Concrete Jacking: Methods, Cost, and When You Need It

What Is Concrete Jacking?

Concrete jacking is a repair technique that raises sunken concrete slabs back to their original elevation by pumping fill material through small drilled holes. The two main methods are mudjacking (cement slurry) and foam jacking (expanding polyurethane foam).

Both methods achieve the same end result but differ in materials, cost, cure time, and longevity. Concrete jacking works on driveways, sidewalks, garage floors, patios, pool decks, stoops, and warehouse slabs. It costs 50 to 75% less than tearing out and replacing the slab because it reuses the existing concrete.

How Concrete Jacking Works

The basic process is the same regardless of method:

1. Assessment. The contractor inspects the settled slab, measures the degree of settlement, and checks soil conditions. They determine the number and placement of injection holes needed.

2. Drilling. Small holes are drilled through the concrete surface. Mudjacking uses 1- to 2-inch holes spaced every 3 to 5 feet. Foam jacking uses smaller 5/8-inch holes.

3. Injection. Fill material is pumped through the holes into the void beneath the slab. The contractor monitors the lift using a level or laser and adjusts the flow to raise the slab evenly.

4. Patching. Once the slab reaches the target elevation, the injection holes are patched with fresh cement. Excess material is cleaned up.

5. Cure time. Mudjacking slurry needs 24 to 48 hours to fully cure. Polyurethane foam reaches working strength in about 15 minutes.

Mudjacking

Mudjacking pumps a mixture of water, soil, sand, and Portland cement beneath the slab. The slurry is heavy (100+ pounds per cubic foot), affordable, and has been in use since the 1930s. It costs $3 to $6 per square foot and works well for large, flat slabs on stable soil.

The main trade-off is cure time. You need to stay off the slab for 24 to 48 hours after the job. The slurry can also absorb water over time, which means it may erode in areas with poor drainage or high water tables.

Foam Jacking (Polyurethane Injection)

Foam jacking injects a two-part polyurethane resin that expands into closed-cell foam. The foam weighs only 2 to 4 pounds per cubic foot, is waterproof, and reaches 90% strength in about 15 minutes. It costs $5 to $10 per square foot.

Foam jacking is the better option when the slab needs to be back in service quickly, when moisture is a concern, or when the soil is soft or compressible. The lighter weight puts less load on already-weak soil, reducing the chance of re-settlement.

For a detailed comparison, see our guide on mudjacking vs. foam leveling.

Concrete Jacking Cost

Most concrete jacking projects cost $500 to $3,000 for a typical residential job.

Pricing varies by region, contractor, slab accessibility, and degree of settlement. Get two or three on-site estimates for accurate numbers. For a full cost breakdown, see our concrete leveling cost guide.

What Affects the Price

Several factors push the cost up or down:

• Slab size. Larger areas cost more total but less per square foot because setup costs are spread over more area.
• Settlement depth. A slab that has sunk 3 inches needs more material than one that has dropped half an inch.
• Soil conditions. Loose, sandy, or waterlogged soil may need stabilization before jacking, adding to the cost.
• Accessibility. Slabs behind fences, under covered porches, or near foundations may require extra labor.
• Number of holes. More injection points mean more drilling and patching time.
• Minimum charge. Many contractors have a minimum job charge of $300 to $500.

When to Jack vs. Replace

Concrete jacking is the right call when:

• The slab is structurally sound with no major fractures
• Settlement is under 4 inches
• Cracks are hairline to moderate and caused by settlement, not structural failure
• The concrete surface is in fair to good shape
• The slab is less than 25 to 30 years old
• You want to spend 50 to 75% less than replacement

Replacement is the better option when:

• The slab is broken into multiple pieces
• Settlement exceeds 4 to 6 inches
• Wide cracks run in multiple directions
• The surface is badly spalled or crumbling
• The concrete is past its useful life

A contractor who handles both jacking and replacement can evaluate your slab and give a straight recommendation. For a deeper look, see our guide on when to level vs. replace concrete.

How to Find a Concrete Jacking Contractor

Start by searching for concrete jacking contractors near you or slab jacking contractors in your area. Ask each contractor:

• What method do you recommend for my project, and why?
• Are you licensed and insured?
• What does your warranty cover?
• Can you provide references from similar jobs?

Get written estimates from at least two or three providers. Compare the scope of work, materials, warranty terms, and total price before committing. For more guidance, read our full guide on how to choose a concrete leveling contractor.

Browse concrete jacking contractors near you to start comparing.