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The Ideal Crawl Space Humidity Level

What should the moisture level be in your crawl space? A surprising number of homeowners don’t know the answer to this simple question. If you don’t know the ideal crawl space humidity level, how can you combat an unhealthy one?

The first step is learning the ideal humidity level for your crawl space. Here’s what you need to know. 

Knowing the Perfect Level

The right crawl space humidity level is an important factor to know when you’re trying to maintain your home’s crawl space integrity. As a general rule, you should typically keep your crawl space humidity level under 55%.

This level may change a little bit depending on where you live and the season you’re in. However, it’s a good idea to measure this humidity level year-round. You may need to do specific things to maintain your crawl space humidity in different seasons.

A hygrometer, which measures relative humidity, is a great tool for this. However, many people don’t have this tool and don’t know how to maintain this humidity level. A JES expert can help you understand the hygrometer reading and get a better understanding of your home’s humidity. 

Relative Humidity

It’s important to understand a little bit about relative humidity when you’re trying to understand crawl space humidity. Relative humidity measures how saturated the air is — at 100%, you get rain or thick condensation, because the air is too saturated to hold all the moisture inside it.

This is also an important concept to understand because it changes based on the temperature. Warm air can hold more water vapor than cool air, so the same amount of water vapor will result in higher relative humidity in cooler weather.

The relative humidity is the important measurement in a crawl space. Even if you don’t think there’s any reason for a high relative humidity measurement, it’s important to book a free inspection with JES to make sure everything is going well.

Low Crawl Space Humidity 

What if you have a very low level of humidity in your crawl space? Can crawl space humidity be too low? Technically, you can overdry a crawl space. If the crawl space moisture drops extremely low, you can dry out the wood, causing structural damage.

The good news is, it’s not really feasible for you to lower crawl space moisture that low. However, if you live in an extremely dry area, you may find that a dehumidifier for a crawl space drops the humidity lower than 30%, which is typically where humans start to feel uncomfortable. That can expand into the rest of your home as well.

It’s a good idea to keep your crawl space moisture between 30%-50% for maximum efficacy. A good dehumidifier can help you keep your crawl space dry when necessary, but make sure it maintains a healthy level of moisture. Talk to a JES expert if you’re worried about lowering the crawl space humidity too much. 

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