Plastering—Why a Waning Craft?
IN THE City Hall of Portland, Oregon, it looks like marble. At Trader Vic’s Restaurant in New York city, it resembles bamboo. And in the palace at Versailles, France, it depicts human figures, cupids and flowers. What is it?
This remarkable material is plaster, initially a liquefied substance with no form of its own. And the ancient craft involved is plastering, the art of applying plaster to cover and decorate walls and ceilings.
Plaster, when mixed with water, can be poured and cast, colored and textured, troweled and polished. For that matter, when it sets and hardens, plaster can be carved like stone. No wonder William Millar wrote: “Plaster is the most vigorous as it is the oldest vehicle for carrying down generation after generation the masterpieces of art”!
Amazingly, though, the use of plaster has diminished. Whereas it once had a worldwide dominion, today artistic plastering no longer is called for to any great extent. Now plasterers in many lands work according to strict production timetables, applying their mortar with large pumping machines to make plain, flat wall surfaces for our modern buildings.
Yes, even as a simple wall covering, the popularity of plaster has waned. It is estimated that, back in the 1920’s, more than 95 percent of all newly constructed homes in the United States had interior coatings of plaster. Today, however, this has fallen to roughly 5 percent.
Why the decline? A close look at this ancient trade should give us the answer.
An Elaborate Trade
The word plaster, taken from the Greek, literally means “to daub on.” But that brief definition should not make you think that plastering is a slapdash, or haphazard, trade. A “menagerie” of trowels, straightedges, molds, floats and other tools must be “tamed” and mastered before one can be considered a journeyman plasterer. In times past, an apprentice would be indentured to a master plasterer for up to seven years, receiving room, board, clothing and other necessities as pay. Little wonder that some plasterers then knew sculpturing, casting, modeling, elaborate texturing and other phases of the trade not commonly used today.
Even making plaster from raw materials was within the plasterer’s scope. In the early days of America, for instance, it was common to see kilns cut into Pennsylvania’s hillsides, stoked and tended for the burning of limestone and gypsum, basic ingredients for lime and gypsum plasters. Today the process has been improved in large factories, but the production steps remain the same.
The heat of the kiln breaks down gypsum’s chemical composition. Then the calcined or burned gypsum is ground to a fine, white powder. Finally, depending on the fineness of the powder, the degree of calcination and other characteristics, this plaster can be used as a casting plaster for statuary and fine artwork, or it can be mixed with sand and other ingredients to make other types of plaster. One of the most widely known materials is plaster of Paris, a quick-setting gypsum plaster made for patching and repairing walls.
Limestone, however, requires an additional step after calcination and grinding before it is suitable for use. Water is carefully added in a process called hydration or slaking. Then the hydrated limestone, now called lime, is ready to be mixed with other ingredients at the job site. Lime plaster, with some gypsum mixed into it for setting purposes, is most commonly used today as a thin interior finish coat.
Only in the last century has there been a major addition to these two basic types of plaster, with the introduction of Portland cement plaster. Because it prevents almost all water penetration, it makes an excellent stucco, that is, exterior cement.
Many Uses in History
Perhaps you are not aware of the honorable mention that plaster has been given in the pages of history. Well, plaster was known to the early Hebrews and the Babylonians. (Lev. 14:42; Dan. 5:5) Some say the Greeks were the early perfecters of this ancient trade, diligently finishing their “stucco duro” so well that onlookers could see their own reflections in the walls. Slabs of Greek plasterwork were even used for tables and mirrors.
But as far as ornamentation is concerned, the Italians brought plastering to its noontide glory during the Renaissance. Imagine touring a palace built at that time.
As you walk in, feast your eyes on the grand display of plasterwork. Projecting ribs—tastefully dressed with leaves, vines and other plant forms cast from plaster—divide the lofty ceiling into rectangular and circular compartments. The building abounds with plaster formed into panels, shields, bands, ribbons, roses and wreaths of flowers. Walk through various rooms and courtyards and you see plastered motifs, exquisite friezes, cast statues, stucco fountains—all of these making the palace a plasterer’s showplace.
Yes, the Italians loved to embellish their buildings. They were careful, however, to keep secret their wonderful recipes and techniques. But secrets do leak out! Probably no one came across a more fundamental and important one than an English architect traveling in Italy during 1851.
The Secret of Plastering
The Englishman was impressed with the fine lime that an elderly Italian was using in repairing some ornamental artwork in the Campo Santo at Pisa. But it was only after some persuasion over a bottle of wine that he finally convinced the old man to divulge the secret formula for his lime.
The Italian led him to the remnant of an old palace, down to a musty cellar, and to a row of wooden barrels. Taking a key from his pocket, the old man tapped the first barrel. It gave a hollow sound until the key nearly reached the bottom. “There, signore!” he said. “There is my grandfather! He is nearly done for.” At the next barrel he tapped in the same manner. “There, signore! There is my father! There is half of him left.” The third barrel was nearly full. “That’s me!” he said proudly as he wheeled around with a finger to his chest. And at the last barrel, the old Italian could not hold back his chuckles at finding it more than half full. “That’s for the little ones, signore!”
Puzzled by all of this, the architect pressed for an explanation. These barrels, explained the Italian, contained aged lime made from burning fragments of white marble statuary, the purest form of limestone. The lime was slaking slowly in the moist cellar air. This was the family treasure—lime received from the man’s forebears and now passed on to his sons.
The Englishman was delighted to learn this because plasterers in the rest of Europe were not aging their lime in this manner. But something far more significant impressed the Englishman. Among the Italians, plastering was more than just employment. It was a family heirloom. The best recipes and techniques had been carefully passed down from father to son.
It was in this kind of climate that plastering flourished. But what brought about its decline?
The Economic Factor
Probably no one realized how far-reaching would be the effects of the Industrial Revolution, which began in England during the 1600’s and eventually swept across much of the world. Who would have thought that cherished family trades, such as plastering, would be forsaken for production-line factory jobs? But that is what happened, for the factories offered quick monetary returns, and little training was needed.
Then came World War I. Industry geared itself for producing weapons and machinery, dramatically exhibiting the economy of standardization and mass production. Due to a shortage of craftsmen, rising wages, inflation, improved factory production methods, and for other interrelated reasons, buildings began to be put together differently. Construction techniques became a process of timesaving assembly rather than artistic craftsmanship. All of this contributed to extreme simplicity of design. Gone were the ornamental ceilings, the cornices, the embellishments.
Gone, too, was general dependence on artists and skilled craftsmen. In time, substitute wall coverings, such as paneling and drywall (a paper-lined artificial board made from gypsum), largely replaced plaster because of their lower cost and easier installation. Referring to a ten-year period ending in 1969, Walls & Ceilings, a journal favoring the plastering industry at the time, said: “One particular field, Drywall, has increased in use 1500 times [meaning percent] over our product in spite of millions of dollars of promotion money spent by our industry.”
Why such a dramatic increase? Robert L. Whittle, as cochairman of the International Wall and Ceiling Contractor’s Technical Committee, answers: “High wages and limited use of conventional plastering has all but destroyed the industry. The cost of hand-applied mortar with wages in excess of $80 per day over most of the United States has transformed one of the less expensive construction finishes to a luxury few can afford.”
Nonetheless, efforts have been made to lower the cost. Instead of the traditional method of hand-applying mortar, large plaster “guns” now spray on the mortar while workmen follow behind, straightening and leveling it out. Additionally, lightweight plasters and special acoustic plasters have been developed. There have been other significant advances, too. High-density veneer plasters, spread over a drywall-type base in one thin coat, showed a 30-percent increase in 1975 over the year before, and their use grows each year. Many look to this as a lifesaver for the plastering trade.
Advantages and Disadvantages
Yet, there is a factor that is surprising to some persons. Studies of wall coverings have shown that when the initial cost, the maintenance expenses and the usable lifetime of plaster are compared with its substitutes, conventional plaster usually turns out to be more economical.
If so, why is it that plaster is not used more often? Simple. Substitutes cost less initially. They take less time to install. Builders of high-rise apartment houses also find that the newer, lighter materials save on structural steel. And these materials allow more flexibility in renting space, for the walls can be altered and rearranged with less trouble than if they were made of plaster. Without a doubt, modern methods offer significant advantages.
But there are disadvantages, too. Many have lamented the loss of quality and craftsmanship in modern buildings. Nowhere is this more evident than in public buildings. Older structures, complete with plaster ornamentation, are being replaced with larger buildings that often have less architectural appeal.
Note the 1910 Hudson County Courthouse in New Jersey (U.S.A.), replete with rotunda and artwork throughout. In 1966 it was replaced with a large office-type building, concerning which the New York Times Magazine says: “The new building cost $14-million and the old one was built for $3-million, which says a lot about soaring costs. The $3-million bought Italian green and pearl gray marbles [including ornamental plasterwork]; half a century later, $14-million bought paper-thin veneers, plastic, and aluminum that looks like tin.” Scores of examples like this could be cited.
This is not to say, of course, that modern buildings—whether containing drywall, the latest plastering materials or other wall coverings—are always of poorer quality than those of the past. Many look on the new architectural styles with favor, seeing them as improvements to the overwrought ornamentation, the “gingerbread,” of some of the older styles. And many persons benefit from the cheaper housing that present-day architecture can provide.
But whatever is our view of modern construction, we can look with appreciation at the quality plasterwork of the past, knowing it will never be duplicated to any great extent under the present economic system. Though a waning craft, plastering still remains one of the greatest building skills.