Linear-Regression-Equation-Based Prognosis of the Dependence of the Thickness of the Air Layer Equivalent to the Paint Coating’s Water Vapour Permeability on the Type of the Paint and Number of the Paint Coating Layers

  • Jolanta ŠADAUSKIENĖ∗, Raimondas BLIŪDŽIUS, Rita SPEIČIENĖ, Vidmantas DIKAVIČIUS Kaunas University of Technology
Keywords: painted thin render, water vapour permeability, water vapour resistance factor, air layer thickness equivalent to water vapour permeability, moisture state.


For the wall’s moisture state calculations it is important to know the values of the water vapour permeability parameters
for the materials of which the wall layers are made. Therefore, if the exterior layer of the wall is painted repeatedly then
the vapour resistance value of total paint layers do not conform to the declared values. Hence the aim of the paper is to
the determinate the correlation between the number of the paint coating layers and water vapour resistance by presenting
the linear regression equation that can be used to predict the value of the paint coating’s vapour resistance factor in
relation to the number of the paint coating layers. The results of calculation show, that the sd value of the paint coating
depends on the type of paint and the number of the paint coating layers n. The major inadequacy of the sd value is
determined for the acrylic paint.