What Type of Foundation is Suitable for Clay Soil?
Building a home without considering the soil it’s built on can have detrimental long-term effects on its structure. Expansive clay soil, for example, requires specific considerations. Understanding these challenges is crucial for achieving a safe and stable home.
This page explains everything you need to know about the best foundation for clay soil.
What is the Problem with Clay Soil?
Soils are commonly composed of sand, silt, and clay, and most don’t react much to moisture. The exception is expansive clay soil, which acts like a sponge, expanding when exposed to water and contracting with drought. Dry soil causes foundation sinking and cracking, while wet soil causes soil swelling, allowing moisture accumulation and infiltration. If you’ve ever wondered why homes require exterior waterproofing systems, this is precisely why.
When foundation water seepage occurs, it causes a domino effect of other clay soil foundation issues. Frequent water accumulation leads to infiltration into the crawl space, leading to other damage. Moisture on wooden piers and beams causes mold growth, wood rot, and pest infestations. This causes structural damage to the home, uneven floors, and other issues, posing safety hazards for your family and guests.
A solid and stable foundation is essential for preventing safety risks and protecting your investment.
Factors to Consider When Choosing a Foundation
Clay soil varies, so you must choose your foundation type carefully. Consider the following:
Soil Type
Some clays are firm and unlikely to shift, so erosion is not a concern. However, they may not support a heavy concrete slab. Other clays are soft and prone to sinking and movement, making them susceptible to soil washout and erosion.
Landscaping
Landscaping is an essential consideration when building a stable home on clay soil. If you want plants, flowers, trees, or shrubs around your home’s foundation, you must take the necessary steps to minimize the soil moisture that leads to foundation problems.
Climate
Some regions receive more rain and humidity than others. Wind and rain softens the soil, leading to erosion. This can increase the likelihood of water pooling around the foundation. It also means that the foundation is more likely to sink, causing damage like bowing foundation walls.
What is the Best Foundation for Clay Soil?
Pier and beam foundations are the best foundation type for clay soil. These foundations consist of thick wooden piers installed deep into the ground, with beams laid across the piers to support the structure above the soil and secure footings on clay soil. Implementing waterproofing measures is also wise, as runoff can affect the foundation, causing soil erosion around the piers and leading to wood rot.
Regardless of your foundation type, monitor it frequently for damage to prevent costly repairs. Many homes eventually require foundation repairs, but maintaining the strength of your current foundation for as long as possible will save you money and stress in the long run.
How to Stabilize Pier and Beam Foundations
Building on clay soil presents unique challenges. Expansive clay soil swells when wet and shrinks when dry, leading to shifting, settling, and structural damage over time. Here are some effective foundation repair solutions for pier and beam homes on clay soil:
- Adjustable Steel Support Jacks: These are installed under sagging beams or floor joists to re-level floors and provide lasting support. They’re ideal for stabilizing foundations affected by moisture-driven soil movement.
- Concrete Footings on Clay Soil: Reinforcing or replacing footings helps distribute the home’s weight more evenly. Deeper or wider footings may be necessary to prevent movement in expansive soil.
- Helical Piers: These screw-like steel piers anchor deep into stable strata beneath the active clay layer, bypassing the shifting upper soil to stabilize the structure. They’re often recommended for repairing a foundation on clay soil.
- Drainage Improvements: Proper grading, downspouts, and gutter systems reduce excess water around the home, helping to control soil expansion and contraction.
- Moisture Barriers: Installing moisture barriers or soil-injection systems can help regulate moisture content beneath the foundation and minimize swelling.
Contact Groundworks for a Free Inspection!
If you’re building on clay soil or repairing a clay soil foundation, it’s crucial to work with a foundation repair expert who understands local soil conditions and how to properly design footings on clay soil. The right repair or reinforcement can protect your home from future movement and give you lasting peace of mind.
Contact Groundworks today to schedule a free, no-obligation inspection.
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