Sinking foundations are common—in fact, most buildings will settle over time. The slow process of a building “getting comfortable” as the soil below it adjusts to the structure’s weight is typically no cause for concern. However, differential settlement, which happens when the soil beneath the foundation erodes away or moves unevenly, can cause severe structural damage.

Here, we’ll discuss the different types of settlement, their causes, symptoms, and solutions. If you’re afraid that your home’s foundation is settling, call AquaGuard today! We’ll schedule a free inspection, during which we can thoroughly assess your foundation for damage and recommend the best foundation repair solutions for you.

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What is Foundation Settlement?

Foundation settlement happens when soil moves beneath the home. As the soil moves, air pockets, or voids, form. Those voids cannot support the heavy weight of your foundation walls, and thus the walls themselves will start to crack and shift downward—or settle—into those voids. Whether or not this soil shifts evenly underneath your home dictates how much damage your home will incur. Fortunately, foundation settlement is easy to spot before the issue worsens over time, as the tell-tale sign of a settlement issue is vertical or stair-step wall cracks.

Graphic of home with cracked uneven foundation

The Two Types of Settlement

There are two types of foundation settlement: uniform settlement and differential settlement.

What is normal house settling?

Most buildings will settle at a slow rate. Normal, or uniform, house settling is often unnoticeable but may be accompanied by small drywall cracks that don’t get bigger over time. As the name implies, uniform settlement typically causes the home to settle evenly, leading to very minor damage or no damage at all.

What is differential settlement?

Conversely, differential settlement causes different parts of the structure to settle or heave unevenly. This can lead to interior or exterior foundation wall cracks, building frame distortion, uneven floors, jammed doors or windows, and other structural damage throughout the home. 

What Causes Foundation Settlement?

Whether due to uniform or differential settlement, all foundation settling can be traced back to soil movement. There are usually a number of different soil layers underneath a house, and the lower layers typically have a greater soil bearing capacity. Foundation settlement can occur when the structure is built on a layer of soil that can’t support the weight of the home. Uniform settlement typically occurs when the soil beneath your foundation gives into the foundation’s weight. Soil will become more compact over time as the weight of the foundation presses into it. On the other hand, differential settlement can have a number of causes, including expansive soils, soil washout, and poorly compacted fill soil.

1. Expansive Soils

In Georgia, our homes sit atop Georgia red clay, which is an expansive soil in nature. Expansive soils shrink when they are dry and expand when they become oversaturated. Without proper drainage solutions, homes built on expansive soil can become subject to constant soil movement. When wet, the soil can expand and eventually washout. When dry, it will crumble and dry out. Eventually, whether due to washout or dry-out, the soil will erode or shift away, leaving voids.

2. Soil Washout or Dry-Out

Heavy rainfall and flood conditions can saturate the soil around your foundation. Without proper landscape grading and drainage, underground streams can form and wash away the soil underneath your foundation. Your foundation will then sink or settle into the gaps. Droughts or extended periods without precipitation can cause the soil to crumble and erode away, again often resulting in foundation settlement.

3. Poorly Compacted Fill Soil

When your home was built, the builder likely cleared a large plot of dirt to form a properly-graded plot in which to build your house. This is called the Clay Bowl Effect. Afterward, your foundation footing is cast, then your foundation walls erected (if your home sits on a basement or crawl space) and floor poured (if you have a basement). Then the soil that was removed is poured back around the house. The problem is that, unlike the hard, compact virgin soil that was removed, this back-fill soil is loose and granular. This loose soil is automatically more susceptible to washout, dry-out, and erosion than the virgin soil it replaced. When the builders do not properly compact the soil before building the rest of the house on top of the foundation, it can expedite the soil’s expansion, contraction, and erosion around and underneath your home, often yielding settlement at a much faster rate as a result.

soil level graphic against home

Signs of a Sinking Foundation

The signs of a sinking foundation can appear subtle at first—unfortunately, many homeowners can go years before noticing differential foundation settlement. However, as with all foundation causes of foundation damage, foundation settlement is the easiest and least expensive to repair when caught early on.

Here are some common signs that may indicate a sinking foundation:

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Foundation Cracks

Stair-step foundation cares are one of the surest signs of a sinking foundation and are common in concrete block and brick walls. Another type of foundation crack to keep an eye out for is those that are wider at the top than at the bottom—this often indicates that the foundation is actively sinking. The wider and more uneven the foundation cracks, the more severe the displacement.
Keep an eye out for cracks that are wider at the top than at the bottom, as this is a sign of advancing settlement.

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Tilted Chimney

A tilted chimney or chimney that is separating from the home is one easy-to-spot sign of foundation settlement.

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Sticking Windows and Doors

The walls surrounding your home’s doors and windows are weak points, so signs of a sinking foundation typically show up here first. Windows and doors may not open and close properly, and there may be cracks that extend from the corners of windows and door frames.

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Cracked and Uneven Floors

A cracked, uneven slab floor may indicate foundation settlement when paired with foundation wall cracks and other signs of a sinking foundation. However, it is possible that your slab floor sank independently of your foundation. If this is the case, your foundation repair contractor can provide you with the appropriate repair solution.

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Cracks in Drywall

Cracked drywall is another common indicator of foundation settlement. Drywall cracks that may indicate foundation settlement often appear at the corners of doors and windows and along drywall seams. With that said, not all drywall cracks are indicative of a sinking foundation—the best way to determine whether your drywall cracks are a cause for concern is to call our foundation repair experts for a free inspection.

How to Fix a Sinking Foundation

The first thing you will want to do when symptoms of foundation settlement become visible is contact a foundation repair specialist. At AquaGuard Foundation Solutions, we provide a thorough, comprehensive inspection and estimate for all your foundation settlement repair needs.

We fix foundation settlement issues by installing steel foundation piers. These piers are bracketed to the footing of your house and hydraulically-driven beneath the foundation until they reach load-bearing soils that can permanently stabilize your structure.

Types of Piers for Foundation Settlement Repair

There are several different types of foundation piers, and each one is designed to address a different kind of foundation problem. We install three different patented foundation piering solutions: push piers, helical piers, and slab piers. Each of our piers are engineer-tested to provide permanent stabilization and potential lift for your home’s settling walls or slab floors.

Foundation Push Piers

Foundation push piers are straight, steel piers that attach to your foundation and extend far below the structure to strong supporting soils.

During installation, a section of the foundation footing is exposed and cut to attach to each pier’s bracket. Piers are then hydraulically-driven until bedrock is reached below—on average about 20-25 feet below your foundation, though it can be much, much deeper. Push piers can be installed from either the inside or outside of your foundation.

Foundation brackets are secured to the footing, and tubular pier sections are hydraulically driven through each bracket. Pier sections continue to be driven downwards until the piers meet competent strata, which is typically gauged at 4,000 PSI (Pressure per Square Inch). Our patented push piers are engineer-tested for load and also utilize a friction-resistance color at the base of each pier to ensure piers are driven straight and accurately, each and every time.

When all push piers have been installed, they will work in unison to transfer the weight of the structure to the strong soils or bedrock below. If possible, the home is also lifted back to its original, level position.

Foundation Helical Piers

Foundation helical piers are straight, steel piers that have helical blades welded to each shaft. This installation is completed from the exterior of your foundation.

These piers are driven into the soils underneath your foundation, then each pier is connected to the structure’s foundation via a steel bracket.

During the installation, a section of the footing is exposed and cut for each bracket. Next, round-shaft helical piers are mechanically advanced into the soil, until load-bearing strata, or bedrock, is reached. Once the helical pier has been advanced into the soil, a foundation bracket is secured to the footing.

When all helical piers have been installed, they will work in unison to transfer the weight of the structure to competent soil, permanently stabilizing and essentially providing legs for your home. If possible, the structure is also lifted back to a level position.

Slab Pier Systems

Foundation slab piers are straight steel piers that extend from stable soils deep below the structure to support brackets directly in contact with the underside of the slab.

These piers are meant to support a settling concrete floor and are not appropriate for foundation wall stabilization. Slab piers are also inappropriate for repairing heaving foundations.

During installation, a small hole is cored through the concrete floor. A slab bracket is assembled beneath the concrete slab, and steel tubes are hydraulically driven down through this bracket. When the slab piers have reached competent soils, the weight of the slab is transferred through the piers to load-bearing soils below. If possible, the slab is lifted back to level position.

At the end of the installation, PolyRenewal™ is pumped under the slab to fill any voids, and all cored holes in the slab are restored with new concrete for a clean, professional look.

Slab Piers Graphic

Slab piers can stabilize a settling concrete slab. When the soil beneath a concrete slab shrinks or settles, the slab itself is also likely to settle, often cracking and shifting in the process. Slab piers restore stability by connecting the slab to competent soil at greater depth. Slab piers are not appropriate for supporting foundation walls or repairing damage caused by foundation heave.

helical piers graphic closeup

Illustration of foundation helical piers stabilizing a home. Like push piers, helical piers are attached to the foundation by mounting a bracket. Helical piers include rotating blades that are advanced (or “screwed”) into the soil.

push pier graphic

Push piers connect the foundation to strong, stable soil or bedrock. Foundation piers attach to the base of the foundation with special brackets and extend through settling and unstable soil layers, transferring the weight of your home to competent soils or bedrock.

What Not To Do When Repairing Foundation Settlement

When it comes to foundation settlement repair, many contractors will sell a one-size-fits-all solution. Unfortunately, every house is unique and has its own challenges whether it be the type of soil it rests on or its proximity to other properties. Because of this, you need to hire a foundation repair contractor who will provide the foundation repair solution that is best for your home or business.

With that said, based on our experiences throughout Georgia, here are three fixes that we do not recommend:

Total Foundation Replacement

To completely replace your home’s foundation, the soil will have to be removed from around your home and your home will be jacked up and placed on temporary supports.

Next, your foundation walls are completely removed, and a new set of walls are constructed.
This is expensive, time-consuming, and extremely disruptive for the homeowner. To make matters worse, this process doesn’t even address the real problem—the soils around your foundation.

Many homeowners remove and replace their foundation without addressing the problem that caused the foundation issue in the first place. When this happens, they often find that after several years, they’re facing the same problem all over again.

At AquaGuard Foundation Solutions, we address the problem with warrantied solutions that will fix your problem once and for all.

Concrete Underpinning

To install concrete underpinning, the soils must be excavated from around the foundation. Larger concrete footings are poured beneath the existing footings. Once the concrete has cured, the soil is backfilled.

When it comes to foundation footings, bigger is not necessarily better. Most of the time, the underpinning will not extend beyond the problem soils under your home. If this is true, the larger footings you just paid for will continue to move and cause damage.

Concrete shrinks as it cures, and small gaps can form between the new and old footings. Open gaps beneath a home are never a good thing!

When concrete underpinning is installed and fails to solve the problem, it is much more expensive to repair. Before installing a new foundation system, all that added concrete will need to be removed.

Concrete Piers

To install concrete piers under a home, the soil will first need to be excavated from around your foundation. Short, 6″-8″wide concrete cylinders are then pushed into the soil on top of one another, strung together by a wire. Shims are then placed between the top of the concrete pier and the footing, then the soil is back-filled.

Blunt, wide concrete cylinders are difficult to push deep into the ground, making it very difficult to extend them past the poor supporting soils under your home.

Concrete can crack and break when under pressure, and even in response to temperature changes, making concrete piers a flimsy repair method.

Additionally, there is nothing to guide the direction for the pier, which means they might not be installed straight. So how will they support your home?

Because of these and other reasons, very few companies will recommend this kind of approach.

We Repair Settling Foundations in GA!

At AquaGuard Foundation Solutions, we can identify and repair any issue you may be having with settling, sinking foundations. We have a wide variety of solutions for foundation repair that have been engineer-tested and proven effective via our manufacturing network, Groundworks, throughout the United States and Canada. Groundworks is the largest residential foundation and concrete repair network in North America, and AquaGuard proudly serves as the exclusive, authorized Groundworks dealer for all of Metro Atlanta and North Georgia, including Athens, Peachtree City, Carrollton, and Rome.

Each of our solutions starts with a personal consultation with one of our certified foundation repair specialists, a thorough evaluation of your home, a customized proposal showing exactly what needs to be installed to permanently repair your home’s specific issues. To schedule an appointment with one of our specialists, call or email us today!

We proudly serve Marietta, Atlanta, Decatur, Lawrenceville, Sandy Springs, Norcross, Alpharetta, Athens, Gainesville, Blue Ridge, Cartersville, Rome, Carrollton, Fayetteville, and surrounding areas.