CELCRETE autoclaved aerated concrete (AAC) is a solid, inert, lightweight masonry building material that is suitable for use in both external and internal construction of all types of residential and commercial buildings. Used in conjunction with the CELCRETE building systems it enables most structural and insulation requirements of a building to be satisfied by a single material. It possesses excellent thermal and sound insulation and sound absorption qualities. It is fire and pest resistant and will not rot. Manufactured from sand, lime and cement, the addition of an air entraining agent produces a highly cellular material which is steam cured in high pressure autoclaves. It weighs about one-quarter the weight of standard concrete and can be cut, drilled, channeled and shaped on site using conventional hand or power tools.