There are many types of mold – all of them need water or moisture to grow. When excessive moisture accumulates and remains undiscovered or unaddressed the formation occurs quickly

Molds spread by producing tiny reproductive cells called spores that waft through the air. Some molds have spores that are easily disturbed and settle repeatedly with each disturbance. Other molds have sticky spores that will cling to surfaces and are dislodged by brushing against them or by other direct contact

Spores may remain able to grow for years after they are produced. In addition, whether or not the spores are alive, the allergens in and on them may remain allergenic for years