Expanded clay blocks are an emerging trend in the construction market. In an era of high natural gas prices and problems with the availability of this raw material, prefabricated expanded clay blocks are an alternative to gas concrete products, among others. Keramzite concrete materials are characterized by high sound insulation and vapor permeability. Keramzite concrete blocks and blocks do not show capillary rise and are characterized by low diffusion resistance. In this respect, expanded concrete blocks distance the competition by showing nearly three times higher vapor-permeability than aerated concrete products.