Why Is There Standing Water in My Crawl Space If It’s Unventilated?

It was once believed that crawl spaces need to be ventilated in order to help with air circulation and ward off humidity. However, we now understand that ventilating a crawl space does nothing more than bring in moisture, water, and insects. To avoid crawl space flooding, what many homeowners do is simply install a crawl space vent and call it a day. While crawl space vent covers do help, there’s still a chance for you to find standing water in your crawl space. Unless the space is fully waterproof and well-insulated, condensation will create moisture.

Condensation is the opposite of evaporation. Water turns to vapor when the temperature is hot enough, but, when it’s cold, water vapor can turn into moisture. This is known as the dew point, which is the temperature the air needs to be in order to reach a relative humidity of 100%. Essentially, there is so much moisture in the space that the air can no longer hold it all, so it gets released onto surfaces as water droplets.

If your Rochester home’s crawl space is poorly insulated, then it means that the air from outside is capable of infiltrating the space and creating the right temperature to cause condensation. The water droplets that form on your floor joists, HVAC systems, and pipes eventually drip down and cause the standing water that you see. The best way to avoid condensation is to encapsulate your crawl space with a vapor barrier so that moisture cannot get in. If moisture somehow makes its way in and you have a crawl space dehumidifier, then you won’t need to worry about the humidity for long. A good insulation material can also trap air so that the temperature in the crawl space doesn’t change.