Production of autoclaved aerated concrete (AAC) from power industry waste cinders represents a progressive technology for processing of industrial waste in a new form of building material with good qualities. Despite these positive aspects, the share of cinder concrete in the building industry is less popular. The low popularity is partially caused by the poor aesthetic of cinder concrete in comparison with sand-based AAC; however, the main cause is the slightly smaller thermal and moisture qualities of fly ash-based AAC, respecting uncertainty because there are no supporting scientific research and publications about it. This paper is dedicated to a study of the thermal and moisture properties of the cinder concrete and mutual behaviour with the sand-based AAC. It was determined that fly ash-based AAC demonstrated slightly larger moisture sorption in comparison with sand-based concrete under similar conditions. On the contrary, the thermal insulating properties of fly ash-based concrete, as indicated by the heat conductivity, exhibits less moisture influence in comparison with sand-based AAC. Concerning volume changes, fly ash-based AAC showed, in the condition of low moisture, slightly better properties when compared with autoclaved aerated sand concrete. (C) 2012 Elsevier B.V. All rights reserved.