The adverse effects of aggressive pollutants on the materials of the buildings are strengthened by poor maintenance. Lack of care of the roofs, eaves, horizontal insulation, etc., is a factor that makes it easier for water to exert damaging effects on the building materials irrespective of the concentration of atmospheric pollutants. Topcoats based on polymeric dispersions are used nowadays in the surface finishing of facades. The paper outlines the principal guidelines for their application.