Defects in the finishing coatings of building structures are one of the most common problems faced not only by developers, but also by residents of new buildingsin the initial period of their operation. This work is devoted to establishing the causes and mechanisms of the occurrence of destructive processes in the interiordecoration of interior partitions made of tongue-and-groove gypsum boards, an apartment building with a monolithic frame, which appeared a few months afterthe completion of the plastering work. To solve the set goal, the authors used an integrated approach, which included a constructive, materials science, andorganizational and technological aspect. It has been established that large-scale self-destructive deformations of the plaster layer are caused by intense movementof water vapor from the porous base of the slab after turning on the heating in the premises, and the movement of steam was prevented by an incorrectlyselected multi-layer finishing coating, which has less vapor permeability than a gypsum tongue-and-groove slab. Excess moisture in the porous structure of theslabs appeared as a result of its capillary suction from cement-sand screeds, which were laid at this facility after the installation of internal partitions, that is, inviolation of existing regulatory requirements.