Lately, IR thermography is frequently applied for important purposes in monitoring buildings such as energy leaking, ventilating and air-conditioning installations, electrical and mechanical installations, moisture detection etc. Nondestructive monitoring methods are essential in case of monitoring historical buildings. It is curtail not to destruct any part of the buildings, which are historically important. Therefore, nondestructive methods need to be used while monitoring this kind of buildings. In this study, IR-Thermography was used in order to distinguish different construction materials that were used to build the walls of a historical building. The thermal monitoring was made with Optris PI-450 long wave infrared camera. The results showed that IR monitoring can be useful to distinguish the building materials without destroying the investigated buildings' plaster or facing. It is observed that the best results can be achieved on higher temperatures at IR-Thermography.