The change in the dimensions of the wood-cement composite, which takes places during drying and wetting is an extremely important due to the application of the wood-cement composite. In this work, the dew point temperature was determined in order to establish the precision of the hygrometer in determining air humidity, and the change in the dimensions and mass of the wood-cement composite before and after drying and wetting process. The measurements were carried out in the laboratory using the resistance method for determining the dew point temperature, the dryer and a micrometar. In the experimental part, an apparatus for determining the dew point temperature was constructed based on the resistive method of determining the dew point temperature, by monitoring the resistance change on the sensor detector via the CNY 70 optical sensor. Then the dimensions and mass of the wood-cement composite were measured during drying process. Eksperimental data for determining the dew point temperature confirmed the precision of the apparatus due to the remarkable accuracy in results of relative humidity in comparison to the values detected by the hygrometer. When testing the changes in mass and dimensions of the composite, the dana for monitoring the change in mass were modeled according to one-phase exponential decay model: y=A1*e^(-x/t1)+yo, and there is a noticable link between the initial dimnesions of the composite and the change of mass and amount of absorbed moisture. Dimensional changes are depend on the thickness of the wood-cement composite, which has an impact on its properties.