Prior to 1894, gypsum had been used for thousands of years as a building material and as an architectural detailing element. The first evidence of the use of gypsum in building construction appears to have occurred in 3700 B.C., when the Egyptians used gypsum blocks and plaster applied over woven straw lath in the building of the pyramid of Choeps. As a testimony to the strength and durability of gypsum, some of this construction, including walls decorated with murals composed of tinted plaster, is still intact and viewable. Further evidence of the historical use of gypsum includes its incorporation in the palace of King Minos of Crete in the period, around 1200 B.C. and the use of Alabaster, a form of gypsum, by sculptors during the Middle Ages.
In the late 1700s, the French chemist Lavoisier analyzed the chemical make-up of gypsum. His work and subsequent research by a group of his contemporary chemists, coupled with the discovery and mining of huge reserves of gypsum near Paris, led to the wholesale use of "Plaster of Paris" as a building material. Plaster of Paris-raw gypsum that is chemically altered by heat to remove much of the water contained in the gypsum molecule and then hydrated to make it useable as a plastering material-remains a viable product to this day.
Coming to AmericaDuring the same time, Benjamin Franklin brought to America the concept of using gypsum for agricultural purposes. During a trip to France, Franklin had observed French farmers using gypsum as a soil additive. He was so impressed by the concept that he began to enthusiastically promote it upon his return to America. Initial supplies of agricultural gypsum were imported to the states from Nova Scotia until 1792, when large gypsum beds were discovered in New York State. For roughly the next 100 years, the primary use of gypsum in the U.S. was as a soil additive and gypsum mines opened up in several locations, most notably near Ft. Dodge, Iowa, which eventually boasted the highest concentration of gypsum facilities in the U.S.
In 1880, Augustine Sackett and Fred Kane conceived the idea of producing wallboard and a machine to manufacture the product. Unfortunately, their initial efforts to produce a product from straw paper and tar were unsuccessful and they were able to produce only a highly combustible, unusable product. They persisted with their concept, however and in 1888 were able to produce Sackett Board using Plaster of Paris sandwiched between several layers of felt paper.
A sheet of Sackett Board was approximately 1/4 inch thick and 36 inches square. It had open edges, which tended to erode and the felt paper did not provide for a satisfactory wall finish. However, it was an excellent base for the application of gypsum plaster and it soon became a replacement for wooden slat lath in many geographic areas.
The acceptance of Sackett's product was helped by several concurrent advancements in gypsum plaster technology-most notably changes in formulation that improved both the workability and the working time of gypsum plaster. To demonstrate the potential of gypsum plaster, the Alabaster Co. used a mixture of gypsum plaster and fiber to finish the exterior of the 1893 Chicago World Columbian Exposition, thus filling the largest single order of gypsum plaster that had ever been completed to that date.
In 1894, Sackett had patented his manufacturing process for Sackett Board. He opened several production facilities over the next eight years and by 1901, he was producing nearly 5 million square feet of board annually.
Turn of the centurySensing the promise for the material, a group of small gypsum producers combined to form the United States Gypsum Co. By the end of 1902, the company had a total of 37 operations. In 1907, the Canadian Gypsum Co. was formed, providing access to gypsum deposits in Nova Scotia.
In 1909, Sackett sold the Sackett Plaster Board Co. (formerly the Sackett Wall Board Co.) to USG, where he served as a director until his death in 1914. In 1910, a process for wrapping the board edges was created. This was followed in short succession by the elimination of the two inner layers of felt paper, the replacement of the exterior felt facing with a paper-based covering, and the production of board in standard 4-foot widths. By 1916, Sackett Board had evolved into a ready-to-finish panel; within a year, the production of the original product was discontinued.
The demand for gypsum board accelerated during World War I. The first call-up of U.S. troops in 1917 created an urgent need for temporary military housing, both at home and overseas. The military used a variety of building materials to meet this need; however, a barracks fire that took the lives of several servicemen led military specifiers to look for naturally fire-resistant materials. Gypsum board met this need and consequently became the preferred building material for military housing construction.
In the '20s several companies joined the gypsum board industry, including CertainTeed Products Co. and the National Gypsum Co. Notable technological improvements during the decade included the invention of air-entrainment equipment to make board lighter and less brittle, and the evolution of joint treatment materials and systems.
In April 1930, the Gypsum Association was founded by 12 gypsum producers. During the first meeting, a constitution and bylaws were approved; an engineer and a traffic manager were appointed; and an agreement was reached to rent office space in Chicago. Early on, the association conducted several fire resistance tests that enabled all member companies to use the approved designs, provided that they certified that their products complied with the tested materials. However, many of the producers struggled during the Great Depression and association records reflect that all involved parties were "cutting costs wherever they could."
During the '40s, gypsum wall sheathing and gypsum roof sheathing products were used along with gypsum board in domestic and overseas military construction. By 1945, the military had used approximately 2.5 billion square feet of gypsum board. In 1946, gypsum products were used extensively to fuel a housing boom; by the end of the decade the industry launched a major public relations campaign that reached an estimated 54 million Americans. The period immediately after World War II also saw the first wholesale marketing of Type X gypsum board.
The '50s brought many innovations in gypsum board technology, including the listing of additional fire tests, the development of specialized nails for the attachment of board, the use of gypsum board in curved partitions, studless partitions, and sound control systems. Lightweight gypsum lath, plaster, and gypsum board systems fueled a boom period for the use of gypsum products in both residential and commercial construction industries. By 1955, an estimated 50 percent of new homes were built using gypsum wallboard; the other 50 percent with built with gypsum lath and plaster.
In the '60s the industry began to focus on expanding the use of gypsum board in non-residential construction, in particular concentrating on apartment building and office tower design solutions. To meet the specialized demands of high-rise construction, the decade saw the development of such concepts as gypsum board shaftwall systems and movable partition systems as well as "improved" Type X core gypsum products. During the late '60s through the early 1970s, the industry promoted these systems-along with membrane fireproofing and steel framing-by placing advertising in several industry publications and conducting training sessions with building officials and specifiers. These developments led to the extensive use of gypsum products in some of the world's tallest buildings; the industry proudly featured its use in the John Hancock Center (100 stories) and the Sears Building (110 stories, the tallest in its day), among others.
Of significance during the 1980s was the development and marketing of gypsum board firewall systems to separate individual town homes and condominiums. By adapting recently developed shaftwall systems to meet specific building code requirements, the industry was able to create an effective alternative to traditional masonry firewalls with no compromise in fire rating or sound attenuation. Today, only 25 years after introduced, the systems are widely used throughout the U.S. and Canada in residential construction.
During the same decade the vast possibilities of the potential for synthetic gypsum were first unlocked; and by the '90s, entire board production facilities were dedicated to using synthetic byproduct gypsum as the only source of gypsum for the manufacturing of board. The decade also saw the industry begin a trend toward the development of a variety of specialized board and panel products. Using the basic gypsum board theme as a template, industry research specialists have been able to create a vast range of proprietary materials to meet modern design and serviceability demands.
From a somewhat humble beginning as a basic building material, gypsum board has become the interior finish material of choice in the North American construction market. The ability of the basic gypsum mineral to adapt to a variety of circumstances has allowed it to be recast and reformulated over many centuries into a variety of different materials. Adaptive uses for gypsum are still being sought and its future as a building material remains bright.