Experimental investigation of moisture properties of historic building material with hydrophobization treatment

Moisture has a great impact on the building performance. Moisture accumulated in the building facade can lead to frost damage, mould growth, condensation, and decrease of thermal resistance, which reduce the sustainability and durability of the building structure. Wind-driven rain is one of the most important moisture sources affecting the building facade. Hydrophobization treatment on the exterior surface of the buildings with the water repellent agents can effectively reduce rain absorption and penetration. This is especially important to renovate the historic buildings, for which the exterior appearance needs to be conserved. In this paper moisture properties of the building bricks from a historic building before and after the hydrophobization treatment were experimentally investigated. The building bricks were impregnated in the water repellent agents with different concentrations of the active ingredients. Water absorption test and water vapor diffusion test were conducted to observe the influence of the hydrophobization on the moisture transport behaviors of the brick. The results are beneficial for the researchers to find the optimal solution to improve the hygrothermal performance of the building facades. (C) 2017 The Authors. Published by Elsevier Ltd.