What Is Slab Foundation Repair?
Hundreds of thousands of Alabama homes sit on concrete slab foundations. When Alabama clay shifts beneath a slab, cracks appear and floors go out of level. APS Foundation has repaired slab foundations across the state since 1977, using both foam lifting and pier underpinning depending on what your specific situation requires. Polyurethane foam slab lifting is appropriate for moderate settlement where the underlying soil has compressed or washed away but is otherwise stable. Foam is injected through 5/8-inch holes drilled in the slab, expands to fill voids, and lifts the slab. Walk-on ready in 30 minutes. Cost is typically 50 to 80 percent less than full slab replacement. Push pier or helical pier underpinning is appropriate for significant structural settlement where the soil has failed and foam cannot provide lasting support. Steel piers are driven through the footing to stable bedrock or load-bearing strata, transferring the structural load away from the failed soil layer. This method includes a manufacturer warranty and APS's transferable in-house warranty. Huntsville note: Karst geology beneath Madison County slabs can create void conditions that require site-specific assessment before recommending foam vs. pier underpinning. APS always assesses Huntsville-area slabs before recommending a method.
How APS Approaches Slab Foundation Repair
- 1
Free On-Site Assessment
A trained APS technician visits your property, documents the problem, and identifies the root cause before recommending any repair.
- 2
Written Estimate
You receive a clear scope of work and cost with no obligation. We explain the method chosen and why, in plain language.
- 3
Repair and Transferable Warranty
Our trained crews complete the repair using professional equipment. All APS repairs carry a warranty that transfers to future owners.
What Does Slab Foundation Repair Cost?
Foam lifting: $1,500 to $6,000. Pier underpinning: $8,000 to $20,000+
Frequently Asked Questions
How do I know if my slab needs foam or piers?
Foam is typically appropriate for moderate, uniform settlement of 1 to 3 inches where the underlying soil is stable. Piers are appropriate for severe settlement, differential settlement, or situations where the soil has failed and cannot support the structure. APS provides a comparison estimate when both options apply.
Will foam last?
High-density polyurethane foam used in slab lifting is inert, non-biodegradable, and rated for decades of service. The foam does not degrade or wash away. If the underlying soil continues to shift, additional treatment may be needed.
Are the holes left in the slab visible?
The 5/8-inch injection ports are small and are patched with hydraulic cement after treatment. In most cases they are barely visible, though color matching varies with concrete age.