The article considers the methods of rationalizing the process of heating the refractory materials of aluminum electrolyzers up in relation to thermal stresses arising in the hearth lining. The functional goals of the refractory materials are listed. The operational characteristics of the refractory materials are presented. During thermal influence on a hearth lining, the physical effects called thermal expansion occur. The materials which save their properties under high temperature are known as refractory materials. The thermostability is described in more detail. The scientific test bench was used to investigate ultimate strength. The method of temperature and pressure measurement when conducting the experiments is cited. In order to choose the potlining it is necessary to know the peculiarities of refractory materials and actual industrial loadings as precisely as possible.