Taking a Look at Issues With Drywall from China by Michael D. Conley
ASHI Certified Inspector
Published March 2009 Issues with drywall and drywall mud from China have been around since the late 1990s. More recently, drywall from China is being linked to health and safety issues, with the critical focus on drywall imported and used during the time period from 2004 to 2006. This time period coincides with the height of the Florida construction boom, in tandem with a shortage of drywall manufactured in this country.
The jury still is out on whether or not Chinese drywall creates a health issue. It seems to some it does to the degree that they have to move out of their homes. To others, it’s an expensive nuisance that is affecting components in their homes.
While some involved in this fray claim the defective drywall does not pose health or safety problems, many homeowners are complaining about health problems that seem to occur only when they are in their homes. Preliminary investigation by the Florida Department of Health concluded that current emission levels from drywall testing pose “no immediate health threat.”
Nevertheless, homeowners who are exposed to the problem say otherwise. Health concerns and health problems reported include an array of respiratory problems, nosebleeds, irritated eyes and headaches. Of concern is the possibility that the Chinese drywall is emitting excessive amounts of hydrogen sulfide fumes and ammonia gas, which can cause extreme irritation, unconsciousness and even death.
One inspector I spoke with said the drywall smelled like spent firecrackers. What do firecrackers have within their mix? Sulphur and ammonia.
Knauf, a German company manufacturing in China, produced some of the Chinese drywall in question. Knauf Plasterboard, Tianjin Co. Ltd. of China maintains that its Chinese drywall is safe and homeowner problems must be from some other source. But I spoke with a local consulting firm that stated the Knauf plasterboard is, in fact, defective. Also stated was that the ASTM standard (ASTM C36) used for the product was out of date and no longer recognized.
The American Society for Testing and Materials (ASTM) explained that the C36 standard was replaced more than four years ago with “ASTM C1396.” The C36 drywall was produced in March 2006, two years after that standard was changed.
Standard 1/2″ and 5/8″ fire-rated sheets are the culprits and they are not properly rated for fire resistance. My market area appears to be at the epicenter of the drywall-from-China quandary. Port Manatee is where millions of board-feet of this drywall was delivered and distributed throughout Florida and other parts of the southeast.
One homeowner reported that her jewelry was tarnishing quickly. Another homeowner complained that his A/C coil was corroding after only a year or two. Other indicators of a problem include black copper wiring in the main service panel and doorstops that turn black or look tarnished. Television sets, computers, microwaves and refrigerators all have been mentioned as susceptible.
Until we learn more, home inspectors can look for the following:
Drywall installed from 2004-2006. This appears to be the time period during which most of the drywall in questions was installed, but inspectors should allow leeway on both sides of those dates.
To identify the drywall, find a place where the backside is exposed (e.g., in the garage or attic where there is no insulation). –
Look for the words “CHINA” in red ink or “KNAUF” in black ink. – Look for C36 stamped on the back or edge tape, if available.
Use your nose or listen to any complaints from the homeowner. Sample a number of electrical receptacles and look at the copper wiring as well as the A/C coil.
Currently, there are about 80 complaints pertaining to this drywall, and it appears there will be more in the future. Lawsuits are pending with homebuilders and the manufacturer. As to the final outcome, who knows? All we can do is wait and see.