Skip to Main Content

6 Ways to Stop Crawl Space Moisture

water on dirt floor of crawl space

Moisture lurking in your crawl space can spell trouble in many forms, including mold growth, structural damage, and poor indoor air quality. There is a solution—crawl space encapsulation. At AFS, we’ve transformed numerous problematic crawl spaces across the Southeastern United States into dry, healthy spaces. There’s a reason homeowners end up choosing it to stop moisture in their crawl space: encapsulation actually addresses the underlying causes behind water intrusion and provides long-term protection.

Crawl Space Encapsulation: A 6-Step Solution

Crawl space encapsulation is a thorough approach that protects your crawl space from exterior elements, especially moisture. Using various components, encapsulation protects your crawl space from all types of moisture and adds defenses to the most common entry points for moisture under your home. The entire system involves several critical tools:

technician treating floor joists with soda blasting for mold

1. Mold Soda Blasting

Chances are, you’re looking into encapsulation because moisture has already caused problems in your crawl space. One of the most common problems we see in homes affected by crawl space moisture is mold growth. If there is any kind of mold growth in your crawl space, the encapsulation process starts by removing the fungus.

At AFS, we use soda blasting. Mold soda blasting is a non-toxic, environmentally friendly method that removes mold from surfaces in your crawl space without causing structural damage.

Soda blasting helps ensure that the encapsulation process begins with a clean, mold-free slate. This makes it easier for the other components of encapsulation to function at their highest ability.

encapsulated crawl space

2. Vapor Barrier

The main pillar of encapsulation, the vapor barrier, is a durable plastic sheeting applied to the crawl space floor and extended up the walls. It’s designed to prevent ground moisture from evaporating and creating a wet crawl space.

The vapor barrier’s thickness ensures longevity and resistance to tears, providing long-term protection against moisture.

3. Crawl Space Drains

Even with a vapor barrier, crawl spaces are susceptible to flooding due to heavy rains or water seepage. Installing a crawl space drainage system mitigates these issues by guiding water away from your crawl space, maintaining the effectiveness of the vapor barrier, and preventing any potential water damage.

The best crawl space drains come with a specialized filter that allows water to get inside while preventing debris from clogging. Watch the video from our friends at Groundworks to see why crawl space drainage helps prevent crawl space moisture.

Crawl space dehumidifier in encapsulated crawl space

4. Dehumidifier

In humid areas like Alabama, Georgia, Kentucky, Tennessee, and Florida, controlling crawl space moisture means tackling humidity. A crawl space dehumidifier operates to keep humidity levels in check, inhibiting the condensation that can result in mold growth and water in your crawl space.

But these aren’t your store-bought dehumidifiers. Most professional crawl space dehumidifiers can be connected to your drainage system for seamless, automatic water removal. AFS installs dehumidifiers that remove up to 100 pints of water every day—enough to keep any size crawl space safe from high humidity.

technician sealing crawl space vent

5. Vent Covers

Traditional building codes suggested open crawl space vents would allow humid air to escape from below the building. However, open vents actually allow humidity inside, and end up making the problem even worse.

This is bad because moisture under your house leads to mold growth or wood rot (two issues that severely compromise the structure of your home). By sealing these vents with covers during the encapsulation process, you will prevent humid air from entering the crawl space and add another layer of defense against moisture.

technician installing crawl space insulation

6. Thermal Insulation

Most crawl spaces were built with fiberglass insulation. Usually, this is the quicker option during construction, but it creates issues in your crawl space.

Fiberglass insulation absorbs moisture at a quick rate. When enough water is sucked up by the insulation, it becomes heavy and droops or falls to the ground.

It won’t help regulate temperatures in your home once it gets to this state. This allows your crawl space (and your home) to become extremely hot or cold, depending on the weather, and adds to structural issues.

Thermal insulation is the answer to this problem. It’s installed along the walls of your crawl space and it’s reflective, foam board design keeps it protected from moisture.

Why Crawl Space Encapsulation is the Ultimate Defense Against Moisture

Encapsulation works so effectively because it provides a multi-faceted approach to moisture control. Instead of focusing on just stopping one entry point for moisture, it focuses on stopping all of them. In doing so, the environment below your home becomes cleaner, drier, and more controlled.

This actually translates into your living space. You might notice lower energy bills, less indoor humidity, reduced pests, and floors that are more stable overall. It’s the fact that encapsulation provides all of these benefits that makes it the absolute best way to stop crawl space moisture.

The Many Benefits of Crawl Space Encapsulation

  • Prevents musty smells and odors
  • Made from virgin resins, making it naturally mold and bacteria resistant
  • Mechanical fasteners ensure vapor barrier stays secure (even with weight)
  • Brighter area with available lighting
  • Improves air quality and reduces allergens
  • Reduces potential for wood rot
  • Insulates and reduces energy costs

Common Missteps: What Won’t Stop Crawl Space Moisture

While encapsulation is a proven method to prevent crawl space moisture, it’s also important to be aware of some common DIY solutions we’ve seen homeowners turn to. While these may work for a time, they don’t address moisture issues in the same way that encapsulation does. These are only surface fixes, and over time, they prove to be ineffective:

In the Southeast United States, where humidity, rain, and hurricanes are a common occurrence, these DIY fixes won’t last. Don’t waste time or money on solutions that won’t work. Hire a professional to do the job right!

Protect Your Home with Our Professional Crawl Space Encapsulation!

Homes in the South face humid conditions pretty much year-round. At AFS, we understand that this can take a toll on your crawl space, and we have the best solutions on the market to keep your home protected. Since 2000, we’ve been serving homeowners in Knoxville, Chattanooga, Nashville, Birmingham, and surrounding areas solve their crawl space issues.

If you’re interested in experiencing the benefits that come with crawl space encapsulation, don’t hesitate to contact us. We’ll set up a free inspection at your home with one of our specialists. Then, we’ll come up with a service plan that meets your individual needs and your home’s unique situation!

OUR CRAWL SPACE EXPERTS ARE HERE TO HELP

Schedule Free Inspection
Schedule Free Inspection
AFS crew members inspecting crawl space.

Crawl Space Moisture FAQs

Without a vapor barrier, buildings are susceptible to moisture damage, which can compromise structural integrity, reduce insulation effectiveness, and promote mold and mildew growth.

When talking to experts about waterproofing their basement, a lot of homeowners question the need for a vapor barrier, especially if they say yes to a dehumidifier. After all, why apply a vapor barrier to a wall when the dehumidifier will absorb all the moisture anyway? On that note, why have a dehumidifier if there won’t be any moisture in the basement anyway due to the vapor barrier? 

The answer to those questions is that dehumidifiers and vapor barriers serve vastly different functions, which is why they are needed together. 

  • What Dehumidifiers Can and Can’t Do  

Dehumidifiers are placed in basements to make sure that the moisture levels in the space stay adequate. Dehumidifiers make sure that any microorganisms with the potential to grow into mold cannot get the moisture they need to survive. Even dry rot, which can pull in moisture from afar, has trouble thriving in basements with a dehumidifier. 

What dehumidifiers can’t do, however, is stop moisture from permeating through the concrete and cause efflorescence and weaken the concrete’s structure. If water leaks through the basement window, it will have to work overtime to get rid of all the moisture that was absorbed by the concrete. Overtaxing a dehumidifier by not controlling the amount of moisture that enters a basement decreases its lifespan. 

  • What Vapor Barriers Can and Can’t Do 

Vapor barriers block all moisture from permeating through to a basement. They keep the space dry, not by absorbing the humidity in the air, but by preventing it altogether. If any water makes its way into the basement, it prevents it from getting absorbed by the concrete, effectively preventing mold growth on the walls. In fact, it directs all water toward any parameter drainage system you have installed in your basement. 

What vapor barriers can’t do, is get rid of moisture that is already in the basement. Just because the vapor barrier is in place, doesn’t mean that water can’t ever get through. Basement windows, damaged sump pumps, leaking pipes, and broken heaters or washing machines can all cause leaking problems that increase the humidity in the basement. Once that humidity is there, problems will arise.

Insulation typically lasts 15 to 20 years, but it can succumb to damage from mold and moisture if the crawl space is not properly encapsulated. AFS Foundation & Waterproofing Specialists recommend ExTremeBloc™ foam board insulation as a durable, lasting solution. Contact us to learn more and schedule a free inspection.

Ted Dryce

Ted Dryce

Content Writer

Ted is an SEO Content Writer who has been with Groundworks since 2021. He’s covered home repair topics ranging from crawl space encapsulation to regional soil conditions. When he’s not working, Ted is performing improv comedy and working on his own creative projects.

Publish Date:

Last Modified Date:

AFS service area

Our Locations

Birmingham AL

130 Interstate Commerce Crt. Bldg. 100 & 200
Alabaster, AL 35007

Chattanooga TN

214 Industrial Park Dr.
Soddy-Daisy, TN 37379

Columbus GA

2701 Opelika Road
Phenix City, AL 36870

Dothan AL

1909 Montgomery Hwy, Suite 322,
Dothan, AL 36303

Florence AL

118 E Mobile St
Florence, AL 35630

Gulfport MS

1317 26th Ave, Ste 101
Gulfport, MS 39501

Huntsville AL

2415 Jordan Road
Huntsville, AL 35811

Knoxville TN

3028 E Governor John Sevier Highway
Knoxville, TN 37914

Louisville KY

1904 Watterson Trail, Suite 130
Louisville, KY 40299

Mobile AL / Biloxi MS

3131 Hamilton Blvd.
Theodore, AL 36582

Nashville TN

1519 Heil Quaker Blvd.
LaVergne, TN 37086

Pensacola FL

89 W. Hood Dr.
Pensacola, FL 32534