What Is Foundation Settlement? Signs, Repairs, & Prevention

Crack in a block wall due to settlement.

This page provides essential information for homeowners contemplating whether their home’s foundation is experiencing settlement. We explore the signs of foundation settlement and how to fix the damage before it becomes more severe.

What is Foundation Settlement?

Foundation settlement refers to the downward movement or sinking of a home’s foundation into the soil below. Most buildings experience some kind of settlement as the soil compacts under the structure’s weight.

However, excessive settlement causes damage and occurs due to weak soil, improper compaction, moisture changes, and natural disasters. This movement leads to damage, such as foundation wall cracks, uneven floors, drywall nail pops, and other problems.

Types of Foundation Settlement

There are three primary types of foundation settlement, each with distinct features. Understanding the differences allows homeowners to address the signs early to prevent further damage. Here are the three types of foundation settlement:

Differential Settlement

The most common type of foundation settlement is differential settlement. This settlement occurs when different parts of a building sink at different rates. Differential settlement tends to cause structural damage both inside and outside the building.

Uniform Settlement

Uniform settlement occurs when foundation sinking happens at the same rate and direction throughout its structure. This settlement occurs when soil conditions are consistent across the foundation and the building’s weight is evenly distributed. Uniform settlement does not typically cause significant damage; however, when damage does occur, it leads to drainage problems, leaks, and cracked concrete sidewalks, porches, and patios.

Tilting or Racked Settlement

Tilting foundation settlement is a type of differential settlement. It occurs when one side of the foundation sinks more than the other, causing the building to tilt. This shifting happens when soil strength or moisture content varies on opposite sides of the foundation. Tilting settlement significantly strains the structure and is generally more severe than differential settlement.

Signs of Foundation Settlement

Protect your family and your home’s structural stability by recognizing these five common signs of foundation settlement.

Drywall Cracks

Drywall cracks are one of the most common signs of foundation settlement. When your home’s foundation moves, cracks form in the weakest parts of the walls (usually at the corners of doors and windows).

Don’t ignore wall cracks, even small ones. They won’t go away on their own and will only get worse.

Sticking Doors and Windows

Foundation movement causes doors and windows to become unaligned with their frames, making them difficult to open or close. This makes your home less functional and less safe in an emergency when a quick escape is necessary.

Uneven Floors

Uneven floor with a gap between the wall.

Foundation settlement causes uneven floors. As the foundation moves, so do the floors in your home. Eventually, you might see sections of flooring in your home that look warped or crooked. If you ignore these, you might deal with tripping hazards or more severe damage down the line.

Cracked Bricks

If your home has a brick exterior, you might see cracking bricks as the foundation settles. The bricks on the walls can’t stretch or bend with the movement, so they break.

You might see cracks with a stair-step pattern going up the wall. If these cracks keep getting bigger, it could mean the foundation is continuing to sink into the ground.

Leaning or Cracking Chimney

Chimney with a gap between it and the main structure.

Leaning or cracking chimneys often signal foundation issues. Built on separate foundations due to their weight, chimneys can tilt if the soil settles unevenly. This poses safety risks, potentially leading to collapse or falling bricks.

What Causes Foundation Settlement?

Foundation settlement can be caused by several factors. Here are the main causes:

Soil issues: Different soil types behave differently under load and with moisture changes. Clay soils expand and contract, while sandy soils can wash away.
Water problems: Too much or too little moisture can affect soil stability. Poor drainage, leaks, or drought can all contribute.
Poor construction: Inadequate foundation design, improper soil preparation, or substandard materials can lead to settlement.
External factors: Nearby construction, vibrations from traffic, or changes in groundwater levels can impact foundations.
Tree roots: Large trees near a structure can dry out the soil or create physical pressure on foundations.
Time and wear: Natural aging of materials and long-term soil compression can cause gradual settlement.

How to Repair and Prevent Foundation Settlement

Permanent foundation repair is achieved through professional diagnosis and repair. The following measures are taken to repair foundations that have settled:

Foundation Piers

Foundation piers are permanent support systems that stabilize settling foundations. There are three primary foundation pier types: steel push piers, spiraled helical piers, and slab piers. Each is suited for various situations but they all achieve the same goal: stabilizing a foundation.

Foundation piers are driven deep into stable soil below the existing foundation to transfer the home’s weight from unstable soil to solid, stable soil layers. Foundation piers stop settlement, restore structural stability and safety, and prevent future issues.

Channel Anchors

Channel anchors are high-strength steel rods that stabilize foundation walls with tilting on the upper side of the wall. They are installed through the foundation wall at an angle into the soil outside to redistribute the weight of the foundation and provide lateral support, ensuring structural stability.

This weight redistribution prevents further inward movement and potential collapse. Channel anchors are an effective foundation repair solution for unstable foundation walls.

Wall Anchors

Wall anchors repair bowing or inward-leaning foundation walls. They consist of a long, threaded rod attached to a metal plate installed on the interior basement wall.

The rod extends through the wall and connects to a large, anchored plate embedded in stable soil outside. The rod is tightened, and the plate is pulled inward, straightening the bowing wall and preventing further movement.

Carbon Fiber Wall Reinforcement

Carbon fiber wall reinforcement repairs cracked or bowing foundation walls, restoring stability. This lightweight foundation reinforcement consists of incredibly robust carbon fiber strips of material known for their tensile strength.

Carbon fiber straps bond to walls with epoxy resin, resisting pressure and securing cracks. This lightweight, less visually invasive method fixes moderate foundation issues.

IntelliBrace™ Wall Repair System

Our patented IntelliBrace™ wall repair system addresses bowing or tilting foundation walls from the inside. It utilizes steel beams anchored securely to floor joists and the basement floor.

This creates a strong, stable structure that can be incrementally tightened over time. By gradually pulling the beams inward, the IntelliBrace™ system straights bowed walls and restores foundation stability without requiring external excavation.

Schedule a Free Inspection with AFS Today!

Recognizing the signs of foundation settlement allows homeowners the opportunity to prevent further structural damage. AFS foundation repair experts provide proven, permanent solutions supported by over 20 years of expertise.

Our professional services offer peace of mind, ensuring your home is entrusted to the industry’s leader in foundation repair. Schedule a free inspection today to secure your home’s stability and safety.

Schedule Free Inspection

Foundation Settlement FAQs

What does foundation settlement look like in slab foundations?

When your slab foundation settles, you may see cracks along the walls, both inside and outside. You might also see one side of the concrete slab sticking up more than the other, indicating movement.

How can I tell if a crack is due to foundation problems?

Signs that a crack may be related to foundation issues include the crack being wider than 1/4 inch, the presence of stair-step or horizontal cracks, doors and windows that stick or won’t close, and cracks that continue to grow over time.

Can clay soil affect other parts of my home besides the foundation?

Yes, clay soil can cause issues with driveways, sidewalks, and other structures, leading to cracks and uneven surfaces due to soil movement.

Related Resources

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Ted Dryce

Content Writer

Ted is an SEO Content Writer who has been with Groundworks since 2021. He’s covered home repair topics ranging from crawl space encapsulation to regional soil conditions. When he’s not working, Ted is performing improv comedy and working on his own creative projects.