Concrete Lifting & Repair Methods Explained: A Complete Comparison Guide

When concrete driveways, garage floors, sidewalks, or structural footings settle, property owners face a wide range of repair options. However, not all concrete repair methods solve the same problem.

Some techniques lift sunken slabs by compacting base soil, others drive deep steel supports to bedrock for structural foundations, while cosmetic fixes only alter the top surface without fixing subterranean voids.

This master guide breaks down all 10 primary concrete lifting, stabilization, and surface repair methods so you can choose the safest, most cost-effective solution for your property.

At a Glance: Comparison of Concrete Repair Methods

Category 1: Slab Levelling & Sub-Grade Void Filling

These methods address sunken concrete slabs resting on grade (driveways, sidewalks, garage floors, patios) by injecting expanding or dense liquid materials beneath the slab to fill subterranean voids and raise the surface.

1. Polyurethane Foam Lifting (Polyjacking)

• How It Works: Technicians drill dime-sized 5/8-inch holes through the slab and inject a two-component expanding polymer. The liquid reacts beneath the surface, expanding 20 to 30 times its volume into a high-density, closed-cell structural foam.
• Pros: Extremely lightweight (2–4 lbs/cu.ft.), 100% waterproof/hydrophobic, cures in 15 minutes, requires tiny 5/8″ injection holes, will not cause secondary soil settlement.
• Cons: Higher material cost per pound than sand/cement grout.
• Best Used For: Residential and commercial slabs including driveways, garage floors, patios, sidewalks, and void filling.
• Learn More: Read our in-depth guide to polyurethane foam concrete lifting.

2. Mudjacking

• How It Works: A thick slurry of topsoil, sand, water, and Portland cement is pumped beneath the concrete using hydraulic pressure through 1.5- to 2-inch drill holes.
• Pros: Lower initial material cost than polyurethane polymers; utilizes widely available raw materials.
• Cons: Extremely heavy (100–120 lbs/cu.ft.), which often crushes weak sub-grade soil and leads to secondary settlement. Large 2-inch drill holes leave noticeable patches. Slurry can wash out if exposed to water.
• Best Used For: Budget-conscious projects on solid, non-erodible sub-grade soils.
• Learn More: See our head-to-head breakdown of mudjacking vs. polyurethane foam lifting.

3. Pressure Grouting

• How It Works: Similar to mudjacking, but utilizes a high-strength structural fluid grout injected under heavy hydraulic pressure to stabilize deep soil layers, fill large voids beneath industrial slabs, or seal dam structures.
• Pros: High compressive strength; excellent for deep subterranean void filling.
• Cons: Requires heavy specialized pumping equipment; adds massive dead load to sub-grade soils.
• Best Used For: Large-scale civil engineering projects, bridge abutments, and industrial warehouse floors.

CRITICAL WARNING: Cosmetic Surface Repairs vs. Structural Base Support

A common mistake property owners make is applying surface-level fixes like grinding or resurfacing to sunken or uneven concrete.

Grinding and resurfacing DO NOT restore support beneath the slab. They only mask or alter the top layer while leaving empty underground voids untouched. If soil erosion or settlement caused your concrete to sink, the slab will continue to settle—cracking thin overlays and requiring complete replacement down the road.

Category 2: Cosmetic & Surface Adjustments (No Sub-Slab Support)

Use these methods only when concrete has minor aesthetic blemishes or slight trip hazards and the underlying base soil is 100% stable and fully supported.

4. Concrete Grinding

• How It Works: A diamond-wheel surface grinder shaves down high edges on concrete control joints to smooth out minor lip trip hazards.
• Does It Restore Base Support? NO. Grinding removes concrete material from the top surface. It leaves hollow voids underneath untouched and thins the structural slab, making it more prone to cracking under vehicle weight.
• Best Used For: Minor trip hazards (under 1/2 inch) on public sidewalks where subterranean base soil is completely stable and budget constraints prevent slab lifting.

5. Concrete Resurfacing

• How It Works: A polymer-modified cementitious mortar overlay is squeegeed over damaged concrete to hide surface spalling, flaking, or cosmetic wear.
• Does It Restore Base Support? NO. Resurfacing only coats the top layer. If the slab continues to move due to sub-slab void erosion, the thin resurfacing overlay will crack, peel, and delaminate within 1 to 2 seasons.
• Best Used For: Structurally sound slabs with cosmetic surface scaling, freeze-thaw spalling, or micro-crazing where no soil settlement has occurred.

Category 3: Deep Structural Foundation & Piering Methods

When structural load-bearing walls, foundation footings, or heavy industrial machinery pads settle, slab-levelling foams and slurries are usually insufficient. These structural techniques drive steel or concrete deep into load-bearing strata or bedrock.

6. Hydraulic Lifting

• How It Works: Heavy-duty hydraulic jacks are positioned beneath structural concrete beams or heavy foundation footings to mechanically raise massive loads before permanent supports (grout, piers, or posts) are inserted.
• Best Used For: Massive industrial equipment pads, bridge decks, and structural foundation restoration paired with deep piers.

7. Underpinning (Poured Concrete Footings)

• How It Works: Excavators dig beneath existing shallow foundation footings in sections. Formwork is built, and poured concrete footings are installed deeper into the ground to extend the foundation’s bearing depth.
• Best Used For: Older residential home foundations, stone footings, or buildings expanding vertically with additional floors.

8. Helical Piers

• How It Works: High-torque hydraulic motors screw heavy steel shafts with spiral (helical) plates deep into the soil until reaching stable load-bearing strata or bedrock. Brackets are attached to the foundation footing to lift and stabilize the structure.
• Best Used For: Light-to-medium residential foundation repair, unstable clay soils, new construction deep foundations, and deck support.

9. Push Piers (Resistance Piers)

• How It Works: High-pressure hydraulic rams drive individual steel pipe sections into the ground using the structure’s own weight as resistance until bedrock or competent strata is reached. The foundation is then hydraulically lifted and locked in place.
• Best Used For: Heavy residential home foundation settlement, commercial foundation stabilization, and deep bedrock load transfer.

Category 4: Complete Reconstruction

When a concrete slab has reached the end of its physical lifespan or suffered total structural breakdown, lifting is no longer viable.

10. Full Concrete Replacement

• How It Works: Jackhammers and excavators demolish the existing concrete, load it into dump trucks, excavate damaged base soils, install fresh crushed aggregate base, build formwork, place rebar, and pour new concrete.
• Pros: Provides a brand-new surface; allows complete correction of deeply contaminated base materials.
• Cons: Highest cost option (2x to 3x the cost of polyjacking), long downtime (7-day cure for vehicles, 28-day full cure), heavy machinery damages lawns/landscaping, noise and environmental waste.
• Best Used For: Shattered concrete broken into dozens of small pieces, severely deteriorated surface matrix, or projects requiring structural re-engineering.
• Learn More: Read our complete comparison of concrete lifting vs. concrete replacement.

Decision Framework: Which Method Does Your Concrete Need?

To determine the ideal repair method for your property, follow this diagnostic checklist:

1.Determine the Structural Category:Identify whether the issue is a slab, surface cosmetic defect, or foundation wall.

Is the issue with a flat slab resting on grade (driveway, sidewalk, patio, garage pad) or a load-bearing foundation wall/footing?

• If foundation wall/footing: Consult a structural engineer about Helical Piers or Push Piers.
• If flat concrete slab on grade: Proceed to Step 2.

2.Evaluate Sub-Grade Support & Elevation:Check for sub-slab voids, soil washouts, or height drop.

Has the slab dropped in height, created a trip hazard, or sounded hollow when walked on?

• Yes: Base soil has settled. You need sub-slab void filling and levelling. Do not use surface grinding or resurfacing.
• No: If the slab is completely level and solid but has minor top flaking, consider cosmetic Resurfacing.

3.Assess Overall Slab Integrity:Inspect the physical condition of the slab panels.

Inspect the concrete surface for cracking and structural breakage:

• Slab intact or in 2–4 large pieces: Ideal candidate for Polyurethane Foam Lifting.
• Slab shattered into dozens of tiny fragments: Foam cannot bind fragmented pieces together. Opt for Full Replacement.

4.Select the Slab Levelling Method:Balance speed, property impact, and budget.

If the slab is suitable for lifting, choose between foam and traditional slurry:

• Choose Polyurethane Foam Lifting for zero heavy equipment, 15-minute cure times, 5/8″ micro-holes, and hydrophobic soil stabilization.
• Choose Mudjacking only if initial budget takes priority over heavy dead load weight, hole size, and washout risk.

Next Steps for Your Concrete Repair Project

Now that you understand how concrete repair methods differ, explore more details on cost, longevity, and step-by-step installation:

• Step-by-Step Installation: Read how polyurethane concrete lifting works.
• Cost Comparison: See a detailed breakdown on how much concrete lifting costs in Calgary.
• Root Causes: Discover why concrete sinks and becomes uneven in Calgary.
• Lifespan Expectations: Learn how long polyurethane concrete lifting lasts.