Before sheetrock, there was plaster. Like most industrial housebuilding materials, sheetrock is a recent invention. Before World War II, the majority of American houses were plastered. Before the 20th century, plaster was the standard interior finish. In many parts of the world, it still is. Plaster is made from either lime or clay (or both) mixed with sand and fiber–traditionally animal hair, but now more often straw or hemp. Unlike sheetrock, it can be applied to a variety of building materials, such as cob, straw bales, or the standard for wood buildings, wood lath. Plaster can be a finished wall surface on its own. Earth plasters are often mixed from particularly attractive clays and left "unfinished." Chopped straw can offer subtleties of color and texture. The wall texture itself can be altered by a variety of techniques applied to the finish plaster, such as hard troweling, burnishing, or sponging. Whatever the finish technique chosen, a plastered wall always delights the eye with slight, but infinite variations in texture and color. Plaster accommodates itself to the design, rather than the design being limited by the material. With plaster there's no waste at all, since only enough is mixed to plaster the job at hand. Any small leftovers are reusable. Plaster is also extremely adaptable to non-standard or unusual design features, such as plastered window reveals or exposed timbers as in the pictures above. And perhaps most comforting, plaster is made from simple, natural materials: clay, lime, sand, straw.
