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Moldy Crawl Space

A moldy crawl space can be very frustrating for your home. What do you need to know about the problems that may occur with a moldy crawl space?

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If there’s one thing you don’t want to see in your crawl space, it’s mold. Mold in the crawl space can be a huge problem, especially because mold tends to indicate other problems as well. If you aren’t quite sure what you’re dealing with in your crawl space, but you think it might be mold, you must tackle that problem as soon as you can. Here’s everything you need to know about mold in your crawl space and the associated concerns.

Mold on crawl space on wooden beams
Mold needs a moist environment to thrive. Several different types of mold can grow in a damp crawl space.

The Causes of a Moldy Crawl Space 

First off, you might want to know what causes a moldy crawl space in the first place. Although the base problem is always water, there are many different ways in which it can manifest. That includes all the following. 

  • Standing Water 

If you have standing water in your crawl space, you’re almost certainly going to end up with mold. Mold typically needs at least around a 70% crawl space relative humidity level to grow and thrive. However, if you have standing water in your crawl space, you have many areas of 100% relative humidity, which is where the water sits. 

This is going to cause a great place for mold to grow. All you need is for a few spores of mold to come into your crawl space. If you have that mold in your crawl space at all, it’s going to multiply for as long as you have standing water. The only way to get rid of it is to make sure you have no more standing water in your crawl space. 

  • Sudden Flooding 

Did you recently have an issue with flooding in your crawl space? Maybe you had a severe weather event that caused flooding, maybe there was a leaky pipe that created a flooding event in your crawl space, or you had some drainage issues for a short period that created flooding problems. 

Regardless of the reason for the flooding, you need to address these flooding concerns early on. Flooding water can easily turn into standing crawl space water, which can create crawl space humidity concerns including but not limited to crawl space mold. Sudden flooding is a problem, but it’s one you can thoroughly tackle if you have the tools for it. 

  • High Crawl Space Humidity 

Do you have high levels of crawl space humidity? Crawl space humidity issues can cause plenty of crawl space concerns. Plus, these humidity issues could arise from all sorts of locations, ranging from just having a dirt floor in your crawl space to having cracks in your crawl space walls that are allowing water vapor inside. 

When you have high crawl space humidity, you’re going to have plenty of other crawl space concerns. Crawl space mold may even be the least of your concerns because you’re going to end up with other humidity-based concerns. That may include structural issues, high indoor humidity, and other concerns, all pointing to the fact that you need to fix high crawl space humidity as soon as possible.

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Our Foundation Recovery Systems’ Dehumidifier Dehumidifier System reduces overly humid conditions to protect your family and your home from the harmful effects of moisture and mildew.

What Problems Can a Moldy Crawl Space Cause? 

Is a moldy crawl space a problem? Although mold in your crawl space probably isn’t going to be toxic, that doesn’t mean it’s safe, either. Here’s what you need to know about these secondary moldy crawl space concerns. 

  • Allergies and Asthma 

One of the biggest problems that you’ll probably notice with crawl space mold is the fact that you’ll almost certainly have plenty of allergy and asthma issues to sift through as this crawl space mold starts to grow. Mold may not be toxic most of the time, but it contributes to your allergies and asthma even if you don’t notice at first. 

The problem is most pronounced with homeowners who already have severe allergies, asthma, and respiratory issues. However, even if you don’t think you have allergies, you might end up with allergic reactions to the mold in your crawl space. It’s common for crawl space mold to cause allergic reactions even in individuals who don’t know they’re having allergic concerns. 

  • Off-Putting Smells Throughout the Home 

A musty smell may be something that you assume is normal for your crawl space. You may even assume that it’s a common occurrence for other areas of the home as well. However, these off-putting smells, whether they’re in the crawl space or throughout the home, tend to indicate mold problems. 

The truth is that there’s no such thing as a “normal” musty crawl space smell. If your crawl space or home smells musty or dusty, it’s because there’s a problem. That smell indicates that there’s an issue, and you need to address it as soon as you can. Off-putting smells throughout your home can be frustrating, annoying, and indicative of a crawl space concern. 

  • Structural Concerns 

Because mold and mildew eat through organic material, you can have plenty of very serious structural concerns when you allow mold and mildew to thrive in your crawl space. Most structural elements of your crawl space utilize organic material, such as floor joists, which typically use wood for maximum strength while also allowing for some movement. 

Structural concerns are one of the most important things that can occur in your crawl space, and you need to make sure you know how to manage those concerns. If you have mold and mildew in your crawl space, you should check to make sure your crawl space doesn’t have structural issues because of those mold and mildew problems.

Mold in Your Crawl Space


A moldy crawl space is frustrating for sure, but one of the most frustrating things about having a moldy crawl space can be when you don’t understand what’s happening. Fungus requires water to grow, so here are the main reasons you probably have a moldy crawl space. 

  • High Crawl Space Humidity 

High crawl space humidity can be dangerous. There are many reasons you might have high crawl space humidity, including open crawl space vents, a dirt crawl space floor, or just general high levels of humidity. Because mold thrives above 60-70% relative humidity, all the above are a great starting point for mold. 

The most common causes of dampness in a crawl space are uncovered vents, bare dirt floors, cracks in the walls or foundation of a property. In most cases, waterproofing and encapsulation can nip a crawl space’s damp problems, and thereby its mold problems, in the bud very quickly. If, however, the dampness comes from structural damage, it will need to be addressed. 

  • Standing Water in the Crawl Space 

The other potential reason for mold in your crawl space is if you have standing water in the crawl space which is not being efficiently drained. The standing water will inevitably turn into high levels of humidity as that water evaporates. Plus, the area right around the standing water will always have high enough levels of humidity to maintain mold growth. 

As such, even a single puddle can damage the environment in your crawl space. Ensuring that you have efficient drainage options in place, however, will prevent standing water in your crawl space and keep relative humidity low. Encapsulation, too, will help to minimize the impact of flooding and standing water in your crawl space.

Some homeowners might think that a moldy crawl space isn’t necessarily important to fix. However, they couldn’t be further from the truth. Fixing your moldy crawl space should be at the top of your list, and here’s why. 

  • Strange Smells 

You may have heard that strange smells are just a normal part of having a crawl space, but that’s not true. Strange smells don’t have to be a normal part of having your crawl space; they’re typically indicating that you have mold and mildew problems in your home. Your crawl space shouldn’t smell much different than the rest of your home. 

If you are tempted to view musty smells in your crawl space as a non-issue, keep in mind that mold and musty smells can migrate into the rest of your home over time. They will do this either through your HVAC system (where certain kinds of mold can thrive) or as a part of the natural circulation of air that occurs when warm air rises and draws cool air from your crawl space upwards. 

  • Structural Damage 

Structural damage is a problem that mold and mildew can both create and be a result of. As mold and mildew start to eat the organic material they grow on, they’ll begin to cause structural damage. It can take a while for this damage to show up, of course, but it’s very much a threat to your structural stability. At the same time, mold can also be useful. 

That’s not to say that mold in your home is desirable, but rather that mold and mildew can be a useful indicator of structural damage at play. By focusing on areas where mold formations are particularly strong, you can identify where moisture and humidity are most concentrated. As such, they can help professionals to identify trouble spots.

Fixing your moldy crawl space is certainly important, but it can also be very time-consuming and difficult. Some homeowners might wonder whether there’s an easy way to fix their moldy crawl space. Here’s how to go about that. 

  • Reduce the Amount of Humidity in the Crawl Space 

The first option is to reduce the overall levels of humidity in your crawl space. If you already have crawl space encapsulation, you may just need a dehumidifier to control moisture levels in this space. In many cases, this will be enough to prevent mold from forming or spreading, though sometimes a little more help may be needed. 

Humidity, of course, is one of the key things needed to allow for mold formation, so if you take steps to control humidity, you could avoid ever having to deal with mold. However, some species of mold can thrive in relatively low humidity (compared to other species) so total encapsulation is often the only way to completely remove the possibility of mold. 

  • Crawl Space Encapsulation 

If you have a wholly unencapsulated crawl space, you might need to invest in crawl space encapsulation to protect your home from dampness. This can include adding a crawl space vapor barrier, covering your crawl space vents, and adding a dehumidifier. It may be beneficial for homeowners who have moisture coming in from several places. 

Crawl space encapsulation is often recommended as a matter of course for any property these days because of the many benefits that the process offers. As well as keeping out moisture and mold, and reducing pests’ interest in the space, full encapsulation can lower your energy bills, stabilize the temperature in your property, and add useful storage space.

Fixing your moldy crawl space should be a priority, and that means you shouldn’t be trying to fix it yourself. You must bring someone in to fix your moldy crawl space, even if you’re tempted to try and fix it on your own. 

  • The Problem with Fixing It on Your Own 

When you try to fix your moldy crawl space on your own, you’re very likely to miss important warning signs of deeper structural damage. Moisture can come into your crawl space in the most subtle of ways, and usually, there is more than one cause. If you don’t know how to fix your moldy crawl space, you shouldn’t try in the first place. 

If you do attempt to fix your dampness problems alone, you may end up covering up damage or co-occurring issues which will then continue to grow unobserved. If this happens you will find that you get a much higher repair bill further down the line (as well as a massive headache). As such it is in your best interests to call in a professional early. 

  • Getting Help from an Expert 

Rather than trying to DIY a moldy crawl space fix, you can opt for a fix from an expert at Foundation Recovery Systems; our team is highly qualified and capable of making sure you get a tailored solution. With an in-depth analysis and personalized information about your unique problems, Foundation Recovery Systems can help you fix your moldy crawl space permanently. 

As well as guaranteeing a complete solution, professional mold treatments are safer for you and your home. After all, the chemicals involved in mold removal are strong and fairly dangerous if they are used improperly. As such, it is far safer and more effective to just let a remediation professional remove mold and mildew from your property.

How Do I Fix a Moldy Crawl Space? 

The most important question you might end up asking yourself is how to fix this problem. If you’ve already been experiencing issues with a moldy crawl space, you do need to find a new way to fix the problem. Here’s what you may want to do to fix your crawl space mold. 

  • Maintain an Arid Crawl Space 

One of the best things you can do to manage your crawl space is to make sure your crawl space stays as dry as possible. High levels of crawl space moisture will most commonly attract crawl space mold, which means low levels of crawl space moisture will make it more difficult for crawl space mold to grow and thrive. An arid crawl space is your best bet here. 

However, you also don’t want to try to reduce your crawl space moisture so far that it might end up causing the opposite problems. Although crawl space moisture that’s too low is a very infrequent problem, that doesn’t mean it’s not a problem at all. Low crawl space moisture can cause other problems, which is why it’s a good idea to talk to a crawl space repair expert about your moisture concerns. 

  • Remove Mold as Soon as Possible 

The moment you notice mold in your crawl space, you should do whatever you need to do to make sure it’s no longer a problem. The longer you allow mold to grow and thrive in your crawl space, the more damage it will do to the crawl space and the area around it. You need to remove that mold as soon as possible, ideally before it has a chance to do any lasting harm to your crawl space. 

The mold removal process can be very complicated. If you’re looking to remove mold in your crawl space, you’re going to need to make sure you’re getting all of it. This is why it’s typically not enough to just scrub it down on your own. You need to make sure you’re talking to a mold remediation specialist about the options you have for removing the mold in your crawl space for good. 

  • Ensure Your Waterproofing Measures Are Complete 

There are many different crawl space waterproofing measures you might take part in. For example, you may have interior drains, a sump pump, crawl space encapsulation, crawl space vent covers, and much more. However, a waterproofing measure won’t do anything unless you’ve followed through with a complete waterproofing process. 

If you have partially completed waterproofing processes, you’re just as bad off as if you had no waterproofing processes at all. You may even be worse off because you may assume you have some protection that you don’t have. It’s important to talk to a crawl space repair expert to ensure that you have the best waterproofing measures out there. 

Handling Moldy Crawl Spaces with Expertise from Foundation Recovery Systems 

As you can see, there are many things you can do to make your crawl space healthier and remove mold. It’s important to remove crawl space mold because it can have all sorts of impacts, including exacerbating your family’s allergies, asthma, and other respiratory problems. 

If you’re looking to maintain a healthy crawl space, your best bet is to talk to a crawl space repair expert. A local expert with Foundation Recovery Systems will be able to manage your crawl space issues, no matter what they are. That includes mold, water, humidity, and much more. With their help, you’re more likely to end up with a complete and total fix for your crawl space concerns.

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