Jay- here's some helpful tips when inspecting for Chinese drywall-

Most of the affected homes were built during the housing boom between 2004 and 2007, especially in the wake of Hurricane Katrina when domestic building materials were in short supply.

Exposure to high levels of airborne hydrogen sulfide and other sulfur compounds from contaminated drywall can result in the following physical ailments:
• sore throat;
• sinus irritation;
• coughing;
• wheezing;
• headache;
• dry or burning eyes; and/or
• respiratory infections.
Ask the right questions and you may be able to get this info out of the seller.

An inspector can use the following tips to identify if a home’s drywall is contaminated:
• The house has a strong sulfur smell reminiscent of rotten eggs.
• Exposed copper wiring appears dark and corroded. Copper coils in refrigerators, air conditioners, and microwaves that are damaged in this fashion can fail. Silver jewelry and silverware can become similarly corroded and discolored after several months of exposure.
• A manufacturer’s label on the back of the drywall can be used to link it with manufacturers that are known to have used contaminated materials. One way to look for this is to enter the attic and remove some of the insulation. It can be difficult to find a label.
• Air sampling for the signs of the sulfur compounds emitted by Chinese drywall are available, but the laboratory cost to analyze routinely exceeds $1500 per sample!
• Drywall samples can be sent to a lab to be tested for dangerous levels of sulfur. This is the best testing method but also the most expensive.
• Drywall installed from 2004-2007. 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” or in red ink or “KNAUF” in black ink. Anything that says "MADE IN CHINA" should be suspect.
- 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.

Some large manufacturers named in these lawsuits are Knauf Plasterboard Tianjin, Knauf Gips, and Taishan Gypsum. Homes built by Lennar should be checked closely; they used Chinese drywall in 80 Florida homes. Best guess is that as many as 36,000 homes in Florida may have Chinese drywall. Most of the Florida homes affected have been in the Sarasota area, with a second concentration around Palm Beach; it has been found as far north as St. Augustine.