I hope you checked out where the sheetrock came from before you bought it. Some of it from China is causing MAJOR health issues in homes where it was installed. In south Florida, where my In-laws have a home, there are houses that have been condemned that have the Chinese drywall. Many are now held by banks and have been selling for pennies on the dollar to folks who have to completely strip them clean and redo the insides. My in-laws have bought and flipped several of those.

Chinese-made drywall ruining homes, owners say - CNN.com