UF launches study to understand defective drywall

Mar 13, 2009

South Florida Business-Journal–March 13, 2009

by Paul Brinkmann
Kathleen Cabble/Tampa Bay Business Journal

The University of Florida’s Rinker School of Building Construction is launching a preliminary study of problems caused by defective high-sulfur drywall in homes throughout Florida.

The study will look at sources of the mineral gypsum, the main ingredient in drywall, and how high-sulfur gypsum might create sulfur gases that smell of rotten eggs and corrode metal, said Adbol Chini, the school’s director.

More than 100 complaints of high-sulfur drywall are being tracked by the Florida Department of Health in a growing product liability crisis. More than a dozen complaints come from South Florida’s three counties. The U.S. Consumer Product Safety Commission is also investigating the problem.

“I’m going to ask our graduate students to look into this, as a first step,” Chini said. “There’s been very little talk about the cause of this problem, and that’s what intrigues me. If there are problems with a certain building material, and we don’t know the cause, that’s why the school is here.”

After some initial study, Chini said the school may seek grants to study the problem further.

A Chinese manufacturer, Knauf Plasterboard Tianjin, has acknowledged some of its drywall imported to the U.S. in 2006 is associated with complaints of odors. But, the company has said the problem is tied to gypsum from a natural gypsum mine in Tianjin, China – and that mine is no longer used.

Chini said concerns about sulfur out-gassing from drywall are not new. He noted that disposal of drywall in some Canadian landfills is forbidden because of concerns about buildup of corrosive sulfur gases.

Imported Chinese drywall was used in some South Florida homes during 2005 and 2006, including homes built by Lennar Corp., which launched a program to remove drywall from problem houses.
Domestic plant in apollo beach

But, many builders have traditionally relied on domestic manufacturers. The closest plant is National Gypsum Co.’s Apollo Beach facility near Tampa, which uses synthetic and natural source gypsum. The company’s synthetic gypsum comes from Tampa Electric Co.

Since the National Gypsum plant opened in 2001, more than 9 billion square feet of drywall have been produced, and no problems were reported with its product, said Patrick Macary, the plant’s quality manager.

“If there was something wrong with our process, we would’ve heard something by now,” he said. “Our company does not import anything, and our company does not rebrand anything as our own.”

The national Gypsum Association, based in Hyattsville, Md., says about 20 percent to 30 percent of U.S. drywall is made with synthetic gypsum produced in pollution scrubbers at coal-fired power plants. Synthetic gypsum is produced when limestone scrubbers remove sulfur gases from smokestack emissions. Synthetic gypsum is chemically identical to naturally mined gypsum.

Chini said the school likely would examine both natural gypsum and synthetic gypsum.

Michael Gardner, executive director of the Gypsum Association, said the group has not seen a need to investigate sources.

“At this juncture, all the problems have been attributed to Chinese material, so we have taken a wait-and-see attitude,” he said. “There was an interesting supply and demand scenario in 2006. There was an extreme demand for board, and this Chinese material was attempting to fill that void.”

Gardner said the association issued statements advising people to be wary of any previously unknown sources.

Homeowners have filed several class action lawsuits against builders or manufacturers. One law firm, Colson Hicks Eidson in Miami, said it was representing a homeowner with a complaint against a domestic drywall manufacturer, but no other examples have come to light.