What to Do About Cracks in Basement Walls

Cracks in basement walls can be concerning for any Michigan homeowner. While some cracks are harmless and purely cosmetic, others can indicate more serious structural issues. Understanding the types of cracks, their causes, and how to address them is important to maintain a safe and dry basement. Let’s take a look at the different types of cracks in basement walls, how they occur, and what to do about cracks in basement walls.

Causes of Basement Wall Cracks

Cracks in basement walls are very common. Some of these cracks are somewhat inevitable and generally harmless, while others can be signs of bigger problems (we’ll cover this in more detail later in the post). There are a few different situations that cause basement wall cracks, including:

• Foundation settlement: Over time, the soil underneath a house shifts and settles, causing the foundation to move slightly. Outside of big seismic events like earthquakes, this shifting is generally minimal and gradual, and only causes small, thin cracks.
• Concrete shrinkage: Concrete shrinks as it dries, and this process can result in small cracks. This is generally expected, however, and doesn’t usually pose a threat to the home.
• Different concrete batches: While pouring concrete for basement walls and foundations, builders will use different batches of concrete. If these aren’t integrated properly, they can cause cold joints; spaces of separation where moisture can intrude. In some cases, cold joints are planned, and the thin cracks that result aren’t problematic. In other cases, the differences between the concrete integration is too great, and the cracks can create structural problems.
• Hydrostatic pressure: In many parts of Michigan, groundwater sits close to the surface due to clay-heavy soils, nearby lakes and rivers, and seasonal snowmelt. This is especially common in lake-adjacent communities, river corridors, and low-lying areas such as West Michigan near Lake Michigan, communities along the Grand and Saginaw Rivers, and older neighborhoods in Southeast Michigan. When soil stays saturated, it presses against basement walls and foundations, which can lead to cracking over time—particularly where drainage is limited.
• Thermal expansion and contraction: Temperature changes can cause the materials in the walls to expand and contract, leading to cracks over time.
• Poor construction: Improper construction techniques or the use of substandard materials can make basement walls more susceptible to cracking. For example, if the soil is backfilled around the concrete too soon, or without the proper reinforcement, when the house is built, it can cause more serious cracks.

Types of Basement Wall Cracks and What They Mean

You might notice a variety of different types of cracks in the basement walls. Let’s take a look at each of these according to their severity.

Harmless Cracks

Very thin cracks like these are naturally occurring and shouldn’t be worrisome, unless they are expanding over time.

You may notice thin cracks throughout the basement walls or floor. These are generally harmless and naturally occur.

• Hairline Cracks: These are very thin cracks, usually less than 1/8 inch wide. They are often due to the natural settling of the house and are generally not a cause for concern.
• Vertical Cracks: Vertical cracks are often caused by the normal settling of the house and are typically harmless, as long as they are not widening over time.

Cracks That Can Be Filled

Larger cracks, like these, can allow moisture to enter to the home. However, these can be filled.

Some cracks are more noticeable, but they don’t indicate structural damage. These can be unsightly and can be a point for moisture to enter, but they can also be filled. The industry-leading polyurethane injection method can completely seal a crack in the foundation walls, instead of just covering the surface.

• Diagonal Cracks: These cracks can be a sign of differential settlement or slight shifting of the foundation. If they are not too wide, they can be filled with epoxy or polyurethane to prevent water infiltration.
• Shrinkage Cracks: These occur as the concrete cures and dries. They are usually shallow and can be filled with sealant to prevent moisture from entering.

Cracks Needing Professional Intervention

Very large cracks, like this one, can present structural threats to the home, and require professional intervention.

Some cracks in the basement are signs of serious structural issues. The soil around the home may be shifting more dramatically, the concrete may not have set properly when the home was built, or pressure around the home may be too great, causing the walls to crack.

• Horizontal Cracks: Cracks that form left to right, or form a stair-step-like pattern, indicate structural instability. This can indicate significant pressure from water-saturated soil and may suggest a more serious issue with the structural integrity of the wall. Professional evaluation and possible reinforcement are necessary.
• Wide or Growing Cracks: Any crack that is wider than ¼ inch or is continuing to widen over time should be assessed by an expert. This could indicate ongoing movement and a potential threat to the stability of the wall.

If you have noticed cracks with these patterns or ¼ inch width in your basement walls, don’t wait – schedule a professional inspection for recommendations to keep your foundation structurally sound. Request a free StayDry® Inspection today ›

What to Do About Cracks in Basement Walls in Michigan

Now that we’ve covered the different types of cracks that you might see in the basement and what they mean, what can you do about cracks in basement walls?

Filling Small Cracks

For hairline and small cracks, using an epoxy or polyurethane injection can effectively seal the crack and prevent moisture from entering. For very thin cracks, a topical sealant can be effective.

Waterproofing Solutions

If the cracks in the basement walls are allowing moisture and water through, waterproofing solutions can help. Exterior waterproofing solutions will seal the basement from the outside, so water doesn’t intrude. Interior basement waterproofing can also move moisture away and prevent larger issues, like flooding.

Professional Repairs

For larger or more serious cracks, hiring a professional is essential. Professional foundation crack repair can seal the area completely, instead of simply covering the crack. If the crack is allowing moisture into the home, but doesn’t indicate structural damage, high-pressure professional polyurethane injection can seal the area securely.

Wall Reinforcement

For deeper, horizontal, or stair-step cracks that indicate structural issues, reinforcement will help to protect the home. Fortress stabilization uses Kevlar strips secured by anchor points to stabilize the wall and prevent further shifting. Shear reinforcement using steel rebar and anchor points, as well as steel brace reinforcement using steel I-beams, can secure the walls.

Get Expert Insight on Your Basement Wall Cracks

Cracks in basement walls are a common issue for Michigan homeowners, but not all cracks are the same. By understanding the types of cracks, their causes, and appropriate solutions, you can maintain the integrity of your basement and prevent more serious structural problems. If you’re unsure about the severity of a crack, consult a professional to ensure your home remains safe and sound.

Call 1-989-520-5851 or contact us online to get a free estimate.