Water in building materials not only influences important physical properties and chemical processes but is also related to the well-being of the occupants of a building. The drying of cementitious materials is complex, involving several different drying processes. The conditions for each drying process change as the material changes its properties as it goes from a particle suspension in the fresh state to a fine porous material in the hardened state. The present article describes and quantifies the drying processes of cement-based self-leveling flooring compounds (SLCs) and relates them to the extent of reaction, which here is quantified by isothermal calorimetry. The relative importance of the different drying processes is discussed and a model for the drying of the SLCs is proposed.