I purchased a HUD foreclosed as an investment property. At one point, the house had freeze damage to the boiler heating system. The home was winterized for a couple of months before I bought it. My plumbing contractor cut a hole in the drywall ceiling to find where a had pipe split. The drywall underneath was black. We were unable to determine if it was black mold or dried soot from the water within the boiler. Whatever it was, it didn't penetrate through the paper of the drywall and the moisture that was there had long since dried. My drywall contractor almost immediately patched the hole. If it is black mold and the area is sealed and bone dry, will I have an issue later? My reading of mold is that if it doesn't have a moisture source, it dies quickly.

 

Mold requires 2 things - heat and moisture. IMO if that is the only evidence, I wouldn't be too concerned.