Synthetic drywall rots mechanical product

The Consumer Product Safety Commission has confirmed what many people have suspected for quite a while now — Chinese-made drywall is causing corrosion of plumbing, mechanical and electrical products in homes where it was installed. At the same time, however, scientists and engineers at CPSC and the National Institute of Standards and Technology point out that they don't yet know how much long-term damage is caused by the corrosive compounds released by the drywall. Anything in the homes that is made out of copper and silver is turning black on the outside, but NIST is still investigating the point at which the corrosion leads to failure.

Drywall is basically paper-covered calcium sulfate, so it will always contain a certain amount of sulfur. Synthetic drywall, which seems to be the culprit here, is often made from byproducts of flue gas desulfurization in coal-fired power plants.

The April 30, 2009, edition of Ecohome magazine ran a story about a Florida homebuilder who bought domestic synthetic drywall from 84 Lumber made by Georgia Pacific for his own house. The builder is suing both for damages, claiming, “The plumbing fixtures and several silver picture frames in the plaintiffs' home started to corrode, the suit maintains. In January 2008, coils in the house's HVAC unit developed a leak. The coils were replaced, but in July 2008 they sprung another leak … The smoke detectors in the plaintiffs' home randomly go off without cause, and the home has a strong sulfur odor throughout, the suit reads. All the copper ground wires attached to every light-switch and outlet in the home have turned black and are rapidly oxidizing.” You can read the whole story at http://www.ecohomemagazine.com/news/2009/april/florida-lawsuit-claims-gp-84-sold-dangerous-drywall.aspx.

CPSC and NIST are in the midst of testing a variety of mechanical products, including HVAC equipment and fire sprinklers. The Feds worry that sprinklers, especially those with metallic fusible links, may either go off accidently or fail to open in a fire.

CPSC released results of a 51-home study conducted by Environmental Health & Engineering (EH&E), an internationally known environmental testing firm based in Massachusetts. EH&E compared 41 “complaint” homes in five states selected from CPSC's consumer incident report database, with 10 non-complaint homes built around the same time in the same area as the complaint homes. Homes were sampled between July and September 2009.

The EH&E findings are that hydrogen sulfide gas is the essential component that causes copper and silver sulfide corrosion found in the complaint homes. Other factors, including air exchange rates, formaldehyde and other air contaminants contribute to the reported problems.

EH&E exposed copper and silver test strips, known as coupons, in homes for a period of about two weeks. The coupons showed significantly higher rates of corrosion in complaint homes than in the control homes. The dominant type of corrosion on the coupons was copper sulfide and silver sulfide.

While that corrosion may be ugly, the NIST Material Science and Engineering Laboratory is trying to determine if and when the corrosion is going to create leaks, a potentially deadly problem if it involves copper gas pipe. So far, none of the material that's been removed from test homes has shown signs of leakage.

The big question is, who's going to pay for all this? Who's going to pay to gut-rehab 30,000 to 40,000 homes? Our friend Steve Irwin, Farmer & Irwin, Riviera Beach, Fla., told us a number of months back that he had heard of some Florida homebuilders who were repairing the damage on their own and making claims against their insurance carriers. Call me cynical, but I don't think the insurance companies are going to be quick to write checks anymore. Lawyers, in particular, will get rich. Some suppliers may be sunk as this turns into their version of asbestos. We're beginning to hear some call for another government bailout.

We believe that the drywall suppliers and their insurance companies should take the hit for this. Asbestos spelled the end for Johns-Manville and W.R. Grace. Synthetic drywall may be the coup de grâce for some here. Then plumbing-heating-cooling and electrical contractors can get back to work restoring those homes.