Physical wear and tear can be determined either by studying with the help of instruments, or relying on regulatory and expert methods. The first helps to obtain reliable indicators of physical wear, but to obtain it requires less materials. Normative and expert methods - the second make it possible to identify the degree of wear with less accuracy, but it requires a small investment of materials and time. Two similar methods include the "Methodology for determining the physical deterioration of civilian buildings", which was created by MINKOMHOZ of the RSFSR, as well as Departmental building codes 53-86 (r) "Rules for assessing the physical deterioration of residential buildings." The problem of lack of information in the absence of the possibility of personal inspection of the evaluated structure, and, in addition, the obsolescence of the methods makes it difficult to use them. In this case, it is logical to use calculation methods.

Keywords: corrosive wear; reliability; durability; classification