What Causes Crawl Space Condensation?

Condensation is caused by excessive relative humidity and the difference in temperature between the air and certain surfaces. This is why glass and metal surfaces are more likely to show condensation, even in a relatively arid environment. 

Uncovered Vents 

If your property has an unencapsulated crawl space with uncovered vents, this is the most likely cause of condensation. Crawl space vents were originally installed into properties because they were believed to increase airflow and prevent dampness and humidity. This has since been shown to be a false assumption. In fact, the truth is quite the opposite; crawl space vents are far more likely to increase dampness in your home. 

This is partly because of the way that uncovered vents leave your crawl space open to the weather (which can lead to flooding in serious cases). Uncovered crawl space vents can increase humidity in your home even when the weather is mild. They do this by allowing warm, humid air to circulate in your crawl space. When this warm, humid air comes into contact with cool surfaces in the crawl space, condensation will form. 

Structural Damage 

If your crawl space vents are covered, or you do not have crawl space vents, the most likely source of humidity, moisture, and condensation in your crawl space is either seepage or some form of structural damage. Seepage is the process by which water seeps through porous concrete when exposed to extreme saturation. Damage is more varied. Cracks in your property’s foundation or crawl space walls, for example, can let water seep into your crawl space from the ground around your property. This damage can be caused in a number of ways, from excessive hydrostatic pressure to loose, weak, or expansive soil causing movement and cracks in your property’s foundation. Finally, damage to plumbing and appliances in your home could cause humidity to increase sufficiently to cause condensation.