As if there weren’t enough things to worry about in your home. Now it appears that imported drywall is causing foul odors, damaging copper components, and making people sick. So is this a case of mistaken identity or a true concern?
During the 2004 – 2005 building boom, home builders had trouble obtaining enough drywall for all of the houses they were building. They searched for other sources and sure enough, they found suppliers in China. The price and quantity were right, so it was installed in many homes. But the problems started showing up over the last year or so. Air conditioning units started to fail, plumbing was corroding, and people complained about foul sulfur odors.
When the AC coils were opened the copper tubing inside was black. According to Trane, a manufacturer of AC equipment, the coils looked like they were 20 years old, not two or three. Upon further investigation, the same black scale was found on the copper plumbing and electrical wiring. All of these findings were coupled with that same sulfur smell.
Tests are still underway, but it is assumed that the Chinese drywall contains ash from the many coal-fired power plants in China. China has low quality coal that has high sulfur content. The ash from the plants may have been mixed with the gypsum used to make drywall. The sulfur leaks into the air as a gas and combines with the moisture on air conditioning coils to create sulfuric acid, which appears to be dissolving solder joints and copper tubing — creating leaks, blackening the coils and even causing the system to fail.
This issue appears to be limited to the Southeastern part of the United States and in particular Florida and Georgia. The high humidity may be contributing to the problem. The humidity is absorbed by the drywall which releases the sulfur gas. The humidity also causes condensation to form on pipes and AC coils, and when the gas is mixed with water if can create sulfuric acid. The odor is not immediately apparent until the drywall becomes damp, so the problem went un-noticed until after it was installed.
So how can you tell if you have Chinese drywall installed in your house? You need to look at the back of the drywall. This can be done by going into your attic and moving some insulation. You will see a stamp on the back of the drywall. Look for the manufacture code KNAUF. If you have it, contact your builder. The issue has yet to be resolved, but as you might guess, lawyers are lining up in droves.
If you are buying a house please note that your home inspector will not report on the type of drywall installed in your home. It is beyond the scope of a standard home inspection.