The outer walls of the bath need to be plastered, painted or covered with finishing siding, which will not miss moisture into aerated concrete. The structure should not be insulated strongly, since the blocks retain heat well. Blocks have a cellular structure and consist of cement, sand and water. All these materials are harmless to human health, retain heat well and will last a very long time. The economy of this material is well known, but when buying, you should pay attention to the density and appearance of the blocks. High -quality blocks have a high density, even color, the same size and even structure.