Solution
Mud Jacking: Lift Sunken Concrete Back to Grade
A proven, cost-effective method to raise settled slabs — without replacing them.
Let's take the first step toward a stable home.
A licensed local inspector will visit your property, walk you through every finding, and send a written estimate — no cost, no pressure.
- ✓ Licensed & Insured
- ✓ Lifetime Warranty
- ✓ Free On-Site Inspections
Mud jacking — also called slabjacking or pressure grouting — has been used to lift sunken concrete slabs for decades, and it remains the right choice for many Middle Tennessee driveways, sidewalks, patios, and garage floors where voids beneath the slab are large enough that a heavier fill material is needed. The process pumps a slurry mixture of Portland cement, water, and soil through drilled holes beneath the slab, raising it hydraulically back to its original elevation. Tennessee's clay-heavy soils can dry and shrink in summer, creating voids under concrete that mud jacking fills completely.
How It Works
Holes approximately 1.5 to 2 inches in diameter are drilled through the sunken slab at strategic locations that account for the void shape and the direction of desired lift. A pump forces the slurry mixture — a blend of Portland cement, water, and screened soil — under the slab at controlled pressure. As the slurry fills the void from the lowest point outward, hydraulic pressure builds and lifts the slab upward. The operator monitors movement closely and stops injection when the slab reaches target elevation. Holes are then patched with cement grout and finished flush. The slurry material cures to a stable, load-bearing consistency within 24 to 48 hours. Because the material is denser than polyurethane foam, mud jacking works well under heavy slabs or where very large voids require significant fill volume.
Problems This Solves
"Mud jacking is the workhorse of concrete lifting — it's been around a long time because it works. For large voids under heavy driveways or garage floors, you want a material with real density and mass. The slurry fills the void completely and supports the slab weight reliably."
How It Works
What to expect from start to finish.
-
Slab Assessment and Port Layout
We walk the slab, probe for voids, and identify the areas of maximum settlement. Port locations are marked based on the void pattern — we plan for full slurry coverage underneath the affected area, not just the lowest point.
-
Drilling
Holes of approximately 1.5 to 2 inches are drilled through the slab at the marked port locations. We use rotary hammer equipment and clean each hole of debris before injection.
-
Pump Setup and Slurry Mixing
The mud jacking pump is positioned near the work area. Slurry — typically Portland cement, screened soil, and water mixed to a consistent pumpable consistency — is loaded into the pump hopper. Mix proportions are adjusted based on soil conditions and desired cure characteristics.
-
Controlled Injection and Lifting
Slurry is pumped through each port in sequence, starting at the lowest or most-sunken area. Pressure and slab movement are monitored continuously. Injection stops at each port when slurry returns at an adjacent hole or when target lift is achieved at that location.
-
Hole Patching
Once lifting is complete and slurry has begun its initial set, injection ports are removed and the holes are filled with non-shrink grout, rodded, and finished flush with the slab surface.
-
Cure and Return to Service
Foot traffic is generally permitted within a few hours. Vehicle traffic is held for 24 hours to allow the slurry to achieve sufficient bearing strength. We provide written return-to-service instructions before leaving.
FAQ
Frequently Asked Questions
What's the difference between mud jacking and polyjacking?
Mud jacking uses a cement-soil slurry — heavier, slower to cure, and better for large voids. Polyjacking uses expanding polyurethane foam — lightweight, cures in minutes, and ideal for smaller voids and slabs where weight is a concern. We evaluate both for every project and recommend based on void size, slab type, and soil conditions.
How long before I can drive on my driveway again?
Typically 24 hours for vehicle traffic. Foot traffic is usually fine within a few hours of completion. We'll confirm the specific wait time based on the slurry mix used and weather conditions on your project day.
Will the patched drill holes be visible?
Yes. The patches are approximately 1.5 to 2 inches in diameter and will be visible on the slab surface. They'll be flush and solid, but may differ slightly in color from the original concrete. This is inherent to any slab-injection process.
Can mud jacking fix every sunken slab?
Not always. Slabs that are badly cracked, have significant structural damage, or have settled due to soil compression rather than void formation may be better served by replacement or pier-assisted lifting. We'll tell you honestly during the inspection whether mud jacking is the right call or if another method will give a more durable result.
Will my slab sink again after mud jacking?
If the root cause of settlement is addressed — drainage corrected, soil stabilized — mud jacking results are long-lasting. If the conditions that created the void persist (poor drainage, downspouts discharging near the slab, active soil erosion), re-settlement is possible. We point out contributing factors during the inspection and can recommend drainage corrections alongside the lifting work.