Retention curve is the basic material property used in models for simulation of moisture storage in porous materials. The measurement of retention curves (also called suction curves, capillary potential curves, capillary-pressure functions and capillary-moisture relationships) is described in this paper. The water storage of different types of sandstone, the materials frequently used on the Czech territory for many centuries mainly for architectonic details and sculptures, is studied in using pressure plate apparatus. The obtained data gives information on materials behaviour in contact with liquid water and on their absorption capacity.