Mold cannot be identified by sight and there are thousands of species of mold. My job is the first step, which is to collect samples and have them analyzed by a laboratory, then the lab can let know if there is any cause for concern.
Mold is everywhere and is not uncommon to find in a home. It can enter the house through open doorways, windows, heating, ventilation, and air conditioning systems. Spores in the air outside attach themselves to people and animals, bringing mold indoors. Once the spores are inside, if they land on places where there is excessive moisture, they can grow.
Mold will grow in places where any leakage may have occurred, such as roofs, pipes, walls, plants pots, or where there has been flood damage. Many building materials can encourage mold growth once they get wet. Wet cellulose materials, like paper and paper products, cardboard, ceiling tiles, wood and wood products are all conducive to mold growth. Many building materials can support mold growth once water is introduced.
Some mold problems are obvious you will see it growing. You can also look for areas that are consistently wet, or have been wet due to flooding, leaky plumbing, or roofing and areas of high humidity (bathrooms, laundry rooms, kitchens).
Other mold problems are not so obvious. If you do not have any visible mold, but your home has a damp, musty smell or visible water stains, mold could be growing in areas you cannot see, such as in wall cavities or the ductwork of a heating/cooling system.
Look for visible signs of mold growth and signs of excessive moisture or water damage (water teaks, standing water, water stains, and condensation problems). The earlier the problem is detected, the better; mold activity can begin as soon as 24 hours after a moisture event.
•Search areas with noticeable moldy or musty odors.
•Search behind and underneath materials (carpet and pad, wallpaper, vinyl flooring, sink cabinets), furniture, pictures, or stored items (especially things placed near outside walls or on cold floors).
•Check around air-handling units for stagnant water. Keep these units serviced with regular cleaning of ducts and air filters.
•How is mold measured? How do you test for mold?
•Air sampling. Air samples are taken when any "red flag" conditions have been observed. Air sampling always includes inside and outside samples. If mold amounts inside the house are higher than outside, it is an indication of a potential problem. Air samples are taken by pulling air through a collection device with an air pump. The air passes over a slide, which catches the mold spores to be counted and identified.
•Swab sampling. Where there is visible mold or stains, a swab is used to collect a sample of the mold. It is moistened with a preservative and sent to a lab for analysis.
•Carpet sampling. A carpet tends to contain a history of what has been in the air. Unless the carpet has recently been cleaned, it may contain evidence of a mold problem. This type of test is not as common, but is done when necessary to discover previous or undetected mold problems that may have been covered over or cleaned up.