What is Defective Drywall? 

Defective Drywall (sometimes called Chinese Drywall) refers to defective or tainted drywall imported from China from 2001 to 2007 which emits sulfur gasses which usually (but not always) creates a noxious odor and corrodes copper and other metal surfaces, thereby damaging your air conditioner, electrical wiring, copper plumbing, appliances and electronics.  Defective drywall can also cause adverse health effects, although experts disagree whether these effects are merely irritants or present a more imminent or chronic health hazard. But please understand that not all drywall manufactured in China is defective.

Is Defective Drywall Dangerous? 

There is no question that the gasses emitted from Defective drywall corrode copper and metal surfaces. Corrosion of electrical wiring may hamper the effectiveness of smoke detectors, which clearly presents a safety concern. Low level arcing has also been observed in some homes with Defective drywall, which could cause an electrical fire.

Could Defective Drywall be in my Home or Business?

Hundreds of millions of sheets of Defective drywall were imported from 2004 to 2006, but Defective drywall has recently been found in homes built or remodeled as early as 2001. Accordingly, this phenomenon cannot be explained solely by the shortage of American-manufactured drywall. The presence of Defective drywall has been reported in 37 states, the District of Columbia and Puerto Rico is estimated to have been installed in over 100,000 homes in the United States. Unfortunately, this does not paint an accurate picture as most affected homes have a mixture of safe and tainted drywall.

Defective drywall is 1/2" in width, although Lori A. Streit, Ph.D., from Unified Engineering, states the same compounds found in problematic Chinese drywall and the same gases released there from have also been found in drywall measuring 5/8" (which is typically used in ceilings). Defective drywall is typically mixed in with untainted drywall, which is why people should not assume that their home is fine if they find U.S. drywall. Moreover, U.S. drywall may have been manufactured in China and re-branded.

What are the signs of Defective Drywall?

Does your home smell like rotten eggs or ammonia (sometimes a sweetish smell)? Is it more noticeable when entering your home and then seems to dissipate? The level of odor varies greatly in each home as does each person’s ability to detect the odor. Of course, the strength of the odor also depends on how much drywall was used in the home. Significantly, some homeowners report no smell, but their home clearly has Defective drywall. In short, do not rely on your nose alone, particularly since many develop olfactory fatigue after being exposed to Defective drywall.

One of the telltale signs is corrosion/pitting of the air conditioner evaporator coils (which are located inside the air handler).  Many owners are first advised of a Freon leak, and as the corrosion progresses, evaporator coils eventually need replacement. An examination of the coils typically (but not always) reveal a black sooty deposit, which may also appear on the Freon line. 
Defective drywall also corrodes electrical wiring. After turning off the power (please be careful as you could get shocked), check the electrical receptacles in your walls to see if the ground wires are blackened. Since many homes have mixed drywall (i.e., good and bad drywall), not all ground wires will show blackening. There are also cases that are not clear cut so please consult a qualified inspector.

Signs of an electrical problem include a circuit breaker which frequently needs resetting without an apparent cause (particularly a GFCI or AFCI); lights that flicker without any apparent cause; bright flashes or sparks anywhere in your electrical system (this may indicate arcing conditions in the wiring); buzzing from electrical systems, switch plates, dimmers and outlet covers that are discolored from overheating; and a smell from overheating plastic.

How do you test for Defective Drywall?

Inspecting for Defective drywall can be very difficult. At A1 Certified Home Inspections, we offer two stages to our Defective Drywall Inspections.

Stage #1 - The visual inspection. Here we check for all of the Tell-Tale clues that Defective Drywall may exist. We will inspect the electrical wiring in the home for blackening. From the main Load Center to the outlets and switches in the rooms. We will inspect the A/C coils for evidence of soot or blackening. We will inspect the plumbing pipes and fixtures for blackening. We will go into the attic and check the reverse side of the drywall ceilings for the "Made In China" labels (However, this is not always foolproof because ceilings are typically made from 5/8" drywall, and most tainted drywall is 1/2"). We will try to determine if the home has a foul smell, like rotten eggs, as most home owners cannot smell the odor after being exposed to it while living in the home.

Stage #2 - Laboratory Testing. Laboratory tests may be used to confirm the findings in our visual home inspection, and to demonstrate that corrosion effects are due to drywall, and not other items in the home (e.g. carpets, cleaners, paints, personal care products). This is particularly important if you are planning legal action. A very common and accurate test is the GC/ECD Test.

The GC/ECD test is a robust, low-cost analysis that allows us to screen a large number of drywall samples. Because drywall used in home construction can be from mixed sources, submission of multiple samples from your home may be done to reduce the risk of false negative results. Roughly 5g (approximately 2”x2”) of bulk drywall material is all that is required for the GC/ECD analysis. Results are reported in units of mg/kg. A positive result above 10 mg/kg is indicative of corrosive drywall, according to the FL DOH's Case Definition (12-18-09) for Drywall Associated Corrosion in Residences.