Why Is There Always Water in My Crawl Space?

The presence of water at any time in your St. Louis, MO, crawl space has the potential to cause damage, but persistent dampness and water pools in your crawl space are a sign of ongoing and serious issues in your home. 

Seepage, Groundwater, and Open Vents 

If your crawl space is persistently damp and commonly has pooling or standing water in it, there is a good chance that it is in some way vulnerable or exposed and that this is the source of the water (rather than damage of some kind). The most likely sources of moisture that are not connected to damage of some kind are an exposed crawl space floor, a process known as seepage, and open crawl space vents. 

Seepage and the saturation of a dirt floor in a crawl space are processes that hinge largely on the porous nature of concrete. When the soil around and under your home is saturated, the concrete foundation and foundation walls may start to absorb water, slowly letting it pass through them and into your property. This will cause minor dampness at first but can lead to significant amounts of water over time. Open crawl space vents, by contrast, can let water pass directly during periods of intense rainfall, heavy snowmelt, or localized flooding. Likewise, they can cause increased humidity and condensation as a result of the impact of the stack effect. 

Internal and Structural Damage 

If the amount of water in your home is significant, it is more likely that the underlying source is some form of damage to your property’s structure or plumbing system. A crack, leak, or rupture somewhere in a property’s plumbing system will be the most obvious and serious source of water—a full-size plumbing flood can cause copious amounts of water to enter a crawl space in a very short period of time. It is far more likely that a low-level leak will be to blame for small amounts of standing water or persistently high humidity. 

Structural damage like cracking and fragmentation in a property’s foundation or foundation walls can also be responsible for small amounts of water and high humidity in a home. This generally happens because of water’s incredible ability to find even the smallest channel in which to travel. Even a hairline crack can allow water in your home and, over time, the passage of water through small cracks can contribute to their growth and spread.