Corrosive, or so-called “Chinese” drywall, was imported into the country during a building boom and domestic shortage in 2004 – 2007. This was especially true in FL after Hurricane Katrina. High pyrite content caused the product to outgas sulfur compounds. This induced an accelerated blackening, corrosion, and failure on copper HVAC coils and wiring, and was a health hazard. Most corrosive drywall has been removed by now. Identification is by the copper deterioration, a pronounced sulfur smell in the home, and (sometimes) brand markings of “China” or “Knauf Tianjin” on the back side.
There is evidence of corrosive drywall present. Such “Chinese drywall” can cause corrosion on copper fittings or produce a smell similar to sulfur or rotten eggs. This is a health hazard. Hire an environmental specialist to evaluate the drywall and to make required repairs.
