What Problems Are Caused by Expansive Soils?

Expansive soils around homes can lead to various problems affecting structural integrity. What are expansive soils, and how can you address these soils around your home?

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Have you given much thought to the soil under and around your home? Expansive soils may not seem like an immediate threat, but once you build a home, you’ll realize they’re just as destructive as other geologic hazards. They cause greater financial loss than all other natural hazards combined. All around the U.S., these soils are responsible for the majority of home structural failures and problems. 

There are residential areas within Missouri that are most likely to experience the impact of expansive soils. A soil analysis is the only thing that can lift the veil of uncertainty. In this article, we’ll cover the basics of expansive soils and what measures you can take to protect your home from damage. 

expansive soils and foundation problems

What are expansive soils? 

Swelling, expansive soils are a types of soil with water-absorbing minerals. These soils are capable of expanding or shrinking depending on the prevailing conditions. When it rains or the soil gets wet, they expand. How much they swell depends on their original moisture content, dry intensity, stratum thickness, and the ground load. These soils will keep expanding until they are fully saturated. 

Expansive soils have minerals that swell in the presence of water. The most common ones being: 

  • Vermiculite 
  • Beidellite 
  • Bentonite 
  • Nontronite 
  • Sulfate salts 
  • Chlorite 
  • Attapulgite 

What Problems Accompany Expansive Soils? 

Expansive soils absorb water. When this happens, they swell and exert pressure on your home’s foundation. Their force can cause foundation walls to crack, and these cracks will allow water to seep into your basement. This also can trigger problems like mold or mildew growth, water damage, and wood rot. 

When the weather is hot, these soils lose water and shrink. This weakens them and removes the support that provides your foundation. It’s this loss that results in soil settlement as well as foundation settlement, major causes of structural problems. 

Signs of Swelling Soils 

If you have a keen eye, you will quickly notice there’s a problem with soil on which your home’s foundation rests. Keep an eye out for foundation problems like drywall cracks, foundation cracks, gaps below doors, and sticking doors and windows. 

Possible Fixes for Expansive Soils 

There are a number of ways to treat expansive soils so they won’t swell and damage your foundation and home. Your options for stabilizing the soil include: 

  • Chemical Injection. One way of treating expansive soils is by injecting the ground with a chemical solution like potassium. Rigs with multiple injectors deliver the stabilization fluid to the soil. 
  • Moisture control. This is a preemptive measure that seeks to prevent water from seeping right into your home’s foundation. Your basement waterproofing contractor will install moisture or water barriers and below-ground drainage around your home. There are many moisture control and waterproofing options available to you, depending on your home’s unique problems and repair needs. 
  • Reinforcing the foundation. A piering system is used to stabilize the foundation and lift the sunken floor to the original position. It’s the answer to a settling home. Your foundation repair contractor will tell you what type of piers they will use. Options include helical piers, push piers, and slab piers. 
  • Reinforced slab-on-grade. Before you erect a building, create a strong foundation that can withstand soil movements and separate your house from the expansive soils. The best way to do this is to install a reinforced slab-on-grade that’s stiffened by crossbeams. 
  • Proper landscaping. Re-grade your yard to control rainwater or underground water that enters your foundation. Pay attention to your landscaping efforts by ensuring garden plants and flowers stand five feet away from your home’s perimeter and trees 20 feet away. Tree roots spread far out in search of water and will disrupt the soil structure in your foundation. Water plants using a dripline. 
  • Cement/lime treatment. Both are effective stabilizing agents that are widely used to treat various clayey soils. They reduce plasticity and the saturation limit of soils while increasing their strength. 

Foundation repairs resulting from expansive soils can be costly to fix. While some solutions halt settlement, others mask the signs for a short period. Make sure you perform soil analysis before you construct your house. A foundation repair contractor can help determine whether the soil is stable or not. 

Take the Next Step 

Expansive soils under your home shouldn’t portend the end of your foundation. You can take corrective measures to protect your foundation from settlement. Be sure to contact the experts at Foundation Recovery Systems for a free foundation repair inspection and quote in Springfield, MO. We have experience stabilizing homes with expansive soils so they won’t sink under their load or weight.