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Open Crawl Space Vents

Because of moisture, mold growth, and flooring system failures, professionals are discouraging open crawl space vents these days. Here's why.

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Crawl space vents are commonly behind numerous problems and affect the comfort and overall quality of your home. Read on as we demystify whether you should keep them open or not.

crawl space open vent

The Basics: What Are Crawl Space Vents?

Crawl space vents are located on foundation walls. Building codes across the country require homes with below-grade levels to have them. As such, if you have a crawl space area, you likely have vents too. 

These fixtures have only one purpose and that is ventilation. Common sense tells us that every closed space should have a vent that enables necessary airflow. However, the opposite is actually true.

Keeping them open constantly will mean moisture-related problems in your lower-grade level. In addition, crawl space vents can also cause the stack effect. The reason for these issues is the fact that keeping your vents open means that there will be constant air movement from the bottom to the top of your home. But since crawl spaces aren’t the cleanest of areas, the flow of air will spread mold spores, dust particles, and allergens all over your living spaces.

Should I Keep My Crawl Space Vents Open or Not?

The original purpose of these fixtures was to allow for constant air movement under a structure that has a crawl space. Back then, when crawl space vents were invented, it was thought that they would prevent moisture from building up by enabling the flow of air in the crawl space. However, it turned out that the free flow of air in crawl spaces actually encourages the growth of mold, mildew, and wood rot.

Open crawl space vents can cause pipes to burst in the winter as it is much more difficult to keep the temperature in them above freezing. When you leave them open, the temperature can drop so low that even the best of pipes won’t make it through the whole season without damage. 

Common Problems with Keeping Your Vents Open

Here are some issues you might face if you leave your crawl space vents open.

Brings in moisture: The first and most obvious problem is that an open crawl space will bring moisture into your home. It allows humid air to freely enter your crawl space and affect humidity levels. Very high levels of humidity can compromise the structural safety of your home.

Encourages pests: Like us, critters also look to keep themselves warm in the winter. If you leave your crawl space vents open, these animals can find their way into your home. Did you know that a mouse only needs a quarter of an inch of space to squeeze through? Keep in mind that mice aren’t the only animals looking to keep warm when outside temperatures drop.

Inefficient energy use: The free flow of outside air in your crawl space will make it difficult to keep the temperature inside optimal. This means that you will use more energy to keep cool in the summer and warm in the winter as your crawl space will be working against you.

Affects air quality: Finally, if you leave your vents open, the quality of the air in your home will drop significantly. As a result of the stack effect, dust, mold spores, allergens, and numerous other pollutants will endanger your health and that of your family by moving up from the crawl space into your living areas. It might start with a runny nose, but that won’t be the end of it.

How to Seal Crawl Space Vents

One of the best things you can do for your home right now is to seal your crawl space vents with durable and airtight vent covers. This will allow you to keep your home nice and dry and ensure its structural safety by avoiding mold problems and more. 

Crawl Space Encapsulation

Although sealing your crawl space vents will go a long way, to eradicate your moisture problems, it’s best to encapsulate your crawl space. If you’re looking to do so, contact FSM to schedule a free inspection and repair estimate right now. Our professional team serves the Detroit area, Grand Rapids, Traverse City, and surrounding areas in Michigan. Make sure your crawl space is safe and secure for years to come.

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