10 Foundation Crack Types Every
Homeowner Should Know
By MCK Construction & Remodel
April 17, 2025
Your home’s foundation is more than just concrete and steel—it’s the backbone of your entire structure. Over time, however, even the strongest foundations can develop cracks. Some are harmless. Others? Not so much.
At MCK Construction & Remodel, we’ve seen it all. Knowing the difference between a cosmetic blemish and a serious structural issue can save you money—and maybe even your home.
Why Foundation Cracks Matter
1. The Structure is at Stake
When cracks start forming, especially larger or spreading ones, they can point to issues with soil movement, improper drainage, or settling. These problems can:
- Cause uneven floors and misaligned doors/windows
- Put stress on framing and support systems
- Lead to severe structural instability or collapse if ignored
2. They Impact Your Home’s Safety
Foundation cracks aren’t just an eyesore. They can:
- Let in water, leading to mold, mildew, and rot
- Attract pests looking for a way inside
- Pose health risks, especially for kids, pets, and people with respiratory conditions
3. They Can Drain Your Wallet
Small cracks might not seem like a big deal—until they are. Left untreated, they can:
- Lower your home’s resale value
- Lead to extensive repair costs
- Result in full foundation replacement—or even demolition—in extreme cases
The Most Common Types of Foundation Cracks
Here are 10 types of cracks we often come across during our inspections in Washington homes:
1. Hairline Cracks
Often surface-level and due to shrinkage in curing concrete. Usually not serious—but monitor them.
2. Vertical Cracks
Run straight up and down. These may be caused by settling and are often easy to repair when caught early.
3. Horizontal Cracks
A red flag. These usually suggest serious pressure from outside the foundation, often due to soil expansion or water pressure.
4. Stair-Step Cracks
Common in brick or block foundations. It may indicate foundation movement—especially if uneven.
5. Diagonal Cracks
Often found near windows or corners. It can result from uneven settling and may require structural attention.
6. Wide Cracks (Over ¼ Inch)
Anything wider than ¼ inch should be assessed by a pro. It can signal significant structural movement.
7. Wet or Leaking Cracks
If water’s seeping in, you’ve got both a structural and moisture problem. Mold, mildew, and damage can follow.
8.Cracks with Displacement
If one side of the crack is higher than the other, it means your foundation may be shifting—call a specialist immediately.
9. Cracks at Foundation Corners
These can signal excessive stress in high-load areas. They may look small but hide bigger issues.
10. Multiple Cracks in One Area
A cluster of cracks is often a sign of deeper foundation failure or poor soil conditions.
When to Call the Pros
Not all cracks are created equal. Some can be filled and forgotten. Others might need structural reinforcement or waterproofing solutions. If you’re unsure, play it safe—get a professional opinion.
At MCK Construction & Remodel, we offer expert foundation inspections and repairs across the Tri-Cities and beyond. Whether it’s a quick fix or a major restoration, we’ll give you honest answers and solid solutions.
