Learn why venting your crawl space is bad for your home

Crawl space vents are a major problem for your home. During the summer months, the moisture and humidity levels are already running high. By leaving your crawl space vented, air (including humid air) can easily move into your crawl space. Air brings moisture content with it wherever, which can result in humid air entering and festering within your crawl space.

Soil temperatures remain around 55 degrees Fahrenheit year-round, leaving crawl spaces relatively cool. When warm, humid air comes through the crawl space, that air is cooled and the relative humidity increases. High relative humidity is known to cause problems like rot, mold, energy loss, and can serve as a breeding ground for critter infestation!

What is “relative humidity”? This is how full of water the air is relative to the maximum amount of water it can hold at a given temperature. So, if on a hot summer day, you have hot outside air mixed with 70% relative humidity entering your crawl space vents, the air in your crawl space is 70% full of water. So, if groundwater seepage and moisture-filled air are causing your crawl space’s relative humidity to climb to 60, 70, 75%+ relative humidity, you may soon have a serious issue on your hands.

Despite feeling humid or featuring pervasive, musty smells, humid crawl spaces will start to exhibit condensation, which can result in wet foundation walls, sagging, dilapidated floor joists and girders, and heavy, droopy insulation...which rodents, insects and snakes just love!

What’s worse, is that warm air rises due to what’s called “the stack effect”. The stack effect creates airflow in your home from bottom to top. We’ve established that crawl spaces remain relatively cool, so guess where that cooler air rises? Yep! Through your home! So like it or not, you ultimately end up breathing in that damp, nasty crawl space air! will eventually exit upwards...through your house itself. So, you actually BREATHE that nasty air!

There is also direct correlation between the relative humidity and wood moisture content in a home. When wood is in a damp environment, that wood can also become damp, like firewood left out in a heavy rainstorm. Damp wood rots, can grow mold, and over time, will lose its structural integrity, often serving as a catalyst for soft or sinking floors above. Anything above 55% relative humidity can start to deteriorate organic substances (ie, the “roof” of your crawl space...the wooden floor joists supporting your home’s floors above), so if your crawl space is experiencing high relative humidity, chances are, your home may suffer structurally over time.

Do you have concerns about your crawl space during these hot summer months? If so, Liberty Basement Systems is your local trusted experts. We repair nasty crawl spaces all the time, and we’re here to help! Don’t let YOUR crawl space issues fester. Call our office today and schedule a free in-home evaluation.