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The Link Between Foundation Damage And Excess Soil Moisture

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1. What Causes Foundation Moisture Problems?

Believe it or not, the number one cause of foundation trouble revolves around moisture in the soil. When foundations are built atop certain soil types, too much or too little moisture is a bad thing. Here’s why…

Not all soils are alike. Some are better suited for construction than others. The most problematic soil types for construction are expansive soils that swell – often by a considerable amount – when they soak up moisture and shrink when they dry out. This is usually seasonal and creates movement under the foundation as the soil expands and shrinks. This movement puts a lot of stress on the foundation and eventually leads to foundation problems.

So, if you want to lower your risk of foundation damage, you can start by controlling ground moisture.

For more information, see California Drought And Your Home’s Foundation.

What Causes Foundation Moisture Problems?

Most foundation moisture problems are caused by excess water in the soil around the foundation. But, where did the excess moisture in the soil come from? Here are a few ways water can build up in the soil around your home’s foundation:

Poor drainage – Water around your home’s foundation needs a way to drain off. If it can’t drain off, the soil will get saturated and cause trouble with the foundation. For example, if you have a basement foundation, hydrostatic pressure will build up in the soil and start pushing against your basement walls. This could lead to leaks, bowing, and even cracking—more on this below.

  • Rain – Excess rainfall along with poor drainage is going to lead to foundation moisture problems.
  • Melting snow.
  • Plumbing leaks – Plumbing leaks can go undetected for a long time and contribute to excess moisture in the soil around and under the foundation.
  • Yard not graded correctly – Your yard should slope away from the foundation, not toward it. You don’t want water pooling around the foundation and soaking into the soil.
  • Water-hungry shrubs, flowers, etc., next to the foundation – When you water them, you’re adding water to the soil around the foundation.
  • Clogged gutters – If your gutters are clogged, water may spill over the side of your home and into the soil.
  • Downspouts that are too short – Downspouts should deposit water away from the foundation. If they’re too short, install downspout extensions. Foundation trouble can also be caused by not enough moisture in the soil. For example:
  • Drought – Drought causes soil shrinkage, which leads to the formation of voids under the foundation. If the house sinks into the voids, you’re going to have problems.
  • Large trees – The root systems of large trees will “drink” water from the soil, leading to voids. Large trees should be at least 20 feet away from the foundation.

For more information, see Foundation Settlement.

Because there’s a connection between foundation damage and excess soil moisture, homeowners should do what they can to get groundwater under control. Doing this costs less than repairing a foundation.

If you’re having trouble with excess foundation moisture and you’re in our Northern California service area, contact us today for a free inspection and repair estimate.

Steve Egloff

Steve Egloff

Founder of Bay Area Underpinning

Steve is the Founder of Bay Area Underpinning, a foundation repair company serving the San Fransisco Bay Area, California. Bay Area Underpinning was founded in 2005 with the goal of providing a cost-effective, engineered solution to foundation settlement problems with an emphasis on educating customers to make them feel comfortable with the various methods of foundation repair.

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