If you think your home is mold-free, you’re probably wrong.
As a microscopic fungus, mold can be found everywhere — in soil, the air, food and even our homes. Mold spreads to new locations by releasing spores into the air. It can travel through an open window, flow through your air conditioning or follow you inside through the front door.
As scary as it is to know mold is lurking everywhere, mold only becomes dangerous when it attaches to organic material and spreads due to damp conditions.
“Mold grows on any type of porous material if humidity is present, but damp and dark areas can grow mold at a faster rate,” says Spencer Zeyer, owner of Pure Maintenance Florida, a mold remediation company that serves Orlando, Jacksonville and Daytona Beach.
This makes buildings filled with organic matter like wood and drywall a perfect environment for mold growth. Like many other first-time homebuyers, I learned this the hard way.
Shortly after my husband and I moved into our first home in St. Petersburg, Florida, I started having odd health problems. My eyes and lips were swollen when I woke up. I had headaches, random body hives, ear infections, extreme fatigue and trouble focusing. After visiting the doctor, we discovered the culprit was mold.
Despite renovating the entire interior of the home and finding no obvious signs of mold, my illnesses helped us reveal a massive mold problem in our crawl space. Most homeowners think they only have a mold problem if they can see it, but often mold is lurking behind the scenes.
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How Prevalent is Mold in Homes?
Mold is extremely prevalent in homes and other buildings. From offices, schools, apartments and single-family housing — no property is off-limits from mold. In a 2022 report, the National Institute for Occupational Safety and Health Centers for Disease Control and Prevention estimated that around 47% of all homes in the United States have some mold or dampness, based on several published studies.
Where your home is located will largely determine the likeliness of mold. “In the desert of Arizona, your maintenance levels are pretty small compared to the rest of the country,” Zeyer says. “In Florida, the attention or care you have to give your property is much higher. Depending on the location and the type of construction, you have situations where mold loves your home because of how it’s built.”
How to Tell if Your Home Has Mold
One of the most obvious ways to tell if your home has mold is damp, dark or fuzzy growth in your home. This is what Lorraine Castro, owner of Uptown Realty Group, found in her home in Ormond Beach, Florida.
“I went to grab my jacket out of the closet for a motorcycle ride and was shocked when I saw everything was covered in mold,” Castro said. “We had to throw out some of our shoes and jackets that couldn’t be washed and bought a dehumidifier that day. After 24 hours of dehumidifying, we had collected just under three gallons of water.”
Seeing mold is a clear sign, but sometimes you can smell mold, too. It can have a musty or mildew scent, and certain species of mold can also give off a pungent cat urine odor or cooked oil.
Health issues can also be a warning sign, whether you see mold or not. People’s reactions vary depending on individual predispositions to mold and the type of mold growth. Some people have no symptoms. Others can have a sore throat, itchy eyes, memory loss, heightened asthma problems, headaches, sneezing, skin rashes and in some cases autoimmune disease from prolonged exposure.
Because medical issues can vary so greatly, it doesn’t matter which type of mold may be growing or how you’re feeling, all visible mold growth in your home should be removed and the source of moisture repaired to ensure growth does not occur again.
What Causes Mold to Grow in Your Home
Since moisture is the catalyst for mold growth, you need water intrusion or damp conditions to create a mold problem. It can be caused by a pipe that breaks, flooding from rain or a major storm, water leaking from a faulty roof or old windows that aren’t sealed well, or from a humid crawl space, attic or basement.
The size of the problem is less important than your ability to repair the source of moisture. Many homeowners think if they see mold in an isolated area that’s where the mold issue is. But you need to identify the root cause, exactly where the water or humidity is coming from.
In humid states like Florida, Zeyer says, mold is most prevalent in the HVAC system, which few homeowners routinely inspect. “It’s damp and collects dust making it a perfect place for mold to grow,” he says. “If the house is as clean as clean can be and there is no visible presence of mold, but you’re getting sick, it’s likely an HVAC mold issue.”
Even if the mold is not causing health problems, you should address the growth and reduce moisture levels to prevent its return. Signs of mold can lead to illness over the long term and can be a major deal breaker if you want to sell your home.
What To Do if You Discover Mold in Your Home
To make sure you address any evidence of mold growth appropriately, it’s best to talk to a professional who specializes in inspecting homes for mold.
Remediating mold isn’t a one-size-fits-all solution. A mold expert can help you identify the types of mold, the severity of the issue and the best way to address it. Just make sure they’re an impartial source.
Charles Gallagher, an attorney specializing in toxic mold litigation in St. Petersburg, Florida, recommends selecting two separate companies to perform the inspection and remediation to ensure impartiality and, even more important, to make certain the inspection has merit.
“You want to make sure that you have two different sets of folks involved, as opposed to one person coming out who is a drive-by repair, handyman kind of service who doesn’t understand the scientific aspect of it,” Gallagher says.
If you haven’t yet closed on a home and you find mold, it’s typically a good idea to hire a professional to assess the situation.
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How to Get Rid of Mold in Your Home
The spectrum of mold growth removal can range from a simple at-home cleaning to a heavy-duty remediation process that requires residents to leave until conditions are safe enough to inhabit the home again. For spaces that are just a little too humid, a dehumidifier that’s the right size will help to keep moisture levels in the air below 60%, which is the threshold for many types of mold to grow.
Zeyer says hydrogen peroxide is best to address mold in small amounts in common areas like shower grout. While bleach is a common suggestion online, Zeyer recommends avoiding it. While bleach kills mold on nonporous surfaces such as glass or metal, it can actually contribute to mold growth on a porous surface, such as drywall.
The key point, Zeyer says, is to address the root cause properly. Mold produces mycotoxins, which are what make people sick. When agitated they can spread into other areas of your home, so remediation of mold, and thus mycotoxins, needs to be handled carefully.
Professional remediators treat serious mold issues with dry fog and specially designed products to eliminate mycotoxins from the home. You can get a free environmental consultation from most mold remediation companies. Sanitizing can cost $350 or less if you do it at home, while a full-service duct cleaning can cost over $1,500.
Whole home mold remediation projects typically cost several thousand to tens of thousands depending on the severity of the problem, its location and cause, and the process of removing the mold. In some cases, the company will need to remove areas of walls, sand wood or section off impacted areas to keep the mold from spreading.
Tips to Prevent Mold From Happening
If you experience water intrusion from flooding, a roof leak or pipe bursting, address the issue immediately. Ensure the area is properly dried out and use mold sprays or hydrogen peroxide to reduce the chances of mold growing.
The best thing to do is keep your home dry. “The ideal humidity is below 60% and above 30%, but we say the goal is 55%,” Zeyer says. Use proper dehumidifiers or a humidity meter to monitor levels in the home. Also, regularly maintain the HVAC system by changing out the filters and running it often.
You also want to address ongoing water intrusion issues like flooding in the crawl space. If moisture constantly gets into or under the home, you can remove the mold, but it will return quickly.
Selling or Buying a Home With Mold
Any major defect can break a deal or have a big impact on negotiations when buying a home, and mold is no exception. Aside from the potential health issues, mold will continue to devalue your property until the problem becomes so rampant that the home is uninhabitable. Nobody wants to purchase a seller’s mold issue, whether it’s impacting the air quality or not.
Regardless of whether you’re on the buying or selling end of the transaction, be sure you understand the laws on informing a purchasing party about home defects. “The law in Florida and in most states, generally, is that you have to disclose all known defects and any issue which materially affects the value of the property,” including evidence of mold in the home, Gallagher says. Providing the details of a previous inspection, mold lab test results or even simply stating that stains on a wall might be mold could be considered sufficient disclosure.
Evidence of mold will change the way sellers are able to negotiate, but it’s better than being found guilty of nondisclosure. How the buyer will want to proceed varies depending on the individual and where you live.
The buyer and seller can agree upon a reduction in the sale price, leaving the buyer to make repairs. In Florida, for example, there is a state standard that the seller is expected to cover for needed repairs to the home — 1.5% of the sale price — unless both parties agree it’s not necessary or they agree the repair cost will be more.
The other option is to negotiate that the seller make repairs before closing or before the buyer takes possession of the home, which Gallagher says he would personally prefer: “I’d rather have a seller make the remediation to it, and then when I take possession of the property, it be mold-free, or in pre-loss condition.”
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Is Your Home a Health Risk? Why Mold May Be Lurking in Your Home originally appeared on usnews.com
Update 04/11/24: This story was published at an earlier date and has been updated with new information.
