USG Corporation

USG Corporation, also known as United States Gypsum Corporation, is an American company which manufactures construction materials, most notably drywall and joint compound. The company is the largest distributor of wallboard in the United States and the largest manufacturer of gypsum products in North America. It is also a major consumer of synthetic gypsum, a byproduct of flue-gas desulfurization.Its corporate offices are located at 550 West Adams Street in Chicago, Illinois.Together with other construction products, USG's most significant brands are:* SHEETROCK Brand gypsum wallboard* FIBEROCK Brand Panels* SECUROCK Brand Roof Board* SHEETROCK Brand TUFF-HIDE Primer-Surfacer In December 2013, Warren Buffett's Berkshire Hathaway became the largest shareholder in the company (holding roughly 30%) when it converted USG convertible notes it had acquired in 2008 to common stock.HistoryIn the 1890s, gypsum manufacturers perfected a method of strengthening plaster by adding a retarder, which controlled the setting time, thus creating a viable competitor to traditional lime plaster. Because gypsum was plentiful, and available at a relatively low price, and because the manufacturing process was so simple, new firms flooded and fragmented the market, placing constant downward pressure on prices.