Abstract. The article presents the results of calculating the reliability of enclosing structures of filling station buildings. The aim of the work was to determine the optimal number of inspections of technical condition and to estimate the cost of the operation of the sandwich panel. The problems of searching for hidden failures were analyzed. An overview of the causes and mechanism of wetting the structure was made. An example of a logical-probabilistic structural model for computing the operability for increasing the operational usability of multilayer structures is given. A mathematical model was proposed for determining losses in the selection of various maintenance strategies.