There are many possibilities for a variety of ceiling designs, which vary depending on structural conditions. Examples for ceiling types are vaulted ceilings, concrete floors, carrier and beam ceilings. When choosing a ceiling type, the following criteria are crucial: The structural behaviour, the desired appearance, the total height as well as fire protection, sound insulation and other structural-physical aspects. Furthermore it needs to be considered which installations are meant to be placed in the ceiling. Materials used may be wood, stone, steel and aluminium, or various types of concrete.