The History of Drywall
Drywall is an invention of the 20th century. Today, it is an essential part of residential and commercial construction. When was drywall invented? How did it take over as the industry standard?
Before drywall, there was plaster
Plaster has been around for thousands of years. The ancient Egyptians burnt gypsum in open air fires to produce plaster. The Greeks and Romans used plaster for architecture and decorative sculpture. Plaster sculptures were found when excavating the ancient city of Pompeii. Plaster is found throughout ancient Mideast architecture. The Babylonians lived in houses with plaster walls. The Abuhav Synagogue Tzfat in Israel features extensive plaster work. Plaster is even found in Japanese architecture. Why has drywall replaced plaster in most construction applications? How did this transition take place?
In the 19th century, plaster was used extensively in residential construction. By the early 20th century, plaster was still the industry standard and was used extensively in both residential and commercial construction. Most homes built in the eastern seaboard and midwest have plaster throughout. But that gradually changed in the 1940s and 1950s.
In 1903 the United States Gypsum Company (USG®) invented a product called Pryobar. Pryobar was sold as small tiles for fireproofing.
The Sacket Plaster Board company invented SacketBoard in the very early 1900s. SacketBoard was a panel made of several layers of plaster and paper. The U.S. Gypsum (USG®) company purchased the Sacket Plaster Board company in 1909. Just a few years later in 1916 USG invented a product they called Sheetrock®. Most builders however were slow to use the new material. Plaster had been around for millenniums. What would influence builders to make the change to drywall?
When drywall first started catching on in construction, it was often used together with plaster. Quarter inch thick sheets of drywall were used as replacements for wood lath. This early form of drywall was not made with smooth surface paper that was meant to be painted directly. That early drywall was used as a sub-surface only. It was installed over bare studs. Then, one or two thin layers of plaster were spread over the entire drywall sub-surface. In this way, the finished surface was still completely made of plaster.
As drywall technology improved, the quality of the surface paper improved. This made it possible to paint drywall directly without needing a skim coat of plaster. Today, only the joints where two sheets of drywall meet are taped and finished to create smooth walls.
Less labor means lower cost
To plaster a home, thin strips of wood, called lath, were nailed over bare studs. When installing wood lath, a quarter-inch to a half-inch gap was left between each strip of wood. A base coat of plaster was then spread over the lath to create a foundation. The base coat of plaster was pushed through the gaps between strips of lath to anchor it to the subsurface. As the base coat dried, it created what is called "keys" that hold the plaster in place. Finally, one or two finish coats of plaster were spread over top to smooth out any imperfections. The finished plaster was anywhere from 5/8 to 3/4 inches thick.
The labor involved in traditional plasterwork is considerable. However, with drywall, a journeyman hanger can cut large sheets of drywall to size, and nail or screw them into place. Rather than troweling the entire wall with two or three layers of plaster, a drywall finisher only needs to tape and float the seams, corners, and nails. The amount of labor required to do plasterwork can be four times as much as it takes to hang, tape, and finish drywall. As a result of the increased labor, plaster is much more expensive than drywall. This is the primary reason that more and more builders started using drywall in new construction.
Following WWII, several factors combined to create a real estate expansion that accelerated the use of drywall. Following the devastating effects of WWII which came on the heels of the Great Depression, many people desperately desired a return to the ideals of pursuing the American Dream. The Housing Act of 1949 facilitated the construction of thousands of homes across the United States. In addition, with the development of the Interstate Highway system, more and more people were moving to the suburbs. It was in this context that Drywall surpassed plaster in the industry. By the late 1950s and 1960s, though plaster was still found in new construction, drywall was beginning to be used at an increasing rate.
Drywall takes over as the industry standard
Drywall continues to improve. Today you can purchase sheets of drywall in almost any size needed. In addition to the variety in lengths and widths available there are different types of gypsum board for different applications. Fire retardant drywall panels are used in nearly every type of construction. There are drywall panels that can hold up in increased moisture conditions. There is drywall that resists mold growth. There is drywall that resists indentation for use in high-traffic or high-abuse areas. There is drywall specifically designed for elevator shaft applications where fire protection is of utmost importance.
Is Plaster Dead
Plaster work is still needed in certain applications. Though it is more and more difficult to find skilled tradesmen who can do plaster work, their talents are still in demand. Today, plaster is primarily used in commercial and industrial building construction where durability or moisture control is important. Stairwells in industrial buildings are common areas for plaster since they are often built using cinder blocks or poured concrete walls. A layer of plaster is spread directly over the concrete to create smooth walls. Areas of high moisture are other possible applications for plaster since it holds up better in these conditions.
The years ahead will certainly bring advances in technology and materials that will likely make their way into the realm of construction. Will a new product replace drywall as the industry standard for interior finishing? It is possible, and only time will tell.