How Expansive Soil Impacts Your Basement And Foundation

When you’re lucky enough to live in America’s Heartland, you’re familiar with the beauty surrounding you daily. Rolling hills and blooming prairies broken up by deep river valleys make this region what it is, indeed a vision of peaceful living.

But along with these lovely natural features come clay-rich soils, which can spell trouble for your home’s basement and foundation. These are called expansive soils and can cause headaches for homeowners in this area of the country. In this blog post, we’ll delve into expansive soil, how it affects your home, and what steps you can take to mitigate its impact.

Understanding Expansive Soil

Your home’s foundation plays a crucial role in maintaining a sturdy and long-lasting home. One of the lesser-known but significant threats to a home’s foundation is expansive soil.

Expansive soil, also known as swelling or “shrink-swell” soil, expands when it gets wet and contracts or shrinks as it dries out. This constant cycle of swelling and shrinking can exert significant pressure on your home’s substructure, leading to problems like foundation settling and foundation cracks. While some settling is expected during a building’s lifespan, a minor issue becomes much more extensive as this cycle continues.

The primary reason expansive soil swelling occurs is the presence of clay minerals, such as montmorillonite, kaolinite, and illite, which have a high capacity to absorb water. When they come into contact with water, these clay minerals can expand up to 15 times their original volume. While that bodes well for agriculture, it’s not as great for your foundation.

How Expansive Soil Affects Your Home

Factors such as seasonal weather changes, landscaping, and improper drainage can influence the moisture levels in the soil, making that shrink-swell cycle damaging to your property.

The effects of expansive soil on your home’s foundation can be severe and costly if not addressed promptly. Let’s explore the key ways in which expansive soil can impact your foundation in this part of the country:

Foundation Movement And Settlement

During wet periods, expansive soil absorbs water and swells, exerting upward pressure on the foundation. This can cause foundation parts to lift, resulting in uneven floors and wall cracks. Then, during the drying period, the soil loses moisture and contracts, settling unevenly and creating gaps between the soil and the foundation, leading to further instability. As this happens repeatedly, the soil can no longer repair itself, and the gaps cause your foundation to shift from its original safe position.

Cracks And Bowing Walls

Expansive soils can lead to major foundation issues, such as cracks in both the interior and exterior of homes, basement walls bowing or leaning inward, and cracking the brickwork and masonry.

Vertical cracks often occur due to the differential movement of the foundation. As one part of the foundation moves more than another, it creates stress, leading to vertical cracks in walls and floors.

Horizontal cracks are more severe and indicate significant structural issues. They often occur when the pressure from swelling soil pushes against the foundation walls. Horizontal cracks should be taken seriously as a red flag, signaling the potential for structural collapse. Additionally, water can seep more easily into your home, leading to further damage and the possibility of mold growth.

As the foundation moves, it can cause doors and windows to become misaligned, making them difficult to open or close. This misalignment may lead to gaps around door frames and windows, allowing drafts and moisture to enter the home and further aggravating structural issues. These symptoms are often telltale signs of foundation problems associated with expansive soil.

Heaving Foundations And Driveways

Expansive soils can cause significant heaving in foundations, driveways, and sidewalks, leading to uneven surfaces that pose tripping hazards and affect your property’s overall safety and usability. These shifts not only compromise the structural integrity of your home but also create unsightly cracks and elevation changes that diminish curb appeal and property value.

Water Seepage And Damage

Expansive soils can create cracks and gaps, allowing water to seep into basements and leading to mold problems, mold growth, and wood rot. Changes in soil moisture content can exacerbate these issues, causing damp basements and crawl spaces. Soil movement can result in cracks in basement walls and floors, creating pathways for water infiltration and flooding, ultimately causing significant water damage and costly repairs.

The movement of the foundation can also affect your home’s plumbing system. Pipes may break or become misaligned, leading to leaks and further water damage. This can result in higher water bills and expensive repairs to both the plumbing and the damaged areas of the home. These leaks also attract mold and create an ideal breeding ground for pests like termites, ants, and cockroaches, compounding the damage and leading to additional maintenance challenges.

How To Tackle Expansive Soil Issues And Keep Your Home Safe

While the effects of expansive soil can be daunting, there are several steps you can take to prevent and mitigate these issues. Here are some practical tips to help you protect your home:

1. Proper Drainage

Proper drainage around your home is crucial in managing expansive soil. Using gutters, downspout extensions, and grading, ensure rainwater is directed away from the foundation. Installing a French drain or sump pump can also help manage groundwater and reduce the risk of basement water infiltration.

2. Moisture Control

Maintaining consistent moisture levels around your home can help minimize the expansion and contraction of the soil. Consider watering the soil around your foundation during dry periods to prevent excessive shrinking. Conversely, during wet periods, avoid overwatering and ensure that landscaping does not retain excess moisture near the foundation.

3. Foundation Inspections

Regular foundation inspections can help identify potential problems early on. Look for signs of cracks, uneven floors, and wall gaps. If you notice any issues, consult a professional foundation specialist to assess the situation and recommend appropriate repairs.

4. Soil Treatment

In some cases, treating the soil around your home can help stabilize it and reduce the risk of expansion and contraction. Soil treatment methods, such as soil stabilization or lime injection, can improve the soil’s properties and mitigate its impact on your foundation.

5. Professional Assistance

If you’re dealing with significant foundation or basement issues due to expansive soil, seeking professional help is essential. Foundation repair specialists have the expertise and tools to assess the damage and implement effective solutions, such as underpinning or wall stabilization.

Long-Term Solutions For Expansive Soil

In addition to preventive measures, long-term solutions can provide lasting protection against expansive soil problems. Here are some strategies to consider:

Deep Foundation Systems

Consider using deep foundation systems, such as drilled or helical piers, for new construction or significant renovations. These foundations extend deeper into the ground, bypassing the expansive soil layer and providing more stable support for your home.

Soil Replacement

Replacing the expansive soil with more stable material can be an effective solution in severe cases. This process involves excavating and replacing the problematic soil with a non-expansive fill material, such as sand or gravel.