What Causes Foundation Cracks and How to Fix Them
What Causes Foundation Cracks and How to Fix Them: Know the Warning Signs and Repair Options
Cracks in your concrete foundation may seem like a minor inconvenience, but they can quickly evolve into indicators of deeper, serious structural issues. Understanding what causes foundation cracks—and when it’s time to call in the professionals—can help you avoid costly repairs and preserve your home’s structural integrity.
At Appalachian Foundation Services, we don’t just patch cracks—we identify the underlying cause and apply long-term solutions to keep your home safe and secure.
⭐⭐⭐⭐⭐
“Hunter and his crew were amazing to work with. There was a horizontal crack in the foundation of our new (but very old) house, and Hunter came out promptly to give us an assessment of the damage and an estimate on the repairs. He and his crew were timely, communicative, and super professional. They answered all of our questions and addressed all our concerns! Would recommend them to anyone needing foundation work!”
— Caroline Beatrous
9 Common Causes of Foundation Cracks
Foundation walls can crack for a variety of reasons, and not all cracks are the same. Let’s take a closer look at what may be causing the damage:
- Soil Movement
When the soil beneath your foundation expands and contracts due to changes in moisture levels, it can create uneven pressure, leading to foundation movement and cracking. - Poor Drainage
Improper drainage can cause water to pool near the foundation, increasing hydrostatic pressure on basement walls. Often results in horizontal cracks, which are among the most concerning. - Construction Defects
Poor construction techniques, such as using low-quality materials or failing to compact the soil properly, can lead to premature foundation problems, including shrinkage cracks and instability. - Temperature Fluctuations
Freeze-thaw cycles and extreme temperature swings can cause the soil and the concrete itself to expand and contract, forming hairline cracks and even diagonal cracks over time.
Additional Hidden Causes of Foundation Cracks
Beyond the usual suspects, there are less obvious but equally dangerous factors that can lead to foundation damage:
- Plumbing Leaks
A leaking pipe under your home might seem minor, but over time, it can erode supporting soil. Creates voids, resulting in foundation movement and significant cracking. - Gutters and Downspouts
Clogged or misdirected gutters may allow water to pool near your foundation. This constant exposure can cause degradation of the concrete and lead to the formation of cracks, particularly near corners and seams. - Expansive or Drying Soil
Clay-heavy soil can expand when wet and shrink during dry periods. These shifts put pressure on your foundation from below and from the sides, leading to foundation cracks, especially horizontal and diagonal ones. - Tree Roots
Trees planted too close to your home can extract moisture from the surrounding soil, potentially causing damage to your property. As the soil dries out, it may settle unevenly, putting stress on the foundation and causing structural damage over time. - Flooding and Water Intrusion
Heavy rain, poor grading, or basement leaks can saturate the soil and cause water to seep into existing cracks, thereby exacerbating foundation problems. Moisture can also lead to mold and damage inside your home.
Types of Foundation Cracks & What They Mean
Knowing the different types of foundation cracks can help you understand the severity of the issue. Still, professional evaluation is the safest route, especially when the cracks are active or worsening.
- Hairline Cracks
Often less than 1/8 inch wide, these cracks are typically caused by curing concrete or minor settling. While they may seem harmless, they can allow moisture into the home and should still be monitored or sealed to prevent issues. - Vertical Cracks
Running up and down the wall, vertical cracks are commonly caused by natural settling. Less severe than horizontal cracks, but can signal deeper problems if they are wider at one end. - Horizontal Cracks
These cracks are more serious, often caused by lateral pressure from soil or water against foundation walls. Left untreated, they can lead to bowed walls, water intrusion, and foundation failure. - Diagonal Cracks
Slanted or stair-step cracks typically point to uneven foundation settlement. They are often wider at one end and may be accompanied by sticking doors or uneven floors—classic signs of structural damage. - Stair-Step Cracks
Familiar with brick or block foundations, these may point to foundation settlement or lateral pressure. They’re a red flag for long-term structural repair needs.
Signs You May Need Foundation Repair
Spotting these early warning signs can help you avoid costly structural repairs later on:
- Wall and Ceiling Cracks
Cracks near windows, doors, or ceilings may mean your foundation is shifting. - Doors and Windows That Stick
If doors or windows are hard to open or close, your foundation may have moved out of alignment. - Uneven or Sloping Floors
Floors that dip, slope, or feel uneven can signal foundation settlement. - Bowing or Bulging Basement Walls
Walls that bulge or lean inward may be under pressure from shifting soil—this is a serious structural issue. - Water in the Basement or Crawl Space
Leaks or dampness can mean poor drainage or cracks from foundation damage. - Gaps Between Walls, Floors, or Ceilings
Visible gaps where walls meet floors or ceilings often point to foundation movement.
⭐⭐⭐⭐⭐
“They were easy to work with during all steps of getting the foundation fixed. Also, the price was half of what another company quoted, and they didn’t even find the source of the problem that caused our foundation to crack. I felt the Appalachian foundation took care to prevent any more damage and fixed up the problems we had already with the minimal amount of cost to us. The team that came out in December worked all week in the freezing rain, and they cleaned up the best they could considering the weather. I would use them again if we have any other foundation problems.”
— Amber Wise
If you’ve noticed one or more of these signs, it’s time to schedule a professional inspection. Appalachian Foundation Services offers trusted, local expertise in identifying and repairing the root cause of foundation damage.
How to Fix Foundation Cracks
Fixing foundation cracks starts with identifying the root cause. At Appalachian Foundation Services, we offer customized solutions that go beyond surface repairs.
- For Minor Cracks
- Hairline or shrinkage cracks can be filled with epoxy or a cement-based sealant to prevent moisture and pest infiltration.
- These may seem DIY-friendly, but if cracks reappear or grow, a professional inspection is crucial.
- For Structural Cracks
- Foundation piers are used to support and stabilize settling areas.
- Wall anchors and carbon fiber straps help stabilize foundation walls affected by bowing or lateral pressure.
- For Water-Related Damage
- We implement drainage solutions, such as French drains, sump pumps, and gutter extensions, to reduce water pressure around the foundation.
- For Severe or Worsening Cracks
- Extensive damage may require structural repair techniques, such as underpinning or wall reinforcement, or coordination with a structural engineer for a comprehensive solution.
When Is It Time to Call a Professional?
While some homeowners attempt DIY repairs, not all cracks are simple fixes. Here’s when to reach out to a professional foundation repair expert:
- Cracks wider than 1/4 inch.
- Active cracks that are widening or lengthening.
- Signs of foundation movement, like sloping floors or stuck windows.
- Evidence of water intrusion or high moisture in the basement.
- Any horizontal or diagonal cracks are common signs of structural issues.
If you’re seeing any of these signs, it’s time to schedule a professional evaluation.
Monitoring Foundation Cracks: A Proactive Step
If you’re not ready to repair but want to monitor a crack:
- Mark each end with a pencil and track changes over time.
- Use a ruler to measure the width every few weeks.
- If growth occurs, it’s time to call in the pros at Appalachian Foundation Services.
Foundation Repair Costs: What to Expect
The cost of foundation repair varies based on severity and the methods required:
- Minor crack repairs may cost less, but still require proper sealing and inspection.
- Major structural repairs, such as installing piers or wall anchors, are more complex but crucial for safety and long-term value.
Keep in mind: Homeowners’ insurance often doesn’t cover foundation repairs unless the damage is due to a covered event. It’s worth reviewing your policy and planning.
Why Choose Appalachian Foundation Services?
At Appalachian Foundation Services, we offer more than just repair—we provide peace of mind. We serve homeowners throughout Virginia with:
- In-depth assessments
- Professional-grade equipment and techniques.
- Transparent solutions tailored to your home.
Whether you’re dealing with hairline cracks, foundation movement, or potential foundation failure, we’re here to help.
Contact us today for a professional inspection and customized repair plan.
A small crack today could be a major problem tomorrow. Protect your home’s structural integrity with Appalachian Foundation Services—Virginia’s trusted name in foundation repair.