The damage caused to the walls by humidity is divided into two categories:

Direct damage can be summarized with the detachment of plastersstains and/or darker areas at all levels of the wall, stalactite formations in the under-face, detachment of wallpaper and coverings in general, unpleasant smells, the deterioration of the wall bodies and overall unhealthiness of the rooms.

Indirect damage can be summarized with: exposure of the walls to freeze-thaw cycles, internal and external condensationefflorescence and sub-florescence, the onset of molds, lichens and mosses, ignition of electrochemical oxidation and metal corrosion processes (with well-known degenerative effects on the structures), significant increase in the thermal conductivity of the walls with consequent equally significant losses in the degree of thermal insulation from the external environment.