Mold colonizes buildings when a spore finds the coincidence ofmoisture, nutrient and shelter. Susan Doll1 conducted a seriesof experiments at the Harvard School of Public Health demonstrating,among other things, that building materials from the retail supplierarrive already inoculated with mold spores. Other portions of theresearch support the idea that mold growth can be expected in shelteredlocations where materials containing carbon (especially sugarsand starches) are exposed to liquid water for several days or relativehumidity levels of 95% for several weeks.