The present paper provides an analysis of the existing dependencies describing the kinetics of fluid capillary rise in porous materials on the basis of the ideal model and on the basis of mercury porosimetry data; it also determines and describes the factors related to the deviation from the approximated experimental data (the discrepancy between the predicted values and the experimental data). A dependence for determining the pore hydraulic radius in the ideal model was obtained from the condition of the identical kinetics of capillary water rise in both the actual material and in its model. A method was developed of assessing the hydraulic radius required for determining capillary moisture transfer in shielding structures which takes into account the effect of narrowing and widening of capillaries, the effect of the temperature rise related to water vapour sorption and the effect of changes in water viscosity. (C) 2015 Elsevier Ltd. All rights reserved.