Imagine discovering a small crack in your basement just before putting your house on the market or right when you move in— it's situations like these where a thorough understanding of foundation inspections can make a huge difference.

Foundation inspections are a critical aspect of homeownership, ensuring your home stands on a solid and safe foundation. By regularly inspecting your foundation, you can catch potential issues early, saving you from expensive repairs and maintaining the value of your property.

In this comprehensive guide to foundation inspections, we'll cover everything you need to know, from understanding different types of foundations to identifying common issues and exploring repair options. After all, you don’t want your house to end up looking like the Leaning Tower of Pisa!

Types of Foundations

Before we dive into potential foundation issues, let’s look at some of the different types of foundations:

1. Concrete Foundations

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Concrete foundations are known for their durability and strength. Typically made of poured concrete reinforced with steel bars, they provide a stable base for lots of residential buildings. There are a few types, each suited for different environmental conditions and structural requirements:

  • T-shaped: These foundations are typically used in areas prone to freezing temperatures, like Illinois.

  • Slab-on-grade: As a single, thickened concrete slab, these foundations serve as both the floor of the building and the foundation.

  • Frost protected: This is designed for structures in cold climates where freezing of the ground poses a threat to traditional foundations.

2. Slab Foundations

Slab Foundations

Slab foundations consist of a single 4-to-6-inch layer of concrete poured directly onto the ground. They are cost-effective and popular in regions with warm climates and low soil moisture content. Slabs also help keep pests out, as there is no open space underneath the home they can reach.

3. Basement Foundations

Basement Foundations

If you have storage space underground, basement foundations are submerged below ground level to create additional living or storage space. They usually require proper waterproofing to prevent any moisture-related issues commonly associated with basement structures. There are three common structures:

  • Full basement: The entire basement floor is levelled underground, usually with no windows. This makes it more susceptible to moisture.

  • Daylight basement: This structure is built when the building rests on a slope, the present windows help to limit moisture.

  • Crawl space basement: These foundations are a small space between the ground and base of the building, which helps to encourage airflow under the structure and keep things cool in warmer climates.

4. Manufactured/Mobile Home Foundations

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Manufactured and mobile homes are typically supported by transportable foundations, providing stability while allowing for mobility. The pier and beam structure is most common, which uses one or more metal platforms placed under the foundation piers.

Types of Homes and Their Foundations

Types of Homes and Their Foundations

Now that you have an idea about the types of foundations and maybe, thought about which one you have, it’s important to understand the relationship between home types and their foundations.

1. Residential Foundations

Residential homes vary widely in foundation types, including concrete, slab, and basement foundations. Each type has specific considerations based on the property's location and structural requirements. A concrete slab foundation is one of the most common types because it makes preparation of the lot more efficient, so you can see what the built home looks like quicker.

2. Commercial Foundations

Commercial buildings often require deeper and more robust foundations to support larger structures and heavier loads. Foundations may include deep piles or specialized techniques to ensure stability.

  • Low-rise buildings: When a commercial building takes up a lot of space as a low-rise office building, a shallow foundation can spread the building’s weight across the foundation.

  • High-rise buildings: Builders usually make deeper foundations for the skyscrapers you see in Chicago or New York City.

3. Manufactured Home and Mobile Home Foundations

Manufactured and mobile homes mainly use pier and beam foundations because of their flexibility and easy installation. These foundations can support the lightweight construction of manufactured homes effectively.

Common Foundation Issues

Sometimes, foundation issues don’t reveal themselves until a ceiling sags or it smells like mildew. While it may be scary to think about, foundation issues can vary in size and extremity, so it’s better to proactively identify foundation issues early so you don’t get a $10,000 bill later.

These are some of the most common foundation issues:

  • Cracks: Internal and external cracks can sometimes be harmless from settling. However, there are some cases where cracks signify something more serious. Internal cracks that run diagonally along the floor or ceiling, and peeling wallpaper can all be signs of a foundation problem that requires professional attention. External cracks wider than a quarter of an inch, that are growing quickly or displacement of foundation footings, is a sign there is a larger issue.

  • Sagging floors: If your floor is uneven, this can occur because your home’s foundation shifts or settles, which can make the support beams separate and the walls compress. One way to know if your floor is sagging is if doors or windows “stick” when trying to open or close them.

  • Water Damage: Moisture, mold, or mildew in basements or crawl spaces as well as standing water in basements or musty smells are other signs of a greater foundation issue.

  • Structural Damage: While structural damage can be difficult to see, there are tell-tale signs to look out for like bowing walls, leaning chimneys, or gaps between walls and ceilings.

Foundation Inspection Process

So, what does a foundation inspection consist of? A typical foundation inspection involves a detailed assessment of the foundation's condition. This includes examining visible signs of damage, assessing structural integrity, and evaluating potential risks such as soil erosion or inadequate drainage.

Foundation Inspection Checklist:

Exterior Inspection

  • Examine foundation walls for cracks or shifts, especially around corners, windows, and doors.

  • Check for bulging or leaning walls using a level tool.

  • Look for discoloration or changes in surface texture.

  • Inspect the roof and gutters for leaks and ensure gutters are directing water away from the foundation.

Interior Inspection

  • Look for cracks in the floors, walls and ceilings, and check for uneven or sloping floors.

  • Ensure all doors and windows open and close smoothly.

Drainage Evaluation

  • Ensure the ground slopes away from the foundation.

  • Verify all gutters or downspouts are clear and properly direct water away.

Basement/Crawl Space Inspection

  • Look for dampness, water stains, and mold.

  • Check for leaks or loose pipe fittings.

  • Look for signs of termites or ants.

  • Notice any musty smells indicating mold or mildew.

  • Inspect for cracks or discoloration.

  • Detect indicators of moisture problems and potential damage.

Cost of Foundation Inspections

Understanding the costs associated with foundation inspections can help you budget effectively. The average cost of a foundation inspection ranges from $300 to $800. Factors influencing the cost include the size of the property, location, foundation type and any additional tests needed such as a pest inspection or roof inspection.

Also, the type of foundation plays a significant role in the cost breakdown for a professional foundation inspection.

Cost Breakdown by Foundation Type

  • Concrete Slab: This is the easiest and least expensive type of foundation to inspect.

Average Cost: $300 – $600

  • Unfinished Basement: These inspections are often more comprehensive, focusing on moisture intrusion and structural issues.

Average Cost: $350 – $700

  • Finished Basement: These are more challenging to inspect due to walls, flooring, and other structures present.

Average Cost: $500 – $800

  • Crawlspace: Inspections may take longer because of confined spaces and difficult access.

Average Cost: $400 – $700

  • Pier and Beam: This is a difficult inspection involving the condition of the beams, piers, and the crawl space underneath.

Average Cost: $500 – $1,000

Foundation Inspection Services

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When selecting a foundation inspection service, homeowners should expect comprehensive assessments and clear, actionable reports. WIN Home Inspection offers professional foundation inspections tailored to your property's unique needs, ensuring thorough evaluations and expert recommendations based on data-driven techniques. Reach out to your local WIN home inspector to learn more about options if you haven’t had a foundation inspection within the last few years.

Foundation Repair Options

Maybe it is only a small crack you notice. However, waiting until the damage is significant will only be worse for your pockets. Timely foundation repairs are crucial for maintaining the structural integrity of your home. There are several ways foundations can be fixed.

Common Foundation Repair Techniques

  • Underpinning: Strengthening the foundation by extending it deeper into the ground. This repair technique can typically last the life of the home.

  • Slabjacking: Lifting sunken concrete slabs by injecting grout underneath.

  • Waterproofing: Sealing foundations to prevent water infiltration and damage.

Foundation Repair Costs

Repair costs vary based on the severity of damage and repair method. Minor repairs may start around $500, while major repairs can exceed $10,000. The average repair cost falls around $5,400.

DIY vs. Professional Repairs

While DIY repairs may work for minor issues, like filling small cracks, significant foundation problems require professional expertise to ensure safety and compliance with building codes.

DIY efforts can be an appealing option for homeowners looking to save money and take immediate action. The primary advantage of DIY repairs is cost-effectiveness as materials and tools are generally less expensive than hiring professionals. Additionally, tackling foundation issues on your own can provide a valuable learning experience, increasing your understanding of home maintenance. However, DIY repairs come with significant limitations, including a lack of expertise and the potential for costly mistakes. Safety is another concern, as improper handling of structural issues can lead to severe accidents or further damage to your home.

Professional foundation repairs offer a higher level of expertise and access to specialized tools and techniques, ensuring the job is done correctly and safely. Professionals are well-versed in diagnosing and addressing a wide range of foundation issues, often providing warranties for their work, which adds an extra layer of security. However, these services come at a higher cost. Despite the increased expense, the benefits of professional repairs—such as precision, safety, and long-term reliability—often outweigh the disadvantages, particularly for complex or severe foundation problems.


Regular foundation inspections are essential for safeguarding your home's value and structural integrity. By understanding the types of foundations, common issues, inspection processes, and repair options discussed in this guide, homeowners can proactively address foundation concerns. We hope you’ll use this guide to stay vigilant and ensure your home remains a secure and stable investment for years to come.

Frequently Asked Questions

Q: Does a home inspection check the foundation?

A: WIN’s Full Home Inspection provides an assessment of visible foundation conditions, among 300+ other items in and around the home. For a more detailed analysis, specialized inspections are recommended.

Q: What are the signs of foundation problems?

A: Signs include cracks in walls or floors, uneven floors, sticking doors/windows, and indications of moisture or mold in basements or crawl spaces. Be on the lookout for any issues.

Q: How often should you inspect your foundation?

A: It’s recommended to get foundation inspections every three to six months or at minimum annually, especially before and after extreme weather events or significant ground movements.