
When it comes to protecting your home, the foundation is the most critical element. If you’re seeing cracks in your basement walls, water pooling in the lower level, or concrete that’s sinking or uneven, it’s time to call a trusted expert. At Cornerstone Structural Repair & Waterproofing, we are proud to be a leading foundation repair contractor in St. Louis County, MO, offering reliable, long-term solutions for structural and waterproofing issues. We specialize in everything from foundation crack repair and basement waterproofing to egress window installation and concrete leveling.
Contact us online or by phone today to learn more about our services or request a quote in the greater St. Louis area.
Local Expertise in St. Louis County
As a locally owned company, Cornerstone understands the unique needs of homeowners throughout St. Louis County. The homes here range from historic brick houses in University City and Webster Groves to modern builds in Chesterfield and Ballwin. Many of these homes share similar concerns:
- Aging or shifting foundations
- Water intrusion during heavy rain
- Uneven driveways and sidewalks
- Outdated or non-code-compliant basement windows
These problems are often due to our region’s expansive clay soils, changing weather patterns, and older construction practices. Our experience in the St. Louis area gives us the insight to diagnose and fix these issues effectively, using proven methods and materials that last.
Cities We Serve in St. Louis County Include:
- Chesterfield
- Ballwin
- Maryland Heights
- Florissant
- Kirkwood
- Clayton
- Creve Coeur
- Webster Groves
- University City
- Wildwood
- Oakville
If you’re located in or around any of these communities, you can count on Cornerstone for dependable service backed by years of local experience.
Our Services: Foundation, Waterproofing & More
Foundation Crack Repair
Foundation cracks are a common concern across St. Louis County, especially in older homes. Cracks can form due to hydrostatic pressure, soil movement, or natural settling. We repair both horizontal and vertical cracks in poured concrete and block foundations using high-performance injection systems and stabilization techniques.
Basement Waterproofing
Wet basements are not only a nuisance, they can also lead to serious structural damage and health issues from mold and mildew. Our waterproofing services include:
- Interior drainage systems
- Exterior waterproofing membranes
- Sump pump installation and upgrades
- Vapor barriers and moisture control systems
We ensure your basement stays dry and protected year-round.
Egress Window Installation
If you’re finishing your St. Louis area basement or adding a bedroom below grade, an egress window is essential for safety and code compliance. Our team handles all aspects of egress window installation, from excavation and drainage to professional finishing. You’ll benefit from added natural light, improved ventilation, and peace of mind.
Concrete Repair and Leveling
Uneven or sunken concrete slabs are both unattractive and hazardous. Our concrete leveling solutions use advanced polyurethane foam injection to raise and stabilize sidewalks, patios, garage floors, and driveways. It’s a quick, effective, and less invasive alternative to full replacement.

Why Homeowners in St. Louis County Trust Our Foundation Repair Contractors
- Locally Owned & Operated: We’re based in the St. Louis area and understand the specific challenges homeowners face here. We’re not a franchise or a fly-by-night operation—we’re your neighbors, and we care about our community.
- Decades of Experience: Our team brings over 70 years of combined experience in structural repair, waterproofing, and concrete leveling. We’ve seen it all, and we know how to fix it.
- Honest Assessments: We take pride in our transparent, no-pressure consultations. We’ll walk you through your options and never recommend a solution you don’t need.
- Quality Workmanship: From the materials we use to the way we clean up after every job, we’re committed to delivering quality that lasts. Many of our services are backed by strong warranties.
FAQs: What Homeowners in St. Louis County Want to Know
How do I know if I need foundation repair?
Look for signs like cracks in walls or floors, doors and windows that stick, or gaps around window frames. If you notice any of these, it’s best to schedule a professional inspection.
Do you serve all of St. Louis County?
Yes! We proudly serve homeowners across the entire county, including cities like Kirkwood, Chesterfield, Florissant, and Ballwin.
Is basement waterproofing a good investment?
Definitely. A dry basement prevents mold, protects stored items, improves air quality, and increases usable living space and home value.
How long does concrete leveling take?
Most projects can be completed in just one day, with minimal disruption. You can often use the area again within hours.
Can you install egress windows in older homes?
Yes. We regularly install egress windows in homes of all ages. We handle excavation, drainage, and finishing to meet code and maintain curb appeal.
Call Our Foundation Repair Contractor in St. Louis County for a Free Estimate
If you’re looking for a trustworthy foundation repair contractor in St. Louis County, MO, Cornerstone Structural Repair & Waterproofing is here to help. From minor cracks to full-scale waterproofing systems, our solutions are designed to protect your home and restore your peace of mind.
Call us today at 314-262-6277 or contact us online to schedule a free, no-obligation estimate. Let Cornerstone be the foundation of your home’s strength and safety.

