When moist air enters a vented crawl space, condensation occurs on cool crawl space surfaces.

Crawl spaces are particularly susceptible to moisture and humidity. Based on the structure of your crawl space, it can trap humid air and lead to condensation build up without proper air circulation. This condensation can eventually lead to serious moisture issues in the long run.

Most of the problems traditionally associated with damaged, rotting crawl spaces are due to basic flaws in the ways that crawl spaces were designed. Their tight space doesn’t allow for much air circulation to enter, leaving your crawl space with moisture buildup.

If you’d like an expert opinion on the humidity levels in your crawl space, we offer free crawl space repair inspections in all of central Missouri and Eastern Kansas, including Kansas City, St. Louis, Columbia, Moberly, and Springfield. Call or email us today!


How does humidity enter a crawl space? If the air outside is wet or humid, then your crawl space vents are bringing in moisture. Crawl space humidity leads to all of the following problems in your home:

Wood that stays damp in a dark crawl space is an ideal mold habitat. Eventually, mold causes wood decay that can destroy structural parts of the house.
  • Rotting & mold
  • Rusted, corroded metal
  • Odors & allergens
  • Higher utility bills

Humidity has a number of damaging effects on your crawl space. The buildup of humidity creates a perfect environment for mold to grow, which can cause health-hazardous impacts on you and your family. It can also ruin any wooden floorboards or support beams in your crawl space.

Not only does it impact your crawl space but can also lead to other unwanted issues inside your home. The moisture buildup can cause the floor joists to become weak, resulting in sagging floors inside your home.

Additionally, many pests (termites, carpenter ants, wood-eating beetles, crickets, etc.) love rotting, moldy wood. Your moisture and the issues it brings will be an invitation for them to move in.

During the hot summer months, crawl space humidity will also increase your home’s cooling bills. Have you ever seen water dripping from a window-mounted air conditioner? This is because a large part of the job of an air conditioner is to dehumidify the air it cools. Humid air is much more expensive to cool than dry air! And of course, that freezing cold winter air that enters through the crawl space vents isn’t helping either.


Mold needs three important things to survive: Warmth, Moisture, and Food. Of these, the easiest to control in your home is moisture. Fortunately, controlling crawl space humidity is easy! At Foundation Recovery Systems, a crew of our crawl space contractors can usually install a moisture control system in less than a day.

Fortunately, controlling crawl space humidity is easy! At Foundation Recovery Systems, a crew of our crawl space contractors can usually install a moisture control system in less than a day.

We recommend starting by sealing those crawl space vents, then following up by installing a crawl space vapor barrier on the walls and floors. A dehumidifier is a great finishing touch, drying out the space and helping you to preserve your home.


Unfortunately, it isn’t just the air inside your crawl space that’s affected. In your home, warm air rises, leaving through your attic and upper floors. As this happens, a vacuum is created on the lower floors. Air from the outside, and from your crawl space, is pulled upwards to fill the space. This is known as The Stack Effect.

If you have crawl space vents, they will also become part of the air movement in your home. As air is pulled out of the crawl space and up into the home, new air will be pulled in through these vents.


Foundation Recovery Systems has been dedicated to helping homeowners solve their home repair needs since 1992. To help you decide which repairs are best for you, we offer free crawl space repair inspections to homeowners in our area. Contact us today!


Vent Cover on the crawl space of a home
Smart Vent

Crawl space door on the a home
Doors & Entryways
Moisture barrier sealing block walls in crawl space of a home
Seal Block Walls
Drainage matting close up shot
Drainage Matting

Crawl space dehumidifier installed in home

Moisture barrier installed in crawl space of home
Moisture Barrier

Contact us for a Free Inspection!