Can a Mold Infestation Decrease the Value of Your Home?

Audrey Bruno
Written by Audrey Bruno
Updated January 10, 2022
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Photo: Robert Crum / Adobe Stock


  • Mold begins to form 24–48 hours after water exposure.

  • Mold growth can cause health problems, decrease resale value, and be expensive to remediate.

  • It costs around $2,200 to hire a mold remediation pro.

  • Find out if you have an infestation by watching for visual clues, unpleasant odors, and allergic reactions.

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Once a mold infestation has taken over, you can expect to take a loss on the value of your home. The best thing you can do is keep your eyes, ears, and nose open to any new developments so that you’re able to spot mold growth while it’s still small enough to manage. Use this guide to keep mold infestations at bay and what to expect if you’re already past the point of no return.

Can You Sell a House With Mold Growth?

While it’s technically not illegal to put a mold-infested home on the market, you may have a hard time finding a buyer. In fact, a study in The Appraisal Journal said that up to 50% of bidders walk away once they find out about a mold infestation, even if it’s remediated. 

Some states require you to disclose mold issues, while just as many others don’t. So what you do is up to your discretion.

Issues That Mold Growth Creates for Homeowners

The truth is there are no bright sides to a mold issue, but dealing with it doesn’t have to feel like the end of the world. Knowing what to expect will help you be better prepared.

Decreased Home Resale Value 

There’s no getting around it: The impact of mold on home value isn’t a good one. According to the same study, researchers found that home resale value dropped an average of 20% to 37% for both minor and major mold problems. The bigger the issue, the larger the loss was likely to be. According to the study in The Appraisal Journal, homeowners could only sell their homes for half as much as they originally paid in some extreme cases. 

Health Problems

Mold exposure can lead to a number of physical ailments, like allergic reactions, skin irritations, and asthma attacks. Some strains, like mycotoxins, can even be lethal. 

Costly Mold Remediation

Getting rid of mold is an expensive procedure that doesn’t ensure perfect results. You’ll pay an average of $2,200 to hire a top-rated mold remediation pro near you. But you may be able to reduce the labor fee by following this mold removal and prevention guide to remove mold yourself if you can do so safely.

Know the Difference Between Toxic Mold and Mildew

A lot of what we think of as mold is actually nontoxic mildew, which is common to find lurking in bathrooms and damp basements. Fortunately, mildew isn’t any cause for major concern aside from its unpleasant smell, though it should be dealt with to ensure it doesn’t eventually develop into something more dangerous.

On the other hand, you can almost always distinguish toxic mold by its color, which is dark and black compared to the yellows, grays, and whites of mildew. Known colloquially as black mold, this category of organic matter can contain everything from relatively harmless penicillin to respiratory illness-causing Stachybotrys. 

Find Out If You Have a Mold Infestation

Though it might seem like finding toxic mold would be easy, it’s not always straightforward to differentiate it from its harmless counterpart. Watch out for these indicators to know if a mold infestation is what you’re dealing with. 

  • Visual evidence: It’ll look discolored or have black patches and cottony, speckled growth on walls or furniture.

  • Unpleasant odors: It’ll smell musty or earthy, sometimes like rotting produce. 

  • Allergic reactions: If anyone in your household experiences symptoms like coughing, sneezing, congestion, nose or throat irritation, and skin rashes, this could be a sign that you have a mold issue on your hands.

When Can Mold Become a Problem in the Home?

Some mold growth in a home is actually natural and nothing to worry about. You’ll know that mold becomes a problem in your abode if those visual indicators, bad smells, and adverse health reactions occur. The more quickly a serious mold issue is dealt with, the less of an impact it’ll have on both the resale value of your home and how you feel in it. 

If you live in a damp climate or have rooms that are especially prone to humidity, do what you can to minimize the risk of toxic mold growth by using dehumidifiers, fixing leaks, and removing noticeable mold when you see it. When in doubt, keep humidity levels between 30% to 50% to reduce dangerous mold development as much as possible. 

How to Remove Mold to Help the Resale Value 

Because mold growth can’t happen without moisture, water damage is at the root of most infestations. These are the various factors that make mold spores more likely to occur. 

Roof or Plumbing Leaks

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Mold begins to form after 24 to 48 hours of water exposure, so repair any leaks or cracks in the vulnerable areas before time runs out. Even a temporary fix—like patching up a crack in the ceiling or avoiding water use in certain areas—will be enough to prevent mold growth until you’re able to hire a top-rated local plumber or take the time to repair it yourself properly. Take care to dry everything completely when you’re finished.


Water damage from flooding needs to be dealt with effectively and immediately to limit mold growth. Depending on the size of the affected area, it may be impossible to prevent its development entirely. But working fast and calling an emergency cleaning service near you will help you avoid unnecessary damages.

Excess Humidity 

While having a bit of humidity in your home can be a good thing, too much is more likely to harm than help. Control humidity levels in your home with appliances like exhaust fans and dehumidifiers to keep mold to a minimum. And learn how to remove mold in bathroom ceilings.

Poor Ventilation and Insulation

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Photo: Andrey Popov / Adobe Stock

If your windows don’t shut tightly and air doesn’t circulate properly, moisture is more likely to seep in and get stuck in places where it doesn’t belong, like in your AC unit. The last thing you want to worry about is mold spores filling the air every time you adjust your home’s temperature. 

If you do have this problem, there are cost-effective ways to DIY mold removal from your AC.

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