Crawl Space Vents

One thing many crawl spaces still have is open vents. These vents allow outside air and water into the crawl space. Can you keep your crawl space vents with an enclosed crawl space, or do you have to remove them? What do they do? Is it important to close or keep them?

These are the most important things to know about crawl space vents. 

Common Practice for Many Years

The main reason you find so many crawl spaces with vents is that it was just common practice for many years to do it. The prevailing wisdom for a long time was that crawl spaces “needed to breathe,” and that’s why crawl space vents became so popular.

Especially if your home is fairly old, it’s possible that you have crawl space vents even if you don’t know about them. At the very least, you should know whether or not you have crawl space vents in your home.

Understanding whether you have crawl space vents is an important first step when you’re trying to figure out how to handle crawl space encapsulation. Encapsulation requires that you seal all open crawl space vents

New Research Shows Crawl Space Vents Don’t Work

If crawl space vents were such a common practice for so long, why are they not in use as much anymore? The short answer is, the assumption regarding crawl spaces needing to “breathe” was based on poor reasoning.

Essentially, crawl space vents let in more moisture than they keep out. They allow in cool air from outside, humid air from outside, and water from rain and flooding.

Nowadays, it has been well established that crawl space vents just don’t work to keep crawl space moisture low. In fact, the opposite is true. That’s exactly why many contractors are helping people seal them up.

Because of the stack effect – the movement of air through your home from bottom to top – whatever is in your crawl space also is in the air in the rest of your home and affecting you. With a home that has a dirt crawl space and open crawl space vents, moist air that is vented inside will rise through the house and then get recycled once it reaches the attic or roof. This, in turn, can lead to mold, mildew, and wood rot. Since your air recycles and moves up and down through your home, you and your family are breathing it all in. These are huge health risks! 

Sealing Your Crawl Space Is the Best Option

Proper crawl space encapsulation requires that you seal your crawl space entirely. That includes removing or sealing shut your crawl space vents.

It can be tempting to buy into the logic that crawl space vents allow air to move more effectively throughout the crawl space, therefore drying it out. However, time and time again, contractors have seen that a closed crawl space does that much more effectively.

JES contractors know that crawl space encapsulation requires that you don’t have open crawl space vents. Talk to a JES expert today to learn more about your options if you do have crawl space vents.

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