Comparing moisture meter readings with measured equilibrium moisture content of gypsum board: Fid-Bau Portal

Comparing moisture meter readings with measured equilibrium moisture content of gypsum board

Greenwell, Dale J. / Menetrez, Marc Y.

Moisture meters routinely used in the field to determine the moisture content in gypsum wallboard are primarily designed and manufactured to measure the moisture content of wood. Often they are used to decide whether to replace wallboard by determining if moisture is qualitatively higher or lower than another location. Because the moisture meter is so widely used, it is necessary to establish methods to ensure their usefulness and dependability as an aid in wallboard moisture detection and remediation. A method was developed to create a series of gypsum wallboard moisture content reference standards by exposing wallboard sample sections to static moisture content levels. Gravimetric analysis revealed good accuracy and precision of the reference standards to their theoretical values. A moisture meter was then compared against these reference standards to determine the meter's accuracy and precision. This study showed that the use of moisture meters might not reflect the actual moisture content within gypsum wallboard. This could be critical in the range below 1 % MC (moisture content), where the measured moisture content is used to determine the potential for mold growth or the application of surface treatments (i.e., paint). Continued work to fine tune the method is needed with emphasis placed on replicate sampling and the use of multiple manufacturer wallboard brands. Additionally, a field reference method is needed to support on-site moisture content measurements of gypsum wallboard using the current instrumentation designed for wood products.