High Quality Content by WIKIPEDIA articles! High Quality Content by WIKIPEDIA articles! Stucco or render is a material made of an aggregate, a binder, and water. Stucco is applied wet and hardens to a very dense solid. It is used as a coating for walls and ceilings and for decoration. Stucco may be used to cover less visually appealing construction materials such as concrete, cinder block, or clay brick and adobe. The difference in nomenclature between stucco, plaster, and mortar is based more on use than composition. Until the later part of the nineteenth century, it was common that plaster, which was used inside a building, and stucco, which was used outside, would consist of the same primary materials: lime and sand (which are also used in mortar). Animal or plant fibers were often added for additional strength. In the later part of the nineteenth century, Portland cement was added with increasing frequency in an attempt to improve its durability. At the same time, traditionallime plasters were being replaced by gypsum plaster.