Technology of Additional Impermeable Layers and Its Use in Restoring of Historical Buildings

Abstract

Abstract Moisture and its negative effects on monuments are a widespread problem that needs to be tackled especially to save historical buildings. The moistening of objects, whether historical or new, is not only part of our climate zone, but can be attributed to a global character, as evidenced by a number of publications and research on the issue of water logging of buildings that date back to 1892. It is not only a threat to the preservation but also the functionality of historical structures, because it is responsible for reducing the mechanical performance of the masonry, as the presence of water in the pores of the building material negatively affects the tensile strength and also the compressive strength. It also causes degradation of these materials, which can be constantly exposed to cyclic freezing and subsequent thawing, biodegradation and migration and subsequent crystallization of salts. Moisture also contributes to increasing the thermal conductivity of these constructions, resulting in high energy consumption for heating. Last but not least, we can associate various respiratory diseases of people living in this environment with moisture. Due to the serious effects associated with rising damp in the masonry, water capillarity is rightly considered a key factor in the protection of heritage. The origin of moisture can be attributed to several facts, but in the present research we focused mainly on rising damp and its negative impact on historical structures. The paper will summarize the results obtained so far and conclusions from various authors investigating the technology of additional impermeable layers. Subsequently, we will analyze and describe the obtained measurement results before and after the use of undercutting technology on two specific historical buildings in Slovakia. All the research and measurements were carried out in situ, which helped us to achieve objective results, the outcome of which is this work. The measured values show a significant drying of the structure above the plane cut and a positive effect on the repaired structure. The research also encourages further investigation of moisture acting mainly below the level of new insulation and its impact on masonry.