Chinese Drywall: How to Determine If You Have This Inferior Product

Corrosive effects of Chinese drywall on evaporator coils.

Chinesedrywall / Wikimedia Commons / CC BY 3.0

Not long ago, Chinese drywall seemed to be a minor problem. Now, not only is this problem expanding to include more homes, but the severity of the problem is increasing.

What It Is and Why It's a Problem

Some drywall coming from plants in China has been found to include phosphogypsum, a radioactive phosphorus substance.

Phosphogypsum contains radium. Exposure to radium, over time, can increase your risk for lung cancer. The EPA banned the use of phosphogypsum for U.S. firms in 1989. Its usage is not banned in China. In addition, this substance is corrosive, which can lead to structural failure.

How to Determine If You Have It

Here are some ways to narrow down the question of whether you have Chinese drywall containing phosphogypsum in your home. Do you fit any of these conditions:

  • Foul, sulfurous odors coming from your walls.
  • Metal in contact with relatively new drywall is corroding quickly.
  • Copper, in particular, will corrode rapidly in contact with bad drywall from China. Green corrosion is normal; black corrosion is not.
  • Black corrosion on wiring.
  • Appliances and electronics inexplicably failing (they have copper wiring, which can corrode).
  • Drywall is newer than 2001.
  • Look for markings on the backside of walls (i.e., in laundry rooms, basements, or other places where you might find unfinished drywall). Obviously, Chinese characters would indicate Chinese origin. Also the word "Knauf" will indicate this.

What to Do When You Have It

Unfortunately, the only solution is to remove all Chinese drywall from your home and replace with good drywall.


Remember that drywall is friable, so it could be risky for you to remove the material yourself. Unlike air-borne hazardous materials like lead-based paint and asbestos, phosphogypsum-based drywall cannot be "sealed" with a coat of paint.

So, removal and replacement is not the real question; that is a given. The real question is who will pay for the work. Many homeowners are joining class-action lawsuits.