A U.S. drywall manufacturer is on the defensive, following the filing of a lawsuit that claims its wallboard has caused corrosion and other problems in homes similar to what has been blamed on Chinese drywall.

Currently, more than 3,000 lawsuits over Chinese drywall are pending in a multidistrict litigation underway in federal court in Louisiana.

Last week, we reported that two Florida families had filed suit against National Gypsum over allegedly defective drywall. George and Brenda Brincku of Alva, and Lydia and Apolinar Garcia of Cape Coral, were listed as lead plaintiffs in the National Gypsum lawsuit. Both families claim that they experienced problems in their homes normally attributed to the presence of Chinese drywall.

The Consumer Products Safety Commission (CPSC) report on the Brincku home says 92 percent of the wallboard was made by National Gypsum and 8 percent was made by Chicago’s USG Corp. The complaint said tests conducted by the Massachusetts Institute for Technology (MIT) on drywall from the Brincku home supported the lawsuit’s claims.

The wallboard poured into the U.S. between 1999 and 2007 because of the high demand created by the housing boom. Imports accelerated when the rebuilding that followed Hurricane Charley in Florida in 2004, and Hurricane Katrina along the Gulf Coast in 2005, created a drywall shortage. According to an earlier Wall Street Journal report, some 500 million pounds of Chinese drywall was imported to the U.S. during the housing boom. That means as many as 100,000 homes throughout the country could have been built with the material.

National Gypsum says it did not, in fact, manufacture the drywall tested by MIT, and points out that a second brand of drywall was also used in the Brincku home. National Gypsum also claims a separate test conducted by Packer Engineering, an international firm hired by National Gypsum, found that the problems were not caused by National Gypsum or other domestically-produced wallboard in the Brincku home.