Drywall is stuff you see every day. It’s in your home, your school, your office and in every store you visit. Drywall is a construction material that makes up walls and ceilings, as well as other design features like arches, eaves, and other architectural features. It provides smooth surfaces for walls and ceilings, and can also add fire and sound resistance. It is also used to wrap columns to hide steel beams and top off masonry walls above ceilings.
Some people are confused as to how drywall and sheetrock vary from one another. To clear the confusion, ‘sheetrock’ is a brand name of drywall, as to ‘Kleenex’ is to tissues. The ‘Sheetrock’ brand is owned by the United States Gypsum Company, commonly known as USG. They own an entire line of products under the Sheetrock brand, such as gypsum panels, joint tape, and joint compound. But interestingly, the name has been used for so long that some people refer to ‘gypsum panels’ as ‘sheetrock,’ no matter what company really manufactured the material.
Besides Sheetrock, drywall is also known as plasterboard, wallboard, gypsum panel, gypsum board, or just plain ‘rock.’ It is a panel made of gypsum, or calcium sulfate dihydrate, that is with or without additives, and is usually pressed between a facer and a backer – normally thick sheets of paper.
Before drywall became widely used, building interiors were made of plaster. It has been around for millenniums. Ancient Egyptians burnt gypsums in open air fires to produce plaster. Their first use of gypsum in construction appears to have happened in 3,700 B.C. when the Egyptians used plaster and gypsum blocks over woven straw lath in building the pyramid of Cheops.
In Ancient Greece, the palace of King Minos was built with alabaster, a form of gypsum used by sculptors in the Middle Ages. It was built around 1,200 B.C. The Babylonians and Romans also used plaster for architecture and decorative structures.
In the 1700s, French chemist Antoine Lavoisier analyzed the chemical composition of gypsum. His work is one of the advancements that led to the wholesale use of “Plaster of Paris” as a building material. Plaster of Paris is made up of raw gypsum that is chemically altered by heat and is still a viable product until today.
Drywall in America
In the US, Augustine Sackett and Fred Kane came up with the idea of creating wallboard made of straw, tar, and paper. They designed a machine to manufacture it in the 1880s. In 1888, they developed the Sackett Board using Plaster of Paris sandwiched between layers of felt paper. The Sackett board was patented in 1894 by Sackett, who was considered to be the grandfather of the gypsum board manufacturing industry. The modern gypsum board has evolved from the Sackett board.
The gypsum board continued to evolve. In 1910, the process for wrapping the edges of the board was created, and the two inner layers of felt paper were also eliminated to replace it with paper-based covering. That same year, the United States Gypsum Corporation bought Sackett Plaster Board Company. By 1917, they replaced the Sacket Board with the drywall product they called Sheetrock.
During World War I in 1917, the call-up of US troops created an urgent need for temporary military housing, both in the country and overseas. Different types of building materials were used to meet this need, but when the military experienced a barracks fire that took the lives of several servicemen, they sought for naturally fire-resistant building material. Gypsum board became a solution and since then, it was the preferred material for building military housing.
Sheetrock was commercially sold as the poor man’s answer to plaster walls. In 1921, USG’s advertisement for sheetrock marketed it as a fireproof wall, in which “no time is lost in preparing materials, changing types of labor or waiting for the building to dry.”
Drywall didn’t enjoy widespread use immediately. Most builders were hesitant to use the then-new material since they thought it was just a substandard alternative for the tried and tested method of spreading layers of plaster over lath to create a very hard, durable and smooth wall.
It wasn’t until World War II broke out when more and more builders used drywall. As the country’s labor force became focused on manufacturing for war, cheaper materials were needed to offset the labor storage and war costs. Plastering became an expensive building option due to a shortage of labor, so people began to use drywall instead. Domestic, commercial and military field preferred drywall, which made construction much quicker and with less labor previously needed. People then consider spending less time and money as being patriotic since they can allow other resources in supporting the war efforts.
When the war ended, drywall gradually became the dominant building material in the country. By 1955, around 50% of new homes were built using gypsum wall, while the other 50% were still built with plaster and gypsum lath. The baby boom in 1946 to 1960 caused sales to grow rapidly, as more than 21 million new houses were built nationwide. More builders decided to abandon plaster for drywall since they can construct buildings for just one-tenth of the original time they were spending back then when they were using plaster.
During the 1950s, the drywall technology continually improved. It was tested in more fire tests to improve fire resistance. Manufacturers also developed specialized fasteners for the attachment of board, as well as the use of gypsum board in different types of room partitions and sound control systems.
In the 1960s and 1970s, the use of gypsum board expanded in commercial construction particularly in office towers and apartment buildings. To meet the special demands for high-rise construction, the industry manufacturers developed innovations like the movable partition systems, gypsum board shaftwall systems and the improved type X core gypsum products, which had higher fire resistance ratings.
Over time, the use of plaster gradually faded all over the world as they turned to drywall. In 2007, USG had net sales of more than $5 billion and is still one of the world’s top producer of drywall and other gypsum-related products. In North America, USG is the largest gypsum manufacturer. It gets its gypsum from mines, while some are from a synthetically engineered by-product of coal-fired power plants.