How Polyurethane Concrete Lifting Works: Step-by-Step Process & Owner Guide

Sunken, uneven concrete driveways, walkways, and patio slabs are more than an eyesore—they are tripping hazards and water-drainage liabilities. Modern polyurethane concrete lifting (often called polyjacking) restores settled concrete to its original elevation in hours without demolition or heavy machinery.

Unlike traditional methods like mudjacking or complete concrete replacement, polyurethane lifting uses expanding structural foam injected beneath the slab to fill subterranean voids, compact loose soil, and raise concrete with millimeter precision.

At a Glance: What to Expect

The 11-Step Polyurethane Concrete Lifting Process

Concrete slab lifting requires strict scientific precision. Injecting high-density foam too fast or in the wrong sequence can cause slab stress, while improper void filling leads to recurring settlement.

Here is how our technicians execute a precision concrete lift from initial inspection to final cleanup:

1. Comprehensive Site Inspection: Evaluating sub-grade soil, slab condition, and root causes.

Before any lifting begins, technicians inspect the concrete surface and surrounding drainage. We identify why settlement occurred—such as poor soil compaction, freeze-thaw erosion, or downspout washouts (learn more in our guide on why concrete sinks in Calgary). We also check for structural cracking to confirm the slab is suitable for lifting.

1. Laser Elevation Measurements: Establishing target height and pitch with optical lasers.

Using optical laser levels and elevation rods, we measure the precise pitch and drop of the sunken slab relative to adjacent structures, foundation lines, or door thresholds. This benchmark data determines exact lift targets to ensure proper water runoff away from your property.

1. Injection-Point Planning: Mapping micro-injection points for balanced lift.

Technicians calculate the optimal grid pattern for injection points. By spacing holes strategically across the slab, we ensure high-density polyurethane foam distributes evenly under both the center and edges, preventing uneven stress points.

1. Precision Micro-Drilling: Micro-drilling 5/8-inch access ports.

Using specialized concrete drills, we core penny-sized (5/8-inch) holes through the slab. Compared to traditional mudjacking—which requires massive 2-inch holes—these micro-ports cause minimal surface disruption and preserve the integrity of your concrete.

1. High-Density Foam Injection: Injecting dual-component expanding polyurethane foam.

Tapered injection ports are locked into the drilled holes. Specialized equipment mixes two liquid polymer components at the gun head. As the liquid enters the sub-grade space beneath the concrete, a chemical reaction occurs within seconds, expanding the material into high-density structural foam.

1. Controlled Slab Lifting: Continuous optical monitoring during expansion.

As the foam expands up to 20 to 30 times its liquid volume, it generates tremendous upward pressure. Technicians monitor laser levels continuously during injection, lifting the concrete incrementally by fractions of an inch until it locks flush with surrounding surfaces.

1. Sub-Slab Void Filling: Consolidating weak base soils and filling empty pockets.

Lifting the slab is only half the job. The expanding foam flows into hidden underground pockets, tree root cavities, and eroded channels. This process stabilizes loose base soils and creates a solid, water-resistant foundation under your driveway, garage floor, or patio. Read more on our dedicated void filling and soil stabilization page.

1. Hole Sealing & Finishing: Filling ports with color-matched grout.

Once the slab is locked at grade, injection ports are removed. The 5/8-inch holes are thoroughly cleaned and packed with a non-shrink, cementitious masonry grout. We custom-blend the surface plug to match your existing concrete’s color and texture as closely as possible.

1. Final Quality & Elevation Inspection: Verifying pitch, flush joints, and drainage alignment.

We re-measure the entire surface with optical lasers to confirm the target elevation, proper slope away from building foundations, and seamless transitions across control joints.

1. Site Cleanup & Protection: Removing all dust and restoring the work site.

Drill dust and debris are vacuumed immediately. Work areas are swept clean, leaving your property looking as neat as when we arrived—with no muddy residue or heavy tracks left behind.

1. Return-to-Use Guidance: Immediate return-to-service timelines.

Because polyurethane foam cures to 90% full compressive strength within minutes, your concrete is ready for immediate foot traffic and vehicle parking almost right away.

Property Owner FAQ: What to Expect On-Site

Property owners frequently ask about logistics, equipment, site access, and downtime during concrete leveling. Below are answers to the most common questions regarding our lifting procedure.

Am I required to be present during the concrete lifting process?

No, you do not need to take a day off work or stay home while the service is performed.

As long as our technicians have clear access to the work area (e.g., unlocked gates for backyards) and an exterior water source or power outlet if needed (most of our mobile rigs are completely self-powered), we can perform the job while you are away. We complete the initial inspection, perform the lift, clean the site, and send you digital before-and-after photos along with your final invoice.

Will there be heavy equipment on my lawn or property?

No. There are no heavy excavators, skid steers, or concrete mixer trucks driven onto your property.

All our pumping equipment, foam supply tanks, and power systems remain housed inside our custom mobile service truck, which stays parked safely on the street or in your driveway.

• Long, lightweight delivery hoses are run directly from the truck to the work area.
• The hose laying on your ground weighs very little, avoiding any damage to grass, flowerbeds, or decorative paving.

How are my yard and landscaping protected during concrete lifting?

Polyurethane foam lifting is one of the cleanest, least invasive exterior repairs available:

• Zero Lawn Ruts: Because no heavy machinery rolls over your grass, your lawn remains completely undamaged.
• Dust Containment: Core drilling produces minimal dust, which is captured using HEPA-vacuum attachments at the drill site.
• No Fluid Spills: Foam components react inside a sealed system and harden instantly under the slab. There is no wet slurry or mud to run off into your garden or flowerbeds.

What happens to the remaining drill holes after lifting?

After foam injection is complete, injection ports are removed, and the 5/8-inch holes are patched flush with high-strength cement mortar.

Over time, exposure to weather, foot traffic, and natural weathering causes the small patch holes to blend seamlessly into the surrounding concrete surface.

How much time is needed until I can use my area again?

One of the greatest advantages of polyurethane foam lifting over mudjacking or full concrete replacement is rapid curing:

• Foot Traffic: Ready in 15 minutes. You can walk across your sidewalk or patio immediately after technicians clean up.
• Vehicle Parking: Ready in 30 minutes. You can park cars, trucks, or RVs on your lifted driveway or garage floor the very same day.
• Replacement Comparison: Freshly poured concrete requires 28 days to reach full design strength and 3–7 days before driving on it. Polyurethane foam cures to maximum strength within 15–30 minutes.

Is a building permit required for concrete lifting in Calgary?

No building permit is required for standard residential or commercial concrete lifting in Calgary.

Because polyurethane foam injection is classified as non-structural slab maintenance and repair (restoring an existing slab to its original grade without structural alterations), municipal building permits are not needed. If your project involves municipal right-of-way sidewalks or shared city property, our team handles all coordination requirements directly.

Ready to Restore Your Concrete?

Understanding how concrete lifting works makes it easy to see why thousands of property owners choose high-density foam over costly, messy demolition. It is faster, less intrusive, highly durable, and cost-effective.

• Explore how foam compares in price on our Concrete Lifting Cost Guide.
• Got specific questions about your slab? Visit our full Concrete Lifting FAQs.
• See the full range of applications on our Concrete Lifting Services Hub.