The article describes the performance properties of highly filled polymer-fly ash mineral composite based on polyvinyl chloride which affect the durability of construction outdoor products. The article presents the results of studies to determine the coefficients of thermal expansion of polymer-based composite mineral, filled with PVC TPP fly ash, to accelerate climatic tests, sample stability to UV radiation. The purpose of this is to predict the service life of products made from this material. We came to conclusions that the layered structure, technological parameters of production and the amount of filler affect the coefficients of thermal contraction - expansion of the material, i.e. material shrinkage along the length and width and increase in thickness at the temperature changes from 40 to 80 °. It was found that the use of heat energy waste, namely, fly ash CHP as a filler in PVC compositions, not only enhances the mechanical properties of the material, but also improves the set of properties which affect the service life of polymer- mineral composite products.