As unsightly, and bad for allergic individuals, as mold infestation in the home can be, there are toxic molds out there that are finding their way into homes with increasing frequency.  Agents like Stachybotyris chartarum actually produce poisons that can attack the nervous and immune systems as well as the cognitive functions of humans.  As is the case for other molds, dampness and darkness are generally needed for their growth.  But the special way that homes have been built in the last fifteen or more years is a literal invitation to such infestation, which can destroy the value of a house for habitation.  This is now a very big legal and insurance coverage problem, as well as a disaster for persons so affected.

As I understand it, a newer house - from the outside in - consists of the following layers: siding, Tyvek material wrapping (which reportedly can "breathe"), plywood, studs, plastic sheeting (which cannot"breathe"), sheetrock (a paper product), and drywall.  Any moisture from within the house (or from without in case of a leak) collects between the plastic and the drywall, growing luxurously on the sheetrock.  Such sheetrock is typically found to be blackened by toxic and other mold growth.

Efforts are now under way to produce a type of sheetrock composed of fiberboard and resin instead of the mold-nutrient paper. Meanwhile, homeowners should be especially vigilant to catch such a problem at the earliest possible time.  There may not be a second chance.  In addition, people planning to build a new home, or to add to an existing home - and their builders - should discuss leaving out the plastic layer noted above.  Some builders alternatively breach the plastic in order to allow the house to "breathe".  Anyway, this is not a minor problem.

GS