Foundations

As Franklin County’s premier foundation builder, Unerstall Foundations & Flatwork Inc has the expertise, equipment, and capabilities to handle all of your concrete construction needs.

Based in Union, MO, we provide a diverse range of affordable foundation installation services for residential and commercial clients throughout the Greater St. Louis metro area. We also provide flatwork services, foundation repairs, and install insulated concrete foundations.

Start building a strong & reliable foundation. Call us to schedule a free estimate!

Call 636-584-1052

Sump pump services by Unerstall Foundation & Flatwork

Foundation Installation

Constructing a strong concrete foundation is essential to safeguarding the integrity and safety of your new project. We’ll work closely with you to develop results-driven solutions for all your concrete and foundation construction needs. We utilize a state-of-the-art robotic total station for optimal accuracy.

Looking for a more energy efficient foundation/home? Insulated concrete forms can help!

Learn more

We pour concrete foundations for the following types of projects

New homes
Room additions
Modular homes
Garages
Commercial projects
Retaining walls

What other foundation services do we offer?

Excavation
Egress window installation
New window & well installation
Drain pipe installation

What can you expect during a foundation installation project?

Our team will meet with the customer to go over their needs, shoot the grades and elevations, and address issues with drainage and accessibility. We will then lay out the footprint for the structure so excavation can begin.

Once the area is excavated, we will begin pouring you a new concrete foundation and install the drain tile and damp proofing.

Block Foundations

Larger and heavier homes traditionally have stacked concrete block foundations.

If you’d like to explore the possibilities of a concrete block foundation for your upcoming new construction project, contact us today. One of our foundation builders is happy to assist you and answer your questions.

Drain Tile & Damp Proofing Installation

Damp proofing and waterproofing your new foundation is essential to its longevity, integrity, and safety; however, they are not the same techniques.

Whether you opt for interior/exterior drain tile waterproofing or damp proofing (or both), our foundation builders will custom-design a system that protects your foundation for the long-term.

Block foundations vs. poured concrete foundations: Which is right for you?

Typically seen in older homes, concrete block foundations are still a viable option for new construction projects. Because the concrete blocks are already solid and prepared, they don’t require the same amount of curing time as poured concrete.

With that said, if you are constrained for time on your upcoming construction project, a concrete block foundation may be the best option – especially if you are building a larger and heavier home or building.

Due to their grout lines, concrete block foundations are more prone to leaks and water damage. If you decide to install a concrete block foundation, our contractors will design and build a proper waterproofing system.

What’s the difference between damp proofing vs. drain tiling?

Damp Proofing is a coated treatment applied to foundations, basements, or crawl spaces. Once sprayed, the asphalt coating functions as a moisture barrier and prevents water and humid air from passing through the foundation.

Damp proofing does not seal cracks or holes in the foundation, nor does it serve as a waterproofing or drainage system.

Drain Tiles function as a drainage system. These porous pipes can run along with the interior or exterior of a foundation and redirect water away. They are especially beneficial in areas that are prone to heavy rain and snow. We can also provide sump pump installation in conjunction with a drain tile system.

If you’d like to explore your options for waterproofing vs. damp proofing, contact us today!

Foundation FAQs

What types of foundations do you build and which is best for my project?

We construct both poured concrete and concrete block foundations. Poured foundations are ideal for a precise, monolithic structure, while concrete block foundations cure faster and are well-suited for larger, heavier buildings.

What is an insulated concrete foundation (ICF) and what are the benefits?

An ICF foundation combines concrete with insulation blocks to form strong, energy-efficient walls. Benefits include up to 30–50% reduced heating/cooling costs, moisture resistance, noise reduction, and superior durability—even in extreme weather.

Do you include waterproofing or drain tile in foundation installations?

Yes. We offer custom designs that include interior or exterior drain tile and damp-proofing systems as part of your foundation build to protect against moisture damage and increase foundation longevity.

How do I know if my foundation needs repair?

Look for signs such as cracks in walls or floors, bowing basement walls, doors/windows sticking or misaligned, or water leaks. These issues signal settling or structural movement that should be assessed immediately.

What methods do you use when repairing foundations?

We stabilize and elevate foundations using techniques like underpinning with piers or slab jacking. Post-lift, we seal around the piers and restore soil levels to secure the structure and prevent future movement.

Can I stay in my home during foundation repairs?

In most cases, yes. Repairs may cause noise, some soil excavation, and limited access to certain areas, but our team aims to complete work efficiently and minimize disruption.

How much does foundation repair typically cost?

Minor hairline cracks may cost a few hundred dollars, while significant structural repairs can range from $2,000 to over $8,000—potentially up to $25,000 for major work. We provide detailed estimates, usually free, after inspection.

What is the typical timeline for fixing a foundation issue?

Simple crack repairs can take a few days. More extensive underpinning jobs may extend to a few weeks, depending on damage extent, soil conditions, and method used.

Will foundation repair damage my landscaping or lawn?

We take great care to preserve your property—using tarps, plywood, and transplanting shrubs thoughtfully. Still, some disruption is expected; we’ll discuss this before starting and do our best to restore the area.

What maintenance can prevent foundation problems?

Keeping soil moisture consistent and ensuring proper drainage away from your foundation is key. Installing gutters, grading your yard, and possibly adding French drains can significantly reduce settlement risks.