Case Closed: Keep Your Crawl Space Vents Closed!

What’s outside in the Summer and Spring? Insects and humidity.
What’s outside in the Fall and Winter? Frigid air.
Opening crawl space vents is bad news during ANY season. It allows for not only all of the things previously mentioned to make their way into your crawl space, but also allows MOISTURE to creep in. Moisture can cause an array of issues in your crawl space, such as causing mold, mildew, dust mites, and wood rot. Three of the four are common indoor allergens that can cause sneezing, itchy eyes, and even asthma! And wood rot is exponentially bad for your home’s foundation. You see, moisture rises when it evaporates in your crawl space, and when this happens, the moisture does frightening things like go through the insulation, walls, and floors of your home, which can ruin your home. 

The building code allows dirt crawl spaces that are vented. In fact, it requires them to be vented! And many boards insist on ventilation, as well. If there is mold or rot, their solution is to add even more vents, and guess what? That has never worked! There is no evidence that supports ventilation and now that new research is out it is time for a change!

Let’s say that your vents are open in the Summer and the warm, humid air comes in. For one, it’s increasing your relative humidity, which can cause mold to grow on your wood supporting beams. And because the way the air pressure changes, it pulls air from the lowest point (aka your crawl space). So, now 50% of the warm air that has been exposed to mold and everything else in your crawl space makes it to your home’s first floor.

Open vents aren’t only bad for your home’s health, but it can also be bad for you and your family’s health. Keeping your vents open during any season will cause unwanted elements inside your home. Elements that can ultimately affect you and your home’s health. Not to mention, your HVAC system has to work much harder to keep your indoor temperature the way you like it, while the open vent is inviting the outside air in.

To sum it up, there is no supporting evidence that proves open vents help eliminate mold or rot. Moisture is being brought in and CREATING this mold and rot. Close your vents and seal them up for good, your wallet and home will thank you. Case Closed!