How Dry Soil and Rain Cause Foundation Problems
Soil stability is the biggest factor in your foundation’s health. Two major factors in soil stability are dried-out soil (in other words, drought) and rain. Getting too much of one and not enough of the other can spell trouble for your foundation. But how do you fight back against those natural elements that are far outside of your control?
In this article, you learn how drought and rain affect your foundation and what you can do to prevent or repair the resulting damage. You can also learn more about our foundation repair services or get help now by clicking the button below to schedule your free inspection.
How Rain and Drought Affect the Soil Around Your Foundation
It goes without saying, the soil under your home is important. Your entire home depends on it. Your foundation is built into the top layer of soil, so if there’s a problem down there, you’re going to see its effects on your home.
You might be surprised to learn that this top layer of soil is always in motion. On the whole, this motion is very slow, but over several years, it’s almost guaranteed to act on your home in very distinct ways.
How the Soil Beneath Your Home Shifts and Settles
The natural cycles of drought (or even just relatively dry conditions) and rain are the biggest forces that set soil in motion. Here’s how:
- When it rains, the soil expands as it soaks up the water, increasing the hydrostatic pressure on your foundation.
- When conditions warm up, the water evaporates, and the soil shrinks, lessening the pressure around your foundation.
- When the soil gets almost completely dry, the soil can become brittle and form gaps (pictured here), decreasing support to your foundation.
- When it rains again, the water fills these gaps, adding even more pressure to your foundation than before.
Most Common Foundation Issues Caused by Soil Movement
Over time, this cycle of wet and dry soil moves your soil all around, causing a few major issues that damage your foundation. Here’s a quick list of the things that most often happen.
1. Foundation Settlement
Foundation settlement (AKA “differential settlement”) often results from the movement of the soil due to changing moisture levels. Here’s why:
- The soil under your foundation is comprised of several different layers, and some of these layers were dug up when your foundation was laid.
- The dug-up soil is backfilled once the foundation is in place, but it’s less dense than the soil around it. This creates a “Clay Bowl Effect” which means water is more likely to collect around your foundation than elsewhere.
- Between the twin forces of the dug-out soil layers drying out and water filling them up again, your foundation will sink and settle.
2. Foundation Heave
Foundation heave is the alter ego of settlement. It occurs when one side of your foundation begins to sink and the other side is either slightly raised or else just appears to be raised higher than the other side. The clearest sign of this is an uneven floor. Foundation heave will also cause cracks in floors, bowing walls, and sticking windows and doors.
One easy way to spot heave is to examine floor cracks and see if they form an enclosed loop (pictured here). The area inside that loop is where the greatest pressure is being exerted.
Soil Expansion and Shrinkage in North Carolina
This cycle of drought and rain is especially pronounced in regions of the United States, especially North Carolina, that feature a significant amount of clay in the soil. Soils like this are especially prone to expanding with water, sometimes increasing in volume by 10% after a substantial rain.
Likewise, they shrink a lot faster and to a more pronounced degree. when clay soil dries out, it shrinks and leaves gaps around the foundation. The volume of these shrink-swell movements is determined by several factors, such as evaporation, compaction, and the presence of below-slab depressions.
In North Carolina, Cecil soil is the most common type of soil, spanning 1.6 million acres primarily across the Piedmont region, including Raleigh, Durham, and Winston-Salem. Cecil soil has a large amount of red clay deposits that are great for agriculture but not so great for your home.
How to Know If Soil Is Causing Foundation Problems
While you may not be able to look underground to survey the soil in motion, you may notice damage in your everyday life through these common problem signs:
How To Prevent Further Foundation Damage from Soil
The first rainfall after a drought is a pivotal time for the structural soundness of your foundation. Without the right preparations and support set in place, you could face in-home flooding, leaking, and even mold.
1. Clean Out Your Gutters And Drains
Gearing up for the first substantial rain, you’ll want to make sure your existing drainage systems and gutters are clear and well-equipped to take on the long-awaited water. Ensure routinely clearing out leaves, brush, nests, or critters.
2. Install Sprinklers
If there are no local restrictions or rationing of water, it will help your foundation and home landscaping to prime your lawn, even with a little bit of water. This will help you keep an eye on water grading around your home and help ensure that water drains away from your home’s foundation and doesn’t pool.
3. Install Drywells
Drywells are underground drains used to safely dispose of excess runoff water or stormwater away from the home. This type of drainage system specifically benefits homes that suffer from negative grading (water flowing toward your home instead of away from it). Drywells are installed close to the home where it collects water and drains it to a place far from the home.
4. Invest in a Foundation Drainage System
A sub-surface drainage system, such as a sump pump in your crawl space or basement, is an underground system that removes water from within and underneath your home’s foundation. These systems are vital, especially during a flood, which is possible during the first rain after a drought due to the previous shrinkage of soil and structural damage your home may have endured.
5. Install a Dehumidifier in Your Basement or Crawl Space
Since the soil beneath your house has been without moisture for a while, the lower levels of your home may not currently suffer from excess moisture levels. When rain falls once more, moisture may have an easier way inside your home. Dehumidifiers work to control the levels of humidity your basement or crawl space experiences.
How to Repair Foundation Soil Problems
If you suspect foundation damage after a drought, acting quickly can make or break the structural integrity of your home. Since foundation problems only worsen with time, installing preventive measures or correcting foundation issues early on can save you money and stress in the long run.
Determining what’s going on with your home is the first vital step in preparing or repairing it from the stress of drought. Tar Heel Basement Systems offers free inspections with a no-obligation quote, so you can make the best decision for your home.
As professionals who specialize in foundation repair and protection, we take pride in providing these solutions for your home:
- Structural wall repair
- Helical or push piers that extend deep into bedrock
- Interior drainage
- Concrete lifting
Our goal is to give you the right repairs once so you can have peace of mind through rain or shine. Call the experts at Tar Heel Basement Systems today to set up your appointment.
What Will Happen to Your Foundation After a Drought Ends?
First, it’s important to know what indicates the end of a drought. A small drizzle is not substantial enough to end a drought, as it’s quickly soaked up by the local plant life, and then evaporated. A drought is over when soaking, heavy rain falls for long enough to deeply quench the soil and re-energize the ecosystem.
If underground soil pockets formed beneath your home, these could fill with rainwater, expand the soil, and potentially exert hydrostatic pressure on your basement or other foundation type.
Due to the change in the soil around your home after the drought, water may also drain differently. In the worst-case scenario, it will grade negatively toward your home and puddle, as opposed to being directed away. This makes your basement, crawl space, or the interior of your home more prone to flooding. Poor yard drainage may also exasperate hydrostatic pressure in the soil around your home.
Foundation Soil Damage FAQs
Yes, in cold climates, water in the soil can freeze and expand by about 9%, exerting pressure on foundations. Repeated freeze-thaw cycles can lead to soil movement and foundation damage over time.
Clay soil around your property causes many issues, but no matter what kind of soil you have around your foundation, there will always be some issues with it. Replacing the soil around your foundation requires lifting your home, digging a deep hole, replacing the soil, and rebuilding the foundation. This is expensive and unnecessary. Waterproofing and stabilizing your foundation are simpler, more effective solutions.
Every crack in your foundation or walls should warrant some concern, as they typically indicate foundation issues. Horizontal, diagonal, and stair-step cracks growing in width and gaps around windows and doors should be examined. Cracks accompanying bowing walls and uneven floors are of even more concern. Additionally, if you live in a coastal area of North Carolina with sandy soil and rising sea levels, you may be at higher risk of foundation issues.
Seeing Signs of Foundation Damage? Call Tar Heel Basement Systems!
If a drought causes you to see any foundation or wall issues, don’t hesitate to contact a foundation repair specialist. Some steps can be taken before the problem worsens and a total foundation replacement is needed.
Tar Heel Basement Systems is one of the leading foundation repair companies in North Carolina, serving homeowners from Winston-Salem to Wilmington. You can rely on our decades of experience fighting against the elements and addressing soil conditions that spell impending foundation problems.
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Michael Wilcher
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