Non-metallic building structures nondestructive examination methods using is an essential requirement for conducting a technical inspection of existing constructions. The technique of applying the nondestructive examination method for thermal control of one of the most common constructions of hydraulic structures – reinforced concrete fastening slopes of ground facilities (dams, canals, etc.) is considered in this article. The aim of this method is to identify areas of slabs, detached from subgrade. It is shown that the optimal decision includes synchronized analysis of the thermograms and the visible areas of the slopes detachment recording. This decision reduces the number of the thermal field areas false anomalies caused by the local features of concrete surface layer and by background effects. During the results analyzing false anomalies of the constructions thermal field areas must be considered and rejected. These anomalies can be related with the concrete surface layer condition or the proximity of masking factors: water, vegetation, etc. In the example of full-scale 6.8 km long dam examination the false thermograms anomalies were more than 50% from the total number of tested plates.