What Is a Wet Crawlspace and How Can You Fix It?

Tips from a Crawlspace Industry Expert

Most traditional crawlspaces are wet to some extent because of the way Mother Nature works. Let me take you back to our middle school days, where we learned about the Earth and how the weather cycles impact our planet.

Remember the experiment the teacher did to demonstrate how moisture evaporates into the air and rises into the clouds, where it cools and condenses and then returns to Earth as rain? My teacher placed a glass jar upside down on the ground and in a short time, the inside of the glass jar collected moisture droplets and eventually water would run down the sides of the jar back into the ground. That’s science, and there’s no way around it.

Another visual example is when you lay something on the ground, such as a cardboard box or a plastic tarp or even a piece of wooden board, and after a while, lift it up and with very few exceptions, you will find moisture on the side facing the ground. This is because of ground evaporation.

Accounting for Evaporation

Evaporation happens every day on our planet. The sun’s rays heat the ground, and the air at ground level is warmed. As the ground is heated, moisture in the ground turns to water vapor (moisture-laden gas). As the heated air rises, it is lighter than cold air, and the gas, which is also lighter, rises with it. This moisture-infused warm air will continue to rise until it comes in contact with a surface or an altitude that is colder. The difference in the temperature is called the dew point.

This natural cycle, over time and in addition to the many other conducive conditions such as poor outside or inside drainage, lack of or too much foundation ventilation, and many other factors, will determine the degree of moisture in a crawlspace at any given time. Therefore, when you measure the moisture content of the wood and it is over 20%, you have what is called a wet crawlspace.

Of course, you can determine there’s an issue even without measuring the moisture content of the wood. if you see standing water inside a crawlspace, fungal growth, or mildew and mold on the wood or foundation walls, chances are high that the crawlspace is wet. And in some instances, you can actually smell a musty odor when you open the crawlspace door.

What’s Wrong with Wet Crawlspaces?

Wet crawlspaces are a real threat to the structure and the homeowner. In my experience and professional opinion, when you find a wet crawlspace, it is going to take the expertise of a professional to correct the problem.

Wet crawlspaces can be inviting environments for termites, carpenter ants, rats and mice, and even feral animals like snakes. Wet crawlspace environments can also be a safety concern for people working in the space, ranging from threats like electrical shock to fires from electrical short circuits.

How Can You Fix a Wet Crawlspace?

There is some good news though. Wet crawlspace situations can be reversed. The damage will have to be addressed if it is structural, but if it is not structural, eliminating the conducive conditions and controlling the moisture in the crawlspace can make the space a more effective and efficient part of the structure.

Wet crawlspace conditions can be remedied and controlled with modifications to the inside of the crawlspace and, if necessary, outside the crawlspace. If there is a foundation drainage issue allowing outside water intrusion into the crawlspace, a foundation drain system and sump pump may be necessary. If the wet condition is from ground evaporation and high humidity, closing the foundation vent openings and installing a complete moisture barrier with a dehumidifier should dry the crawlspace and keep it a controlled environment.

You can learn more about wet crawlspaces and the threat they pose to structures and the homeowner by visiting the Your Crawlspace website. The professional team at Your Crawlspace will be more than happy to help you and your team with understanding how to identify and correct wet crawlspaces. Your Crawlspace offers training, patented products, and a crawlspace encapsulation system that is tried and proven to support you in developing a successful service offering.

Don Richards, ACE, CPI