Resumen
This work shows the complexity of the assessment and verification of the constancy of performance of construction products. The results contained therein may constitute the basis for considering the need to change the criteria for assessing cementitious adhesives for ceramic tiles. The results presented in the article may also be the basis for the possible verification of legal requirements for the control of a construction product, which are cementitious adhesives for ceramic tiles, connected with the potential difficulties in a detailed assessment.