Hygric properties of hydrophobized building materials

Vasilis Soulios*, Ernst Jan de Place Hansen, Hans Janssen

*Corresponding author for this work

Research output: Contribution to book/anthology/report/conference proceedingArticle in proceedingResearchpeer-review

31 Downloads (Pure)


Moisture loads due to wind-driven rain can lead to accelerated decay of exposed building façades. Hydrophobic impregnation reduces water absorption of facade materials and is thus presumed to decrease moisture related damages. Hydrophobic impregnation however also lowers the drying speed of the exposed facade, leaving mainly water vapour transfer to take place. This study examines the open porosity and capillary absorption coefficient of impregnated brick samples as well as the effect of hydrophobic impregnation on the vapour permeability of brick and mortar samples. The open porosity was measured with vacuum saturation test, the absorption coefficient was determined by water uptake tests, both done after one month of curing of the impregnated brick samples. The vapour permeability was derived from cup tests and from drying tests. The resulting open porosity from brick samples indicates that the changes in the overall pore structure are minimal after impregnation. In addition, the absorption coefficient of brick was found to be fairly close to zero, even with low concentrations of active ingredient, and regardless the percentage of silane/siloxane. Our findings support the claim that the hydrophobic impregnation does not influence significantly the water vapour permeability of brick and mortar
Original languageEnglish
Title of host publication4th Central European Symposium on Building Physics (CESBP 2019) : Prague, Czech Republic, September 2-5, 2019
EditorsR. Černý, J. Kočí , V. Kočí
Number of pages6
PublisherEDP Sciences
Publication date6 Sep 2019
Article number02048
Publication statusPublished - 6 Sep 2019
Event4th Central European Symposium on Building Physics 2019 - Czech Technical University in Prague, Prague, Czech Republic
Duration: 2 Sep 20195 Sep 2019


Conference4th Central European Symposium on Building Physics 2019
LocationCzech Technical University in Prague
Country/TerritoryCzech Republic
Internet address
SeriesMATEC Web of Conferences


Dive into the research topics of 'Hygric properties of hydrophobized building materials'. Together they form a unique fingerprint.

Cite this