Some areas of Kansas City and Moberly, MO, have clay-based soils which present unique challenges to builders, especially in wet and dry conditions. The shrink-swell properties of clay soil make it unsuitable for supporting buildings or structures as the foundation requires stable soil.
What Is Clay?
Clay is a type of soil that contains fine particles and little organic matter. It tends to absorb water fast in wet conditions and lose it in dry weather. Because they’re expansive in nature, clay soils might cause the foundation to heave and shift or crack.
How to Identify Clay Soil
You can identify clay soil by its appearance. It presents as a solid mass and is red or brown. When you rub the soil in between your fingers, it feels smooth and glossy.
Clay is less permeable, meaning it absorbs water slower than most other soils. If water is pooling around your home after a downpour, there’s a possibility your home is built on clay-based soils.
Properties of Clay Soil
Clay tends to dry out and shrink in prolonged droughts. This shrinkage under the foundation can have a similar effect to soil settlement. Usually, a section of the foundation will crack and settle into the hollow created by the shrunken clay. The gap that’s created can also allow water to collect and settle there.
In wet conditions, clay-based soils will absorb rainwater and expand. This expansion will begin to exert pressure on your home’s foundation, causing it to crack. The cracks will open up your foundation to more water, which could damage your basement, personal belongings, and the floors.
When clay soil expands unevenly, two sides of the foundation can move and change in different ways. So, it’s important to understand how to take care of this soil and spot the signs of foundation damage early on.
Improving Clay Soil
Install Proper Drainage: Ask your local contractor to install proper drains around your home. What this will do is minimize the impact of clay soil on your home’s foundation. Start with gutters and downspouts to move water far away from the foundation. Also, have a French drain installed to keep excess water out of the foundation. Waterproofing measures in your home such as an interior drainage system, sump pump, dehumidifier, and vapor barrier also are important in keeping your home dry even if the exterior clay soil is saturated and threaten to impact your basement or crawl space.
Proper grading: You also need to pair your exterior drainage system with an adequate slope. In other words, the soil around your home has to slope away six inches over 10 feet so water won’t pool around the foundation and cause damage.
Add organic matter: Another practical way of improving clay soil is to work lots of organic matter into it. In Missouri, clay soil naturally has a lot of organic matter, which can lead to drastic changes in rainy weather or drought. Two reliable remedies that can help make up for this deficiency are compost and cover crops. Experts recommend covering the soil with leafy/grassy plants like cream peas, wheat stalks and adding two inches of compost or mulch in spring to help retain moisture.
Proper yard care/maintenance: In between testing soils and installing drainage, you should also consider using a drip irrigation system in your garden. This system will reduce waste and ensure both nutrients and water go directly to your plants’ roots, minimizing the risk of pooling water or flooding.
Plant spacing: Avoid planting trees or garden plants within 10 feet of your foundation. Plants get thirsty in hot and dry summer months, and they may suck moisture from the clay soil.
Water the soil: Consider watering the clay soil that touches your foundation in the summer months so it won’t shrink and crack.
Avoiding foundation problems all comes down to regulating moisture levels in the soil year-round. It also helps to install proper drainage and maintain your yard.
If you suspect that your foundation is built on clay soil, contact Foundation Recovery System to schedule a free foundation inspection. We’ll assess the soil and tell you what sort of fix can help stabilize your foundation.