What Causes High Indoor Humidity?

There are many potential reasons for high indoor humidity, and most of them come from your crawl space. Here are some of the biggest reasons you might have high indoor humidity. 

Open Crawl Space Vents 

For a long time, people believed that crawl space vents needed to stay open. In fact, it was a common belief that a vented crawl space was necessary to avoid moisture in the crawl space. The idea was that a vent would “air out” the crawl space, thus making it less likely to succumb to high moisture and other problems. 

However, it’s actually true that open crawl space vents increase the amount of moisture in the crawl space, rather than decreasing it. Open crawl space vents allow cool air and warm air to meet, which increases the relative humidity in that area, typically above 100%. Once the humidity goes above 100%, it turns into water, typically in the form of condensation on cool surfaces. 

Dirt Crawl Space  

Dirt crawl spaces are cheaper and easier to manufacture, which means they’re a popular option for many designers and manufacturers looking to save money. However, while they might be cheaper and easier for the initial building team, they’re much more frustrating to deal with as a homeowner because they’re prone to high levels of humidity. 

When you have a dirt crawl space, you’re not really going to be able to fix your humidity problems unless you lay down a durable water vapor barrier. That’s because even if you dry out the top level of the dirt, the earth will still be moist far down, which can rise into the crawl space and cause plenty of issues with high humidity. 

Lots of Rain  

Have you recently had issues with rain in your area? If you have, it could be impacting your home’s ability to avoid leaks and water coming into your crawl space. Rain can increase the amount of hydrostatic pressure on your home’s foundation as it sinks into the ground, which can be difficult on your crawl space walls. 

Unfortunately, rain issues are common in many areas of the United States’ East Coast. The closer you live to the coastline, the more likely you are to have serious problems with rain. You need to be prepared for the ways in which rain problems can impact your home’s stability, and excess crawl space moisture is one of the ways it can do so. 

Flooding in the Area 

Rain can sometimes cause flooding, which can end up causing its own problems. Not only can floods sink into the ground, where they cause large amounts of hydrostatic pressure, but they can also cause large amounts of water to stand around a home. This can be terrible news if you have crawl space vents or windows that are ground level. 

Although flooding is a different problem than rainwater, it often comes along at the same time. This is especially the case if your area tends to have a “dry season” and then a “wet season.” The dry season will dry out the soil, making it less open to rainwater soaking into the ground, and the wet season will be more likely to cause floods.