This is a good question: On its face, Chinese drywall looks exactly like US-made drywall. So, you need to look a little closer to notice its signs and effects. Here are some indicators that your drywall is Chinese drywall:
1. The sulfur contained in the Chinese drywalls is at such a high level that when mixed with moisture, it causes a corrosive gas that can eat away at objects in the home. To see if this damage is being done, look at the copper coils on your air conditioner. Damage to these coils is an indicator that the drywall may be of Chinese origin.
2. The smell from the corrosive gas emitted from Chinese drywall is very potent and smells similar to rotten eggs. This noticeable indicator may tell you that your drywall is from China.
3. From your attic, take a look at your drywall for the name KNAUF. The drywall may also say Knauf Plasterboard (Tianjin). These are definite indicators of Chinese drywall.
For more information on deciding whether your home has Chinese drywall, visit (http://www.nbc-2.com/Articles/readarticle.asp?articleid=24416&z=3).
Some Facts and Information about Chinese Drywall