general consensus aimed at prevention. Sophisticated analytical moisture models have been developed, but they are not easily available or are too complex to use as analytical or design tools. Current water vapor transfer test methods do not provide material property data for these models or for design practice.

To restore consistency and make this information more useful to building practitioners, a coordinated approach to mathematical modeling is needed. Practical analytical tools need to be developed and test methods need to be expanded or developed to yield data appropriate for these models. Finally, more detailed information about airflow patterns in building components needs to be obtained.