Moisture buffer value of building materials

When building materials are in contact with indoor air they have some capacity to moderate the variations of indoor humidity in occupied buildings. But, so far, there has been a lack of a standardized quantity to characterize the moisture buffering capability of materials. It has been the objective of a recent Nordic project to define such a quantity, and to declare it in the form of a NORDTEST method. The Moisture Buffer Value is the figure that has been developed in the project as a way to appraise the moisture buffer effect of materials, and the value is described in the paper. Also explained is a test protocol which expresses how materials should be tested for determination of their Moisture Buffer Value. Finally, the paper presents some of the results of a round robin test on various typical building materials that has been carried out in the project.