# Humidity Conditions of Aerated Concrete Walls Depending on the Type of Finishing Coating
## 1 Introduction
Additionally, the scientific and technical literature suggests various compositions for exterior decoration of aerated concrete walls [16; 17; 18; 19]. In our study, we have developed a dry building mixture (DBM) specifically designed for finishing aerated concrete. This composition includes fluffy lime, aluminosilicate ash microspheres, white cement, an additive based on a mixture of hydrosilacites and calcium hydroaluminosilicates, ground waste from aerated concrete production, a plasticizer, a redesversible powder, and a water repellent. The resulting finishing coating, based on this composition, exhibits a thermal conductivity coefficient (which is a coefficient, reflecting the property of a material, to conduct thermal energy) \(\lambda\) = 0.137 \(\pm\) 0.007 W/(m\(\cdot\)C) (dry), an adhesive strength \(R_{\mathit{adg}}\) = 0.71 \(\pm\) 0.04 MPa, a vapor permeability coefficient (which is a coefficient, reflecting the property of the material, to conduct water vapor) \(\mu\) = 0.15 \(\pm\) 0.008 mg/(m\(\cdot\)h\(\cdot\)Pa), and a compressive strength \(R_{\mathit{c}}\) = 4.1 \(\pm\) 0.2 MPa [20; 21]. Also, an important advantage of the developed DBM should be attributed to the fact that its formulation uses ground waste from the production of aerated concrete. The efficient use of aerated concrete production waste will reduce the negative impact from its production on the environment. Due to the limited knowledge on the use of a DBM in various climatic conditions, it is important to evaluate the effect of the finishing layer on the moisture content of aerated concrete. In this study, we assessed how the characteristics of the exterior finishing coating and the density of aerated concrete affect the humidity regime for the walls of buildings located in different climatic conditions: Rostov-on-Don, Voronezh, Novosibirsk, and Vorkuta. During the course of the research, the temperature at the onset of condensation (\(t_{\mathit{b.c. }}\)), the amount of condensate falling out, and the percentage increase in the moisture content in the wall structure of the aerated concrete were determined. The work investigated the humidity regime in walls made of aerated concrete D350-600. This choice of aerated concrete density is due to the fact that aerated concrete of these grades is usually used in the construction of single-layer walls made of aerated concrete. It has been established that the use of a heat-insulating DBM contributes to a decrease in the temperature at the onset of condensation, a decrease in the amount of condensate,and a decrease in the increase in weight moisture W, %, in aerated concrete enclosures made of grades D350-600. This contributes to the preservation of the high heat-shielding properties of the enclosing structure made of aerated concrete during its operation. It also allows you to extend the service life of the exterior finishing coatings and increase the period of non-repair operation in buildings made of aerated concrete. The novelty of this research lies in the complex of findings obtained, reflecting the influence of the characteristics of the outer finishing coating, the density of the aerated concrete, and the climatic characteristics, on the humidity regime inside the outer walls. These findings from our study show the need for the careful selection of exterior finishes, taking into account all these factors. Also new is the method itself used for determining the amount of condensate falling out per year, taking into account the temperature at the onset of condensation \(t_{b,c}\), and the temperature during each of the months of moisture accumulation.