In this paper water storage parameters of hydrophobic plasters are determined. This article is focus on hygric properties of lime-metakaolin plaster connected with hydrophobicity. Most physic-chemical deterioration of building materials related to the penetration of moisture into building structure. Therefore, the aim of the testing was in description of influence of inner hydrophobic additive, which was applied to the interior structure of the element. Higher resistance of penetration water into materials show samples with hydrophobic additive. Water storage parameters are slightly better for plaster without hydrophobsation. However from the quantitative point of view the difference was not so important. Measurement involves not only properties of hydrophobic plaster, but comparative measurements with pure lime-metakaolin plaster were done as well.