How to identify black mold

Black mould is a dangerous toxin that can infiltrate a home and cause illness and discomfort in unsuspecting occupants. Once black mould makes its way into the walls and other damp surfaces of a home, it can continue to spread if the problem is not corrected promptly. Varying types of mould spores are commonly found in the household environment, none of which carry health risks as serious as that of black mould. If you suspect black mould may be an issue in your home, prompt identification and cleanup is suggested.

Search water-damaged areas for signs of black mould. Basements, crawl spaces, laundry rooms and other areas of the home that have either had a water leak or maintain a high amount of moisture are prime sites for black mould growth.

Look for dark black patches of mould on walls and moulding. Areas that harbour damp flooring may contain mould on mouldings where the floor meets the walls. As the black mould spreads, it may begin to creep its way farther up the wall, further infiltrating the drywall and areas underneath.

Examine the black mould to see whether or not it is growing in a circular pattern. Black mould grows in a definitive pattern and does not deviate unless it spreads to an area that lacks moisture. The circular patterns of black mould appear slimy on wet wall surfaces and dry and sooty on areas that were previously moist and have since dried.

Check members of your family for skin irritations, sinus problems, congestion and fatigue. These can all be signs that a black mould problem is festering in your home. If a friend or loved one does not seem to be recovering from a suspected cold or allergy, black mould may be to blame.

Contact a licensed home inspector, who can determine whether or not you have a black mould issue in your home. A trained professional can definitively diagnose a black mould problem by doing a complete examination of the home. The inspector will also search inner walls, floorboards, carpeting and ceiling tiles.


Test kits are available that can help you detect the presence of black mould in your home. If a test result comes back positive, seek the help of a licensed inspector in deciding how to combat the problem. Removing the source of the moisture should be the first course of action when dealing with a black mould problem. If there is no dampness, mould cannot thrive. A black mould problem that is confined to a small area can be treated with bleach. It should be sufficient to scrub the area with a heavy-duty cleaner that contains bleach, then wipe the area dry. Removing carpeting that has been affected by water damage can prevent the growth of black mould. Follow this up by mopping the floor with bleach and water, allowing it to dry thoroughly, and replace the carpeting if desired.


If members of your household are showing signs of chronic illnesses that are affecting their respiratory system, it is advisable to check for black mould in your home. If it is found and eliminated, symptoms will usually subside.

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About the Author

Jonae Fredericks started writing in 2007. She also has a background as a licensed cosmetologist and certified skin-care specialist. Jonae Fredericks is a certified paraeducator, presently working in the public education system.