We have a musty odor from our crawlspace throughout our house. What can be done to get rid of that horrible smell?

The most common causes of musty crawl space odors are excess moisture, mold, and mildew. A crawl space provides the ideal environment for all three. Even during periods of dry weather, moisture naturally migrates upward through the soil beneath your home. That moisture is absorbed by wooden floor framing and other organic materials, creating the perfect conditions for mold growth. Over time, damp wood can also lead to wood rot and attract wood-destroying insects such as termites and carpenter ants.

Years ago, it was widely believed that venting a crawl space was the best way to control moisture by allowing outside air to circulate through the area. Today, building science has shown that this approach often has the opposite effect, particularly in our region. During the warmer months, warm, humid air enters through foundation vents and condenses when it comes into contact with cooler surfaces such as foundation walls, plumbing, ductwork, and floor framing. This added moisture can make mold and mildew problems even worse. Since concrete floors and masonry walls are porous, crawl spaces with concrete floors are just as susceptible to moisture issues as those with exposed dirt floors. In many cases, we find the most significant moisture problems located near open crawl space vents.

Another factor homeowners don't often realize is what's known as the stack effect. As warm air rises through your home and escapes through the upper levels, it naturally pulls air upward from the crawl space. That means musty odors, excess humidity, mold spores, and other airborne contaminants can be drawn into your living space, affecting the air quality throughout your entire home.

The permanent solution is to control moisture at its source. If groundwater or water seepage is entering the crawl space, an interior perimeter drainage system with a sump pump may be necessary to collect and remove water before it causes damage. In dirt crawl spaces, this typically involves trenching for the drainage system. In crawl spaces with concrete floors, sections of the floor may need to be opened to install the drain system properly.

Foundation vents should be permanently sealed and insulated to help prevent humid outside air from entering the crawl space. Once water intrusion has been addressed, the crawl space should be encapsulated with a durable reinforced vapor barrier to isolate the home from ground moisture and improve the overall environment beneath the house.

In many situations, a high-quality crawl space dehumidifier is also recommended to maintain proper humidity levels year-round. When connected to a drainage system, the unit can operate continuously with very little maintenance while helping reduce moisture, musty odors, and airborne particles. If your home relies on a sump pump, a battery backup system is also an excellent investment to provide protection during power outages, when your pump is often needed most.

By addressing the source of the moisture instead of simply treating the symptoms, you can eliminate musty odors, improve the air quality throughout your home, and help protect your home's structure for years to come.

If you have concerns about moisture in your basement or crawl space,** contact EnviroPro Basements today for a free professional inspection.** Our experts can identify the source of the problem and recommend the best long-term solution for your home.