Mold Inspections: A Common Sense Approach

Mold is present at low levels even in a very clean home. A mold-free home is unrealistic. Mold will not die and stays dormant unless the right conditions are met. Mold requires moisture, a food source such as wood, dust or paper and a temperature between 40°F-140°F to grow. When mold grows it produces spores that float through the air. Some mold is harmless, other molds cause allergic reactions in some people, similar to peanut butter or shell fish. Toxic mold is dangerous for everyone. Black mold, especially "stachybotrys", is highly toxic and should be removed. Don’t assume all black mold is toxic.

There are mold testing sample containers that can be set out in the living area of a house for a certain length of time and then sent away for a lab analysis. The results usually come back inconclusive.

All houses will provide the right temperature, and a food source for mold to grow. The only other condition required is moisture. Before you spend money for someone to come in your house to look for mold, there are some common sense inspections you can do first. Use your nose to trace the mold smells. Look for water leaks under sinks, toilets and tubs. Look for water damage on ceilings as well as basement seepage. High efficiency furnaces, humidifiers and air conditioners can leak water. Pull out the refrigerator to see if the condensate tray requires cleaning.

Basements and unheated rooms will cause condensation to form on the cool walls (like a glass of ice water in summer) and mold will follow. Make sure your house is not too humid by using exhaust fans when showering and cooking. Dishwashers, watering house plants, damaged dryer vents, open aquariums (among other things) all add humidity to the inside of the house. If your house was built after 1990 it is probably sealed well and will require constant ventilation. If your windows are wet in the winter, there is too much humidity in the house.

As you can see, there are many things that will cause excess moisture. It's more a matter of looking for those problematic issues than anything else. Most basements require a dehumidifier or an HRV to lower the relative humidity and prevent mold growth. The Canada Mortgage and Housing Corporation (CMHC) has a great website that will provide more information on controlling and cleaning mold.