In 2004, hurricane damage and flooding in the southeastern United States coupled with a nationwide home building boom created a strong demand for gypsum wallboard, which outstripped domestic supplies. Drywall was imported from China beginning as early as 1999, with an increase in quantities between 2004 and 2007. Approximately 550 million pounds or seven million sheets of drywall were imported, which was enough for 40,000 homes. Approximately 60 percent was delivered to Florida, predominantly for new home construction and 11 percent to Louisiana, for storm-related water damage. The rest was scattered across 35 other states, including the District of Columbia and Puerto Rico. In the years since its arrival in the United States, some of the drywall imported from China has caused corrosion of mechanical and electrical systems along with an unpleasant odor.The preferred descriptive term for this building material is corrosive drywall frequently abbreviated as CDW.

Read the full article by Allan Burt, published in Cleaning & Restoration, June 2010.