White Mold in Your Crawl Space? Here’s How to Stop It for Good
If you’ve spotted white, fuzzy patches in your crawl space—or noticed a musty smell drifting into your home—you’re not alone. White mold is a common issue in damp crawl spaces, especially in areas with high humidity or seasonal moisture. And while it’s not always as infamous as black mold, it can still cause serious damage to your home’s wood structure and even impact your indoor air quality.
At Groundworks, we’ve helped thousands of homeowners take back control of their crawl spaces. Here’s what you need to know and how we can help protect your home for good.
What Is White Mold?
White mold is a type of fungus that appears as a powdery or fuzzy coating. It can look white, gray, or green depending on the surface it grows on. Like all mold, it thrives in damp, dark places with poor air circulation—making crawl spaces an ideal environment.
If your crawl space has wood beams or joists, mold has a built-in food source. Left alone, it can slowly eat away at your home’s structure.
Is White Mold Dangerous?
Yes, white mold can be a serious threat—even if it doesn’t look alarming at first. Over time, it breaks down the wooden supports beneath your home. That can lead to sagging floors, musty odors, and even structural damage.
It can also impact your health. Mold spores may trigger allergy-like symptoms, especially for kids or older adults. If you’ve noticed sneezing, itchy skin, or worsened asthma in your household, mold in your crawl space could be part of the problem.
What Causes White Mold in a Crawl Space?
White mold needs three things to grow: moisture, a food source (like wood), and poor airflow. Crawl spaces often provide all three.
Here are some common culprits:
- High Humidity: Especially in the summer when warm, moist air enters through open vents.
- Plumbing Leaks: Even a slow drip can raise humidity levels quickly.
- Poor Drainage: Clogged gutters, broken downspouts, or grading that slopes toward your home can allow water to pool near the foundation.
- Unsealed Vents and Dirt Floors: Openings allow outside air and moisture to enter, while exposed soil releases vapor into the space year-round.
Signs You Might Have White Mold
White mold isn’t always easy to spot, especially if you don’t go into your crawl space often. But your home may be sending signals:
- A strong, musty smell—especially after it rains
- White or gray spots on wood or insulation
- Discoloration or staining on baseboards or floors
- Increased allergies or breathing issues at home
- Soft, sagging floors above the crawl space
How to Get Rid of White Mold—and Keep It Gone
Getting rid of mold is only part of the solution. To stop it from coming back, you need to address the moisture problem at its source.
Here’s how our crawl space experts can help:
1. Crawl Space Encapsulation
Encapsulation seals off your crawl space from outside moisture. This includes:
- Installing a thick vapor barrier across floors and walls
- Sealing vents and gaps to block humid air
- Adding a dehumidifier to keep the air dry year-round
Once sealed, mold can’t survive—and your home stays cleaner, drier, and healthier.
2. Fix Leaks and Cracks
Even small plumbing leaks or hairline cracks in your foundation can let moisture seep into your crawl space over time. Our team carefully inspects your pipes, walls, and floor for signs of water intrusion, and makes targeted repairs to stop the problem at its source. Sealing these trouble spots is a key step in keeping your crawl space dry and mold-free.
3. Improve Drainage Around Your Home
If water is pooling near your foundation after a storm, your drainage system may need attention. We’ll evaluate your gutters, downspouts, and landscape grading to see how water flows around your home. Then, we’ll recommend fixes—like extending downspouts or reshaping the soil—to direct rainwater safely away from your crawl space.
Professional Crawl Space Repair You Can Trust
White mold in your crawl space isn’t just an eyesore—it’s a sign your home needs attention. Groundworks is here to help. We’ll inspect your crawl space for free and install lasting protection to prevent mold from returning. Contact us today to schedule your free crawl space inspection.
White Mold FAQs
It depends on the cause and your policy. Mold from sudden, accidental water damage is often covered, but long-term moisture issues typically aren’t. Check with your provider to be sure.
You may have heard before that mold is dangerous. Truthfully, mold absolutely can be a severe problem, but it might not be for the reasons you’re thinking. If you have mold in your basement or crawl space, you might end up with a variety of problems. That can include these concerns.
- Health Risks
The health risks of mold are probably what you think of first and foremost when considering mold issues. Mold can cause a stuffy nose, sore throat, coughing, wheezing, burning or itchy eyes, skin rash, fever, and shortness of breath. Homeowners who are immunocompromised, asthmatic, or suffer from chronic lung disease are the most vulnerable to mold growth, but anyone can have a severe reaction.
Most types of mold, including so-called “toxic mold,” aren’t going to kill you. They may, however, create a more severe reaction that can be extremely uncomfortable to live in. If you want to be safe, you need to clear out the mold early on. Your home should be comfortable, not just non-toxic, which is why it’s essential to get rid of all types of mold.
- Structural Problems
You can also see structural problems with your home because of mold. Mold eats organic materials, which means that as the mold grows in your basement or crawl space, it’s going to start eating away at it. This can lead to serious structural concerns overall.
This problem can mimic the symptoms of wood rot. When they encounter issues with bouncy floors, for example, most homeowners will immediately worry about wood rot. However, in some situations, problems with mold and mildew can cause these bouncy floors. Regardless of the reason, you need to fix these problems early on.
Because mold requires spores to start growing, it needs to come from somewhere. You might wonder how mold even gets into your home. Knowing a bit more about how mold gets into your home is a useful way of avoiding it.
- Through the Air Outside
Mold spores are small enough to travel through the air. This means anytime you open a door, window, or vent, you can potentially invite mold spores in. Mold spores can also circulate in your HVAC system. Most of the time, air filters can continuously filter these out, but there’s always a chance that a single spore can get past the filter.
In general, there’s no way to altogether avoid mold spores getting inside your home. It’s all about whether you allow those mold spores to grow, which requires that you keep things in your crawl space as healthy as possible.
- Clothing and Other Items
You or a member of your family can also unknowingly carry mold spores on your clothing, shoes, bags, boxes, or other belongings. When you store things in your basement or crawl space, for example, it’s possible that the items you’re storing already have mold spores.
This is another reason that you must maintain an environment where mold and mildew simply won’t grow. Your best bet is not to try and avoid any mold spores coming inside your home in most situations. Instead, make sure that the crawl space and the rest of the home won’t allow for mold spores to grow.
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