How Soil Moisture Affects Your Home's Foundation: Understanding Soil Heave 

Water is a powerful force of nature, and its interaction with soil can have a significant impact on your home's foundation. One of the effects of water on soil is a phenomenon known as soil heave, which can cause problems for homeowners if not properly managed. 

What is Soil Heave? 

Soil heave occurs when soil expands due to an increase in moisture content. This expansion can exert pressure on the foundation of a building, causing it to move or even crack. Soil heave is most commonly associated with clay soils, which are particularly prone to swelling when they absorb water. 

Why Does Water Attract to Cool, Dry Soil? 

Water is attracted to cool, dry soil due to the principle of osmosis, which is the movement of water through a semipermeable membrane from an area of low solute concentration to an area of high solute concentration. In this case, the soil acts as the semipermeable membrane. 

When the soil is cool and dry, the concentration of solutes (such as minerals and salts) in the soil is higher compared to the surrounding area. This creates a concentration gradient, with higher solute concentration in the soil and lower solute concentration in the surrounding environment. As a result, water molecules move from the area of lower solute concentration (the surrounding environment) to the area of higher solute concentration (the soil) in an attempt to equalize the concentration on both sides of the membrane. 

Additionally, cool temperatures can reduce the rate of evaporation from the soil, allowing more time for water molecules to diffuse into the soil. This combination of factors makes water attracted to cool, dry soil, as it seeks to move from areas of low solute concentration to areas of high solute concentration to establish equilibrium. 

How Does Soil Heave Affect Your Home's Foundation? 

When soil heave occurs around a home's foundation, it can exert pressure on the foundation walls, causing them to move outward. Slab cracks are also common with soil heave. This can lead to foundation cracks, which can compromise the structural integrity of the home. In addition, soil heave can also cause uneven settling of the foundation, leading to uneven floors and other issues inside the home. 

Preventing Soil Heave 

To prevent soil heave from affecting your home's foundation, it's important to manage the moisture content of the soil around your home. This can be done by ensuring that your home has proper drainage to prevent water from pooling around the foundation. A 5% grade minimum will help make this happen. Rain Gutters and keeping Landscaping away from your foundation are also measures you can take.  In addition, For those living in high-humidity regions like Florida, maintaining a consistent moisture level in the soil can help prevent soil heave. This can be achieved by using a soaker hose to water the soil around your home during dry periods, or by installing a foundation watering system. 

Conclusion 

Understanding the relationship between water and soil is key to protecting your home's foundation from the effects of soil heave. By managing the moisture content of the soil around your home, you can help prevent soil heave and ensure the long-term stability of your home's foundation.