|The History of Plaster
The earliest evidence of plaster use can be found in the homes of primitive man, mostly because the basic materials are all natural ingredients. Archaeologists have uncovered clues showing that the early structures of ancient humans consisted of mud plastered over reed and stick enclosures in order to seal crevices. This added protection from elements and other dangers.
After mud, we see lime, sand and gypsum as the oldest forms of material being used. For example, the buildings of the ancient Egyptians, Greeks, and Romans all show the use of lime based plaster. Ancient tools found in Egypt show that the Egyptians first applied plaster to their walls over 4,000 years ago and the Greeks have used it since at least 500 B.C.
The Greek historian Theophrastus (371-287 B.C.) even described the making and application of plaster in his writings. In fact, it is from the Greek “emplastron” that we derive the name. An advance in architecture was taken around the 4th century B.C. when the Romans discovered the principles of hydraulic lime, which allows plaster to solidify rapidly (even under water), by adding volcanic ash to the composition. Furthermore, new discoveries of intact plaster walls, many with beautiful frescoes, are continually being found, giving us a peek into ancient life and illustrating the use of plaster during that time. These ancient people used plaster because it was a strong building product and created a beautiful finish.
During the Middle Ages, plaster continued to be valued as a building product. It was recognized as a fire retardant and after the 13th century, many buildings in England were required to have plastered walls by order of the King for safety reasons. The renaissance period saw plaster developed to its zenith. The smoothness of plaster walls proved to be a good medium for artistic works. During this period, we see an abundant use of decorative plaster. You may recognize a few of the famous buildings constructed with plaster during this time such as St. Peters Basilica and the Sistine Chapel in Vatican City as well as the Florence Cathedral in Italy.
The constructional value of plaster has endured even to the present, albeit with a few new changes and discoveries. For example, Keanes cement, a slow setting (but extremely hard) plaster, and metal lath were introduced during the 1800s. In the 20th century, Gypsum plaster (previously reserved only for ornamental work due to its high cost and fast setting time) gradually replaced lime as the primary binding agent. Even today, new developments in modern technology continue to change the plaster industry. For instance, polymers able produce superior bonding and weather resistance have been created and are sometimes used as an additive.
However, although changes have been made and products improved, it is important to remember that the basic plaster recipe, handed down from generation to generation, has not drastically changed. This continuity has allowed plaster, beautiful and enduring, to persist in popularity in its use in our homes and buildings. Indeed, plaster itself holds a place in our history.