How a Coin Can Determine if Foundation Repair is Needed

A Simple DIY Test to Assess Your Foundation Cracks

Foundation cracks can be concerning for homeowners, potentially leading to costly repairs, structural instability, and safety hazards. But how do you know if a crack in your foundation is serious?

Experts use a simple trick to determine whether a crack requires immediate attention—and all you need is a U.S. nickel.

A U.S. nickel is 2 mm thick. If you can fit a nickel into a foundation crack, it’s time to call a foundation repair expert!

Why Foundation Cracks Matter

Cracks in a home’s foundation occur due to natural settling, moisture exposure, temperature fluctuations, and soil movement. While some cracks are harmless, others indicate serious structural issues.

• Minor cracks (under 1 mm): Usually harmless but should be monitored.
• Moderate cracks (1-2 mm): Can absorb moisture and accelerate damage.
• Severe cracks (over 2 mm): Pose a structural risk and require immediate foundation repair.

Ignoring foundation cracks can lead to:

• Water damage & mold growth due to moisture infiltration.
• Increased structural instability, leading to sinking or shifting foundations.
• Higher repair costs if minor cracks escalate into major issues.

How to Perform the Nickel Test for Foundation Cracks

Step 1: Grab a U.S. Nickel

A U.S. nickel is exactly 2 mm thick, making it a perfect tool to determine whether a crack requires repair.

Step 2: Insert the Nickel into the Crack

• If the nickel does NOT fit → The crack is likely minor, but keep monitoring it.
• If the nickel fits snugly → The crack is at least 2 mm wide and requires professional evaluation.
• If the nickel fits with extra space → The crack is larger than 2 mm and may indicate serious foundation movement.

Step 3: Monitor and Measure Growth

• Mark the edges of the crack with a pencil and record the date.
• Recheck the crack every few weeks to see if it’s growing.
• If the crack worsens, develops a stair-step pattern, or expands vertically, consult a foundation expert immediately.

Understanding Crack Widths and Severity

Not all foundation cracks pose an immediate threat to your home’s structure, but knowing how to assess their severity is crucial. Cracks form due to various factors, including natural settling, moisture fluctuations, soil expansion, and structural shifts. While some cracks are purely cosmetic, others can weaken the foundation over time, leading to costly damage if ignored.

Below is a crack width severity guide to help you determine when a foundation crack requires professional attention:

• 0.1 to 0.3 mm (Hairline Cracks): These cracks are common and typically result from normal foundation settling. They do not impact structural integrity but should be monitored.
• 0.3 to 1 mm (Minor Cracks): While these cracks do not affect the foundation’s stability, they may affect the appearance of interior and exterior walls. Filling them with sealant can help prevent dust and moisture buildup.
• 1 to 2 mm (Moderate Cracks): At this stage, cracks can start absorbing moisture, leading to faster deterioration of the foundation. These cracks should be monitored regularly, especially if they appear near high-risk areas such as basement walls or crawl spaces.
• 2 mm or Wider (Severe Cracks): Cracks larger than 2 mm indicate potential structural concerns. They can cause foundation instability, water seepage, and shifting walls. These require immediate professional inspection and repair to prevent further damage.

Warning Signs of Dangerous Cracks

In some cases, cracks worsen over time, signaling a serious foundation issue. If you notice the following signs, you should schedule a foundation inspection immediately:

• Cracks are expanding or widening noticeably over weeks or months.
• Stair-step cracks appear in brick walls or exterior masonry.
• Cracks are near windows, doors, or basement walls, causing misalignment of doors and windows.
• The foundation is shifting, bowing, or separating, leading to sloped floors or visible gaps in walls.

Ignoring these warning signs can lead to structural failure, making repairs significantly more expensive.

Schedule a Foundation Inspection if you notice any of these signs.

Why Monitoring Foundation Cracks is Essential

Foundation problems rarely give warning signs until significant damage has already occurred. Regular inspections and early detection help homeowners avoid expensive foundation restoration and long-term structural instability.

Homeowners should inspect their foundations at least twice a year, especially after heavy rainfall, earthquakes, or extreme weather conditions. If you notice new cracks forming or existing cracks widening, immediate action is necessary.

What Happens if You Ignore Foundation Cracks?

• Water Infiltration & Mold Growth: Small cracks can absorb moisture, leading to mold formation, musty odors, and wood rot in basements and crawl spaces.
• Structural Instability: Over time, unattended cracks widen, weakening load-bearing walls and support structures. This can cause shifting floors and sagging ceilings.
• Sinking Floors & Misaligned Doors: Foundation shifts cause doors and windows to stick, floors to slope, and walls to bow inward. These are clear signs of serious structural problems.
• Expensive Repairs: What starts as a minor crack can turn into a major foundation issue, requiring costly piering, leveling, or full-scale restoration.

Taking proactive steps now can save thousands of dollars in future foundation repairs.

When to Call a Foundation Repair Specialist

If your nickel fits into a foundation crack, your home may need foundation repair. A qualified foundation repair specialist can provide a detailed assessment, monitor crack progression, and recommend the best repair solutions to ensure your home remains stable and secure.

Why Call a Professional?

• Early Detection Prevents Expensive Damage: Catching foundation issues early can reduce repair costs and prevent larger structural failures.
• Accurate Crack Measurement & Monitoring: Experts use precision tools to track crack expansion over time, ensuring accurate assessment.
• Long-Lasting Foundation Stabilization: Professional repairs provide permanent solutions, reinforcing your home’s structural integrity.

Final Takeaway: Protect Your Home with Routine Foundation Checks

• A simple nickel test can help determine whether a foundation crack requires immediate attention.
• Cracks under 2 mm should be monitored, while cracks over 2 mm need repair.
• Ignoring foundation cracks can lead to serious structural damage and costly repairs.

Call 919-855-0855 or Schedule a Free Foundation Evaluation today!

Frequently Asked Questions

1. Why is a nickel used to measure foundation cracks?

A U.S. nickel is exactly 2 mm thick, making it a simple and effective tool for determining whether a foundation crack requires professional attention. If the nickel fits inside the crack, it is 2 mm or wider, which means your foundation may need repairs.

2. Can foundation cracks close on their own?

No, foundation cracks do not close or heal naturally. In fact, they tend to expand over time due to soil movement, moisture exposure, and structural stress. Ignoring cracks can lead to more significant foundation issues.

3. Can weather changes affect foundation cracks?

Yes, extreme weather conditions such as heavy rain, drought, or freezing temperatures can expand and contract foundation materials, making existing cracks worse.

4. Is it normal for new homes to have foundation cracks?

Yes, minor hairline cracks are common in new homes as they go through a natural settling process. However, if cracks continue to grow or exceed 2 mm, they should be inspected by a foundation expert.

5. Can I fix a foundation crack with sealant?

While sealants can temporarily stop moisture from entering small cracks, they do not address underlying structural issues. Professional evaluation is needed for larger or worsening cracks.