Electrical impedance spectrometry (EIS) is applied for detection of humidity distribution throughout the cross section of autoclaved aerated concrete masonry constructions. It is a non-destructive method, which is easily applicable on-site and provides wide range of information about moisture migration through the cross section of a construction and about changes of materials porous structure. The particular research provides data about influence of direction in which the measurements are performed (parallel or perpendicular to supposed cladding direction) on the results of the frequency analysis and measurement values. All measurements are performed on autoclaved aerated concrete masonry blocks.