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Why and How to Seal Your Crawl Space Vents: Problems, How-To Steps, and Benefits

crawl space vent

Many homes in North Carolina feature crawl spaces that store HVAC units, pipes, ductwork, and wiring. When crawl space vents are open, these areas are susceptible to moisture and outdoor elements, potentially leading to concerns such as mold growth and structural issues. To address this risk, consider improving your crawl space ventilation.  
Managing moisture infiltration in crawl spaces is a common challenge for homeowners. If you’re determining whether to leave crawl space vents open or closed or learning how to seal them, you’re in the right place.  

This page explores crawl space repair, the risks of open crawl space vents, and how to seal them for optimal protection. 

The Myth of Crawl Space Vents: “Open in Summer, Close in Winter?”

Up until the mid-20th century, building standards advocated for the installation of vents in crawl spaces to improve air circulation and control moisture. The reasoning went like this: If moisture is getting into your crawl space, it needs a way out again. So, the obvious solution to this is to just add vents that homeowners can open in the summer and close in the winter.

However, this is actually a myth that has been debunked.

Opening Your Crawl Space Vents Doesn’t Work Because…

Studies in the 1990s showed that these vents often introduce moisture, reducing energy efficiency and making temperature regulation inside the home more difficult. 

Here are all the problems we’ve seen that are often caused or made worse by open crawl space vents.

As a result of all of this, the trend of using crawl space vents has declined, and building codes have evolved to favor vent sealing and encapsulation techniques. 

That’s why we recommend closing and sealing crawl space vents to improve the overall condition of your home. It’s a proactive step you can take in safeguarding your investment. 

How to Seal Open Crawl Space Vents 

So, the question is, “How do I seal my crawl space vents?”

At Tar Heel Basement Systems, our process for addressing open crawl space vents goes like this: 

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Choosing Tar Heel Basement Systems means opting for a solution that utilizes proprietary products designed for durability and effectiveness. 

Top 5 Benefits of Sealing Open Crawl Space Vents 

Taking immediate action to address open crawl space vents is essential for maintaining the integrity and value of your home. The reasons for this urgency include: 

  • Preventing Structural Damage
  • Enhancing Indoor Air Quality
  • Boosting Energy Efficiency
  • Deterring Pests
  • Enhancing Property Value

To give you the full benefit of an encapsulated crawl space, Tar Heel Basement Systems offers a unique combination of expert knowledge and high-quality products, leading to unparalleled results in addressing open crawl space vents. Our solutions go beyond mere quick fixes, offering long-term benefits that protect and enhance your home on multiple fronts. 

Want to Seal Your Crawl Space Vents for Good? Call Tar Heel! 

Tar Heel work truck

If you live in North Carolina and see issues around your home that could be due to open crawl space vents, schedule a free crawl space inspection with Tar Heel Basement Systems today.

Our team provides tailored crawl space repair and encapsulation solutions to address your home’s needs. We have decades of experience ensuring peace of mind and a healthier home environment. 

Wondering if we serve areas near you? Check our Service Areas page!

Let our Crawl Space Experts help you

Schedule free inspection
Schedule free inspection
Production crew installing ventilation.


When the process of sealing a crawl space is done incorrectly, it can lead to moisture issues, resulting in mold and other unhealthy issues. Professional installation ensures adequate ventilation and prevents potential problems.

Waterproofing crawl space vents involves specialized sealants to create a moisture-resistant barrier. Contact a professional who can inspect the area and offer tailored solutions for your home’s space.

Yes, sealing a crawl space is a beneficial step to prevent moisture, pests, and insect intrusion, improving your home’s living conditions. It’s crucial to contact a professional and address open crawl space vents to ensure proper ventilation and avoid potential moisture issues.


Michael Wilcher

Michael Wilcher

Michael Wilcher is the Content Lead at Groundworks, helping us to answer all of our customers biggest questions about foundation repair, basement waterproofing, crawl space encapsulation, and concrete lifting. In his free time, Michael enjoys collecting vinyl records, watching Formula 1 Racing, and reading philosophy. He holds an MPhil from the University of Cambridge.

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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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Leland, NC 28451

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