Skip to Main Content
Crew installing dehumidifier in crawl space

Crawl Space Humidity

Crawl space humidity is a common problem, but many homeowners may not know what to do next.

Schedule A Free Inspection

The somewhat changeable climate that homes in Minnesota, North and South Dakota, and eastern Montana have to deal with means humidity is a real problem for many people. Older homes, in particular, can struggle with dampness and humidity in their crawl space as a result of uncovered vents and poor insulation. A humid, damp, or flooded crawl space can cause many different issues that can impact your property and health.  

Understanding how humidity enters and affects your property and crawl space is all-important to making sure your home stays safe and dry.  

How Humidity Takes Root in Your Crawl Space 

Dampness and humidity can access your home in many ways, and not all these entry points are the result of damage. When a property is first built, it is essentially a large, wooden box with few, if any, holes that lead to the outside world. Your crawl space, by contrast, will be a concrete enclosure that acts as a buffer between your property floors and foundation. Then, of course, the work of making this shell a house begins and contractors cut holes in a property to run wires and pipes, install HVAC systems, and install fixtures and fittings. While all these openings and joining points are sealed, the expansion and settling of your house over time can cause these seals to weaken or break. Other potential points of entry for dampness and humidity in your crawl space are:   

  • Uncovered Vents  

If you have an older home, it is very likely that you will have crawl space vents. These were installed in properties because they were believed to prevent or help in the management of dampness, but studies have since shown that they actually exacerbate the issue. Crawl space vent covers can help to prevent and manage this, however, and are relatively affordable and easy to install.  

  • Cracks in the Walls  

If your crawl space walls have cracks in them, water is sure to start seeping through, and in winter this water will freeze, expand, and let more water in during the thaw. This will cause a huge rise in humidity and dampness in your crawl space.  

  • Foundation Heave  

Foundation heave can occur for a number of reasons. From sudden cold snaps causing the earth beneath your home to heave upward to tree roots invading, any kind of serious upward pressure on your property foundation can cause it to heave upward and crack. This will allow water to seep up into your crawl space. If the cracks are severe and the soil is saturated, you could even end up with standing water.   

  • Bowed Walls 

Seriously damaged walls can begin to lean, tilt, or even bow. When this happens, you will, of course, have bigger issues to worry about than dampness, but it will also let in water and humidity.  

  • A Cracked or Damaged Foundation  

Foundation problems start in the soil. Whether it is too dry or too wet, moisture management issues can cause the soil under your property to become incompetent. This means it becomes unable to support the weight of your property or provides inconsistent support; this will either result in subsidence or settlement.  

Once dampness and humidity get into your home, it will percolate and start to cause additional problems for you. Furthermore, it won’t stay limited to your crawl space but will have an impact on the climate of your home as a whole. While water and dampness in your crawl space are going to have the biggest effect upon that space, it will have a cumulative effect on your property as a whole. After all, heat rises and when it does, it pulls cooler air in to fill the space. This means the colder air from your crawl space will be pulled up into your home, bringing dampness with it. Humidity and dampness can also travel through your home via the ducts and vents in your HVAC system.   

How Humidity Affects Your Property

Humidity and dampness from your crawl space can have a huge impact on your property as a whole and will contribute to many different issues. High levels of crawl space humidity can lead to many issues such as:   

  • Rot  

Dampness and humidity can easily lead to organic materials like older types of cavity insulation and wood rotting. This is not only unpleasant and unhealthy, but it can be dangerous; if the supports that keep your property floor up rot, they will lose stability. This can lead to sagging, tilting, or even collapse in your floors.  

  • Mold and Mildew  

Mold and mildew are pretty much a given in a property with a damp, humid crawl space. Different breeds of mold take root in different environments and some can be damaging to your skin, eyes, and respiratory system.  

  • Bad Odors  

Dampness, rot, and mold are notorious for creating musty, unpleasant smells. This musty odor will spread through your whole property and make the environment generally unpleasant. 

  • Higher Utility Bills  

Humidity and dampness make it harder for your HVAC system to condition and regulate the temperature and climate in your home. This can increase your energy consumption and bills quite considerably.  

These are just some of the issues that can be caused by uncontrolled dampness in a property’s crawl space; there are many other, more complex, problems that dampness can add to and exacerbate. Thankfully, many of these issues will subside or fade when humidity levels are lowered.  

Controlling Crawl Space Humidity and Dampness  

Unless dampness is being caused by serious foundation or structural damage, it is very easy to deal with. If you do have structural issues contributing to the dampness, however, you will need to address this before you can truly bring the humidity levels under your control. Of course, humidity control isn’t the main reason you should deal with structural damage; structural problems can escalate with alarming speed and should be dealt with as soon as possible.  

If you do not have structural problems to address, dealing with excess humidity and dampness can be surprisingly easy. Here at Innovative Basement Authority, we specialize in crawl space repair and encapsulation. Our team is highly trained and skilled, we use the best possible products and provide high-quality results to all our customers no matter the scale of the job. For controlling, reducing, or eliminating humidity and dampness in a crawl space, we suggest the following repair solutions:   

  • Insulation  

Insulating your pipes will prevent freezing, bursting, and flooding, but insulating your crawl space walls will lower levels of humidity and dampness as a whole. This is mostly because of the water-resistant nature of foam insulation; proper insulation will create a protective shield between the interior of your crawl space and the outside.  

  • Vapor Barrier Installation  

Installing a vapor barrier is one of the most effective humidity and dampness control measures you can deploy. By encapsulating your crawl space, you will create a clean, dry, and temperature-controlled environment.  

  • Drainage Mating and Interior Drainage  

Drainage matting can be placed on the floor under the vapor barrier to add an extra layer of protection. These are best paired with interior drains, which will collect and redirect any water that does make its way inside.  

  • Sump Pump Installation  

When installing drainage matting and interior drains, it is essential to pair these with a sump pump system. This is an excellent and effective moisture control measure that will actively remove water from your property.  

  • Dehumidifier Installation  

If you do not have standing water, but your crawl space is excessively damp even after you have sealed and encapsulated it, installing an energy-efficient dehumidifier is a fantastic solution. A dehumidifier will create a hygienic and comfortable climate in your crawl space, and this will positively impact the environment of your house as a whole.  

  • Vent Cover Installation  

There’s no point in insulating and encapsulating your crawl space if you do not cover your crawl space vents. Vent covers are durable and incredibly effective in keeping water and cold out of your crawl space. Better still, they are cost-effective.  

These measures will prevent moisture from entering your crawl space in the first place and remove any water and humidity that does make its way into your home. As such, you will notice that your crawl space is far more comfortable and hygienic. It will also have a positive impact on your property as a whole.  

Crawl Space Humidity


Humidity and dampness can get into a crawl space in a number of ways. Water can seep in when the seals around utility induction ports weaken or break, but it can also get into a crawl space through damage to the structure.  

  • Flooding Issues 

Humidity can build up to extremely high levels in the crawl space. This is mainly due to how small and contained it is. Coupled with the fact that your fiberglass insulation can trap humidity in this space, and it is a recipe for rot and destruction. 

Not only can humidity invite mold and pests to infiltrate your crawl space, but it can also cause floods in your crawl space, too. The relative humidity of a given space is a ratio that measures the percentage of water in the air. A good level is around 50% capacity, with any more being rife for humidity issues. If it goes over 100% capacity, the humidity will condense into liquid drops and can eventually flood your crawl space. 

  • Foundation Damage  

If your foundation is damaged by frost heave, tree root invasion, subsidence, or settlement, water can seep into your crawl space. If the soil under your home is especially saturated, the damage can lead to standing water that will stink the longer you let it linger. 

Additionally, constant flooding can also cause the foundation to shift out of place and affect the rest of your home’s infrastructure as a result. The soil underneath the foundation may also be washed away during a storm, which can cause the foundation to settle and eventually crack. 

If the humidity around your crawl space is allowed to spread around other parts of your home, this can cause plenty of other issues, too. Rising humidity is commonly caused by the stack effect, which can not only make your house feel warmer, but also your energy bills to climb as well. 

  • How It Works 

When humidity gathers in your crawl space, this can cause enough problems on its own. Of course, with your HVAC system installed in this space, it can also spread this humidity to the rest of your home as well. Hot air tends to rise because it is far lighter than cool air. As a result, you might notice your home feels a lot muggier in the summertime. 

Conversely, in the winter, you might notice your floors being absolutely freezing to walk along. It may just be a lot colder in your house in general during the winter. Any cold air that gathers in your crawl space will easily push out any warmer air inside your home. 

  • Why It is Costly 

The stack effect can make it very uncomfortable to live in your own home. In the summer, you might find that turning on any fans will only spread the humidity around faster. You might then resort to cranking up your air conditioner to extremely high levels just to stay cool in your house. 

You might also find yourself turning on your heater much higher in the wintertime for the same reasons. This is what makes the stack effect so costly. Humid air is much harder to heat and cool than arid air; dampness and humidity will increase your energy consumption and your bills. These are just some of the negative side effects you could face if you do not deal with the humidity in your crawl space.  

Technically speaking, encapsulation is straightforward, but if you want to get the best possible results you should allow a professional to deal with it. A professional will ensure your solutions are deployed most effectively and that you get the best possible results. 

  • Cover Up Pre-Existing Problems  

Many homeowners think that simply covering up their crawl space will solve all their problems. Of course, this only seals up the damage still left behind in your crawl space, which will only make the damage that much worse if an expert cannot access it. 

This is why you need to leave any repairs to the crawl space experts at Innovative Basement Authority. We can easily implement any repairs your crawl space might need then install protective measures to waterproof and seal up your crawl space. 

  • Cause More Damage  

If you encapsulate your crawl space improperly, you could trap moisture into the space and actually cause more damage to your home. This could cost you far more in the long run than professional encapsulation does.  

As you can see, it is far better to make sure that encapsulation is done properly in the first place. This will not only save you money in the long term, but it will ensure you get the best possible experience and results.  

Choose Innovative Basement Authority for Humidity Control Throughout Your Home  

If you are looking to deal with the dampness and humidity in your crawl space, we at Innovative Basement Authority are here for you. While we know you have many different options when it comes to crawl space encapsulation, we know that we offer a better service at the best possible prices. Innovative Basement Authority offers free crawl space inspections and repair quotes, so you have nothing to lose!  

Once one of our highly trained experts evaluates your crawl space and home, you’ll have a better idea what you are up against and how you can better protect your living environment. If you are ready to get started, do not hesitate to contact our team to book an appointment.  

Publish Date:

Last Modified Date:

Innovative Basement Authority Service Map

We service Minnesota, North Dakota, South Dakota and Eastern Montana for basement waterproofing and crawl space repair.

Fargo, ND

1330 41st St. N
Fargo, ND 58102

Minneapolis, MN

6265 Carmen Ave.
Inver Grove Heights, MN 55076

Rush City, MN

1325 S Frandsen Ave
Rush City, MN 55069

Sioux Falls, SD

101 S. Reid Street, Suite 307
Sioux Falls, SD 57103