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7 Signs Your Concrete Foundation Needs Repair

Your foundation is the most important structural element of your home. Catching problems early can save you tens of thousands of dollars in repairs. Here are 7 signs that your foundation needs professional attention.

The 7 Warning Signs

1. Horizontal cracks in basement walls. Vertical cracks are common and usually caused by normal settling. But horizontal cracks are serious — they indicate lateral pressure from soil pushing against the wall. This is especially common in Illinois where clay soil expands when wet and contracts when dry.

2. Stair-step cracks in brick or block foundations. These cracks follow the mortar joints in a stair-step pattern and indicate differential settling — one part of the foundation is sinking faster than another. Small stair-step cracks might be cosmetic, but if they're wider than 1/4 inch, get them checked.

3. Doors and windows that stick or won't close properly. If doors that used to close fine are suddenly sticking, your foundation may be shifting. This causes the door frames to go out of square. Check multiple doors — if several are affected, it's likely a foundation issue, not just humidity.

4. Gaps between walls and ceiling or floor. Visible gaps where walls meet the ceiling or floor are a clear sign of foundation movement. The foundation is pulling away from the structure above it. This requires immediate professional assessment.

When to Call a Professional

5. Sloping or uneven floors. Place a ball on the floor — if it rolls consistently in one direction, your floor isn't level. Some settling is normal in older homes, but noticeable slopes indicate foundation issues. A laser level can confirm the severity.

6. Water intrusion in the basement. Persistent water in your basement — especially after rain — can indicate foundation cracks that are letting groundwater in. Beyond the immediate water damage, this moisture accelerates further foundation deterioration through freeze-thaw cycles.

Prevention Tips

7. Bowing or bulging basement walls. If your basement walls are curving inward, the lateral soil pressure has exceeded the wall's capacity. This is an emergency — bowing walls can eventually collapse. If you see this, call a foundation specialist immediately.

While ZBL Concrete specializes in flatwork (patios, driveways, walkways), we see foundation issues regularly during our work. We'll always tell you honestly if we spot something concerning during an estimate visit. For foundation repairs, we can recommend trusted specialists in the area. Call (312) 721-0835 with any concrete questions.