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open crawl space vents

Crawl Space Ventilation

Rather than benefiting your crawl space, ventilation harms this area of your home. What are some crawl space problem signs you need to look out for?

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Maintaining your crawl space is just as vital to the health of your home as any other upkeep you do. Unfortunately, the crawl space isn’t always easy to find, and maintaining the crucial components inside it can be overwhelming. That is why it is far easier for homeowners to watch out for smaller issues that may arise instead.   

Knowing how to keep an eye out for any smaller problem signs that negatively impact your home can help prevent any extensive damage from growing worse. Here is a thorough guide on what problem signs the average homeowner can look out for, what causes these ventilation issues in the first place, and how the crawl space experts at Tar Heel Basement Systems can help.   

open crawl space vents

Causes Behind Crawl Space Ventilation Issues   

Being able to identify key problem signs before they grow worse can be immensely helpful to prevent them from growing worse. However, problem signs typically arise after the damage has already been done. It may be even more useful for homeowners to know what is causing all this damage in the first place. Here are a few of the most common causes behind crawl space ventilation issues below.    

  • Open Crawl Space Vents   

If the problem lies with improper ventilation, you might think that opening up the crawl space will help circulate air around to keep it nice and dry. Most builders also had this same thought. In fact, many building codes today still require all crawl spaces to have these open vents in order to adhere to these out-of-date ideas. Open versus closed crawl space vents are still a hotly contested debate among contractors even to this day.  

The belief that open crawl space vents could circulate dry air began approximately in the 1950s when many building codes implemented this practice in homes all over the country. Since then, it has become a widespread belief that these open vents are a natural part of building the crawl space. This is simply incorrect.   

In the 1990s, the stack effect was thoroughly studied and found to affect open crawl space vents no matter the weather or climate. This has paved the way for professionals to start closing up the crawl space vents despite building codes still requiring they be added outside the crawl space. Because national building codes are slow to change due to these debates, some will still stand by open vent installation despite all its flaws.  

Open crawl space vents actually invite more moisture, mold and mildew spores, pests, and other issues inside. It is best to close these vents to prevent this from happening.  

In winter, there is a high likelihood that the systems within the crawl space will freeze or be piled with snow. This is why they will suggest blocking the vents or closing them altogether. However in the summer, you also have to deal with plenty of humidity, mold and mildew spores, or pests infiltrating through the open vents, too. So, there really is no benefit to open vents whatsoever.  

  • The Stack Effect    

Humidity can be a huge issue within the crawl space. North Carolina often faces humid summers, which only makes any existing humidity within the crawl space that much worse. Hot air tends to rise and circulate all throughout your home. This can be unbearable in the already humid summer, so you might find yourself turning your air conditioner even higher to stay cool.   

Of course, the cold winters can also pose their own set of problems, too. The cooler outside air could collect within the crawl space and push out the warm air inside your house. This results in you having to turn your heat up even higher just to combat this strange draft. Either way, the stack effect will cause your energy bills to rise considerably just so you can stay comfortable.   

Common Crawl Space Ventilation Problem Signs   

Improper crawl space ventilation can cause all sorts of issues no homeowner wants to deal with. Here are just some of the most common problem signs crawl space ventilation can create within your home.    

  • Leaks or Flooding   

The first place you might notice any problems within the crawl space may not actually be in the crawl space itself. Rather, you may first notice issues arise in other areas of your home. This is because the crawl space is located between the ground and first floor of your house.   

This includes any leaks that may spring within these areas. It is possible the leaks could pour through any open cracks. They may also be a sign that your crawl space itself is flooded, and all that standing water has nowhere else to drain.   

You might smell the standing water before you notice it trickling into your home. The crawl space can become quite humid due to the insulation packed within. The longer you leave this water alone, the mustier the stench inside may become. It is even possible that sewage may have leaked out into your crawl space as well.   

You definitely do not want any of that flooding your home. It’s important to call a crawl space expert as soon as you can. The experts at Tar Heel Basement Systems are well versed in crawl space and other issues, so you can count on us to fix the problems you find in these areas.   

  • Cracks    

Damage found within the crawl space can work its way down to your home’s infrastructure as well. If you see any cracks starting to form along your floor or up the walls, then it could indicate hidden damage within the crawl space too.   

Cracks can pose a serious threat, spreading out to cause more damage to other parts of your home. 

Hairline cracks that measure less than 1/8 of an inch wide will not pose any immediate threat to your home. However, you should still try to schedule a crawl space inspection with Tar Heel Basement Systems as soon as you can. These smaller cracks can easily spread out to cause damage to other parts of your home at any time.   

Cracks that are wider than 1/4 inches wide or wider need to be addressed right away, especially if they span both your walls and floor. These cracks often signal significant damage just below your feet. These larger cracks may even be signs that your very foundation is cracked as well.    

  • Mold and Mildew Growth   

Constant flooding or leaks can be more than an annoyance or hassle to drain out. This collective moisture can also entice mold or mildew spores to settle and grow within your crawl space and/or throughout your home. Mold and mildew will grow on most organic materials, including the wooden beams used to support your home, wallpaper, cardboard, ceiling tiles, and even within your pipes.   

Mold tends to be black or green in color, and slimy or even fuzzy in texture. Mildew, on the other hand, is a chalky white or gray color and is powdery or fluffy in texture. Mildew will also turn brown or black over time, which means it can be mistaken for mold.   

Mold and mildew are not necessarily toxic fungi, but they can induce negative health effects in you and your family. The Centers for Disease Control and Prevention states that mold can cause watery or burning eyes, stuffy nose, sore throat, and coughing or wheezing. These are just the symptoms that can occur in otherwise healthy homeowners. Homeowners that suffer from asthma or chronic lung disease may find their own existing symptoms exacerbated or infections rooting inside their lungs.   

Mold and mildew can also emit a strange, musty odor as well. If you notice any odd smells that seem to hang around, then it is a good idea to have your home inspected by an expert to determine the true cause before it can grow worse.   

  • Pest Infestations    

Where floods and cracks sprout up, pest infestations are sure to follow. Pests of all kinds tend to be more drawn to homes that have moisture issues. Any cracks along your walls or floor may also provide an easy entrance for any pests to crawl into. These pests can then squeeze through and infest the rest of your home. Once pests infiltrate your home, it can be very difficult to drive them out again.   

Some pests may even emit a musty scent that will attract other pests to your home. You will know if the infestation has gotten out of hand if you see any pests scuttling around your floors in broad daylight. It is possible that the infestation has become so overcrowded that these extraneous pests are then forced to scavenge for food elsewhere.    

  • Uneven Floors   

Moisture buildup can also warp wooden floor beams over time. The excessive moisture can also entice mold or mildew to cause the support beams to rot away. As a result, some parts of your floor may begin to sag in the process.   

The wooden beams may also start to sink or dip on their own if the columns or piers are constructed over weaker supporting soils. Either way, if you find that your floor tends to dip in certain places, it is very likely that the support beams underneath have started to rot away. This uneven floor can pose a dangerous tripping hazard to you and your family.   

Often, the wooden support beams are located within the crawl space. If you notice problems with uneven, sagging floors, it is a good idea to call the crawl space experts as soon as you can. They can help ensure your home does not sink into the soil.   

The Best Crawl Space Solutions   

Our crawl space experts can implement a process that will completely encapsulate your crawl space. It consists of the toughest solutions that will work in tandem to protect your crawl space from moisture issues, mold, pests, and other problems the crawl space is likely to face. 

This process consists of interior drainage and sump pump installation followed by insulation, vapor barrier, and vent cover protection. Finally, we will install a dehumidifier inside the crawl space to ensure that it will remain completely dry no matter what.  

Crawl Space Ventilation


Maintaining the crawl space is vital to your home’s overall health. The systems and structures found inside are too crucial not to at least take measures to protect them. Let’s go over why the crawl space is so important to your home.  

  • Contains Vital Systems and Structures   

As its name implies, the crawl space tends to be just big enough for the average adult to crawl around in. Ceilings for these spaces can range anywhere between one to three feet high. Of course, even a larger crawl space can become cramped and difficult to navigate with all the vital systems scattered about.  

The crawl space’s main function is to store all your home’s important systems within it. This includes your plumbing, electrical wiring, HVAC system, insulation, and foundation. None of these systems should have any moisture even touching them, much less be submerged in a large flood of water. Moisture can wreck these systems, causing substantial damage not only to your crawl space but your entire home as well.  

  • The Foundation   

The foundation is an especially important structure for your home. It keeps the entire house standing steady and upright. Because many foundations nowadays tend to be made of concrete, you might think that there is no way that your own foundation could break apart.  

Unfortunately, moisture can easily shift or even crack your foundation from within. A damaged foundation can prove to be devastating for the rest of your home. You might find your doors or windowsills sticking or even your very walls starting to tilt. It can be extremely costly to repair these damages, so you need to ensure that your crawl space is protected to prevent this from happening in the first place.  

The crawl space is difficult for most people to access. You can risk accidentally damaging something important or even getting yourself stuck in this tight space. To make things easier on yourself, and ensure you get professional results, it’s helpful to leave any repairs to the crawl space experts at Tar Heel Basement Systems instead.  

  • Why DIY Repairs are Not Enough   

The average homeowner won’t have access to the right tools or experience to repair elements within the crawl space. Indeed, it is a cramped fit that does not offer much wiggle room, which leaves homeowners to struggle in the uncomfortable area. You might even find yourself stuck in this cramped space, or accidentally bump something that isn’t designed to be jarred.   

DIY solutions that home improvement stores sell tend to wear away over time. Buying the same solution to fix the same issues repeatedly soon develops into an unnecessary expense. That’s why it’s helpful to invest in more professional, permanent waterproofing solutions that work to protect your crawl space no matter what.  

  • Trust the Crawl Space Experts   

The crawl space experts at Tar Heel Basement Systems have all the right tools and know-how for any tough crawl space repair job. Our experts can navigate through these tiny spaces without disrupting any of the essential systems or structures within. We can also install powerful solutions that will work to permanently waterproof your home.  

Your crawl space is too important a space to neglect. That is why hiring the crawl space experts to inspect this space every year can be a huge help. If any problems do arise, we can quickly implement the best solutions to repair them before they become any worse.  

Crawl space encapsulation will permanently protect your home from any and all moisture. Each part works together with the others in this system to ensure a complete waterproofing experience.   

  • Sump Pumps and Dehumidifiers    

Oftentimes, installing an interior drainage system and a sump pump is the first step to the encapsulation process. If your crawl space is flooded, our experts cannot work on waterproofing this space until that water is all drained away. Our drainage system and sump pumps require very little maintenance, but it’s still important to have these systems checked by professionals on a yearly basis to make sure they continue to work in keeping your crawl space dry.   

Installing a dehumidifier is actually the last step to the encapsulation process. It is often added as a precautionary measure should any moisture still remain. These industry-grade dehumidifiers are much more powerful than the ones you might find at a department store. You can rest assured that these machines will protect your crawl space against any lingering humidity or other irritants floating about to create a cleaner, drier crawl space environment.   

  • Vent Covers, Insulation, and Vapor Barriers    

If open crawl space ventilation only worsens existing issues, it makes sense to cover them up from the outside elements. After draining all the standing water from your crawl space, Tar Heel Basement Systems can then install our sturdy vent covers directly over the open vents themselves. This ensures that no outside moisture or mold will be able to sneak their way into the crawl space or the rest of your home. No encapsulation process is complete without sealing off any open crawl space vents, which makes these covers all the more necessary for your home.   

We’ll then place durable insulation panels on the walls and cover the crawl space walls and floor with a 20-mil vapor barrier that will not tear under any duress or pressure. The two particular solutions help seal your crawl space from outside nuisances like unconditioned air and moisture, and they make it more difficult for pests to get inside. Additionally, our insulation panels are treated to resist termites, and the vapor barrier is treated with an antimicrobial to resist water and mold. Both these solutions also are installed with a three-inch gap allowing for pest control inspections.

Contact the Crawl Space Experts for a Free Inspection Today   

The crawl space is perhaps the most important place in your home. Unfortunately, this area doesn’t always get the attention it needs. Preventing issues within your crawl space starts with being able to recognize smaller crawl space ventilation problem signs and calling the crawl space experts to repair them before it becomes too late. Contact the crawl space experts at Tar Heel Basement Systems to repair your crawl space issues today. We can provide you with a free crawl space inspection and repair quote on all our crawl space solutions. We serve all throughout the Raleigh and Winston-Salem areas.

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3400 Walsh Pky, Suite 220
Fayetteville, NC 28311

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611 Summit Ave, Suite 5
Greensboro, NC 27405

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Raleigh, NC 27609

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3333 Air Park Road
Fuquay-Varina, NC 27526

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1209 Culbreth Dr., Ste 205
Wilmington, NC 28405

Winston-salem / High Point Location

2910 Griffith Rd
Winston-Salem, NC 27103