Rising humidity in old and historical buildings is a current issue that affects their structure, due to water capillarity and its propagation inside the walls, a key factor in heritage preserving and its functionality. It is also responsible for materials degradation exposed to frost and defrost cycles, biodegradation and salt crystallization. Moisture also increases the heating costs of the affected buildings, due to high thermal conductivity of the moist masonries. The paper presents an unconventional method for humidity removal or stabilisation due to infiltration of capillary water into the masonries, using electromagnetic waves systems that result in changing the water polarity inside the affected walls and pushing it out of the construction. The system consist of a small box, connected to the power supply, installed inside the building, remaining on the same location throughout the entire life of the construction. By means of this procedure, not only do the walls of the structure stay moisture-free, but also the foundations and the surrounding soil. Through this process, not only the walls of the construction remains dry, but also the foundations and the soil around them. The electromagnetic wave method was applied on five different historical buildings, located in Romania, Cluj Napoca’s historical centre, in the vicinity of Somes river, with rising damp due to water capillarity. Measurements were conducted at every six months after the system installation, for a period of minimum 24 months, using the same marked locations, at a depth of 5 cm in the walls. All buildings studied are made of stone and stone with plain brick, with different chemical, type, pore direction and porosity characteristics. The measured values show in most cases, a clear decrease of wall humidity levels or a stagnation of the capillarity rise in the monitored walls, after a minimum of 24 months after the system installation. The electromagnetic wave system, as a non-destructive method, can be applied to cases with no accidental water source or high raised groundwater, for historical buildings where no exterior works are possible or interior invasive interventions.