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The Dangers of Mold After a Flood (and How to Handle Them)

Mold can present a serious health issue and it can also eat away at building materials, insulation and support structures. Unfortunately, homes and the materials inside them can provide the right food source and the right conditions for mold to grow. It’s important to know what to do if you detect mold in your home.

Mold needs an organic food source to grow—like drywall, wood, paper, carpet, grout, wallpaper and fabrics—the kinds of materials you find in most homes. It also needs moisture and warmer temperatures.

Areas in the home where mold tends to grow include the basement, bathrooms, walls, ceiling corners, the attic, crawlspaces and on windowsills. If you live somewhere humid, the garage can also be place for mold to thrive. When you do your seasonal maintenance make sure to check these areas for mold.

There are thousands of different types of mold. It can be green, black, yellow, white, even pink, and depending on the conditions, a single type of mold spore can be any number of colors. It’s extremely difficult for a homeowner to detect what type of mold is growing in their home and whether or not that type of mold poses a danger to your health.

A lot of people are sensitive to mold spores—they may trigger allergy and asthma symptoms when inhaled. Typically, the mold found in homes is not toxic, but it can still present a health risk. There’s no real standard for a mold level that is ‘okay’ or ‘safe’—every individual reacts differently to mold. 


Health Risks

According to a Mayo Clinic study conducted in 1999, 93 percent of chronic sinusitis cases were attributed to mold. Children, babies, the elderly and people with weakened immune systems can be more sensitive to the effects of mold exposure. If anyone in your home is experiencing headaches, sinus problems, sore throats or other respiratory symptoms speak to your doctor. The cause could be mold.


How to Know it’s Mold

In most cases, you can tell if you have mold by a musty smell and black stains. Other signs include water damage and black mold around baseboards, walls and ceilings. If there is a musty smell in your home but you can’t see any stains, mold could be behind your walls. In that case, I would recommend getting a certified professional home inspection done that includes thermal imaging and possibly an indoor air quality assessment that includes mold testing.


Treating Your Mold Problem

If you find a small amount of mold that covers an area 10 sq. ft. or less, then you can typically remove it yourself. Use a solution of strong soap or detergent and water. I use Concrobium Mold Control, which requires no scrubbing and kills mold at the root, not just the surface. Whatever you use, remember to wear the proper protective gear, such as goggles or safety eyewear, a mask and gloves, and keep the area well ventilated. And do not use bleach! Not only is bleach toxic, but the mold will come back.

If the mold in your home covers an area more than 10 sq. ft., or if there’s sewage involved, bring in a professional remediation company. Any surface with over 10 sq. feet of mold should be cleaned by licensed professionals.


If you bring in a professional, do your homework and ask the right questions. What are their credentials? What training have they gone through? What kind of professional accreditation do they have? Do they have references? Mold remediation is a fairly new industry, and like anything new, it’s the frontier. If you want to make sure the job will be done right find someone with IICRC certification—Institute of Inspection Cleaning and Restoration Certification. 

About the Author

Mike Holmes, professional contractor and TV host, is working with Associa to refine the standards and protocols that today’s Homeowner’s Associations use to Make It Right™ for their homeowners. He brings more than 35 years of experience in renovations, construction, and inspection services, and is best known as the contractor and host of “Holmes on Homes” and “Holmes Makes It Right” where he rescues homeowners from repair and renovation disasters.