One of the methods used to reduce the impact of water on building objects is hydrophobisation. This article presents the analysis of the efficiency of hydrophobising preparations based on silica-organic compounds with a high concentration of organic solvents due to their increased hydrophobic potential, compared to water based preparations. The testing materials were ceramic bricks. The following parameters were tested: water drop absorption coefficient, contact angle and surface free energy, surface water absorptivity, water vapour diffusion ability, water vapour permeability, thermal conductivity coefficient, as well as silicon resin distribution in the micro-structure of a ceramic brick. Based on the obtained results, the efficiency of hydrophobisation using the high volatile organic compounds (VOCs) content emulsion was analysed. The surface free energy (SFE) of the impregnated samples was 4.5-5.2 times smaller than in the case of the standard samples, which indicated a very good hydrophobicity of the bricks using the high VOC content emulsion. (C) 2015 Elsevier B.V. All rights reserved.