Design of ceramic tiles with highsolar reflectance through the development of a functional engobe

Roofing solutions with high capacity to reflect incident solar radiation, the so-called cool roofs, can provide an effective answer to summer overheating of either individual buildings or whole urban areas. Nowadays, commercial cool roofs products are mainly represented by organic membranes and coatings, but ceramic tiles can represent an interesting alternative or complement in view of their low maintenance cost. In this work, it is illustrated how a high reflectance engobe can affect in a positive way the solar reflectance of a glazed tile thanks to the introduction of suitable raw materials and pigments. The reflectance was in fact found to be affected by either the support, the mineralogical composition, the engobe thickness or the glaze. The procedure through which the glazed tile is developed and tested is discussed, in the perspective of production through commonly used industrial processes.