Polyurethane foam being injected under sunken concrete slab for lifting and leveling

Lift Sunken Concrete
with Polyurethane Foam

Two-component expanding polyurethane foam injected beneath sunken slabs — precise, fast, and a fraction of the cost of mudjacking or full replacement. Oak Ridge supplies the foam and the equipment.

~2 lb
Foam density vs.
100 lb/cu ft mudjacking clay
15 min
Return to traffic
after foam injection
¾″ hole
Injection port size —
minimal surface disruption
1984
Oak Ridge supplying
foam & equipment

What Is Polyurethane Concrete Lifting?

Polyurethane concrete lifting — also called polyjacking, foam lifting, or slab jacking with foam — is a method of raising sunken, settled, or uneven concrete slabs without demolition. A two-component expanding polyurethane foam is injected through small ports drilled in the slab. As the A and B components mix and react, the foam expands under controlled pressure, filling voids and raising the slab back to its original grade.

The reaction is fast and highly controllable. Experienced operators can achieve lift precision measured in fractions of an inch by regulating injection volume and monitoring grade in real time. Once the foam cures — typically within minutes — it forms a rigid, closed-cell structure that is waterproof, dimensionally stable, and highly resistant to soil wash-out.

Compared to traditional mudjacking (pumping a cement-sand-water slurry beneath slabs), polyurethane foam offers dramatic advantages in weight, cure time, and long-term performance. Compared to full slab replacement, poly lifting can cost 50–75% less and eliminates weeks of disruption.

1
Drill small injection ports

Technicians drill ¾" holes through the slab at strategic locations above voids or settled areas. Ports are spaced to ensure foam coverage across the full lift zone.

2
Inject two-component foam

An IPM or PMC proportioner pumps equal volumes of the A (isocyanate) and B (polyol blend) components at high pressure through heated hoses to a mix gun inserted at the port. The components react on contact.

3
Foam expands and lifts

The expanding foam fills voids, compacts loose subbase material, and generates upward pressure that raises the slab. Operators monitor grade and stop injection when the target elevation is reached.

4
Patch ports and return to service

Injection ports are patched with non-shrink grout or caulk. The slab is ready for foot and vehicle traffic within 15–30 minutes. No waiting for curing concrete, no barricades for days.

Before & After: Polyurethane Concrete Lifting

Sunken driveways, settled warehouse slabs, and tripping-hazard sidewalks lifted back to grade — without tearing out and replacing the concrete.

Sunken concrete driveway before polyurethane foam lifting — significant settlement visible
BEFORE
Settled driveway slab
Concrete driveway after polyurethane foam lifting — fully leveled and flush
AFTER
Lifted and leveled
Uneven concrete slab with visible drop before poly lifting repair
BEFORE
Uneven panel drop
Concrete slab fully leveled after polyurethane foam injection
AFTER
Grade restored precisely
Settled concrete before foam slab jacking — trip hazard at panel joint
BEFORE
Trip-hazard panel joint
Panel joints flush after polyurethane foam concrete lifting — hazard eliminated
AFTER
Hazard eliminated
Professional concrete lifting crew using polyurethane foam injection equipment on large slab

Finished Result

Same-day service. No concrete removal. Back in use within the hour.

Applications for Polyurethane Slab Lifting

Any concrete surface that has settled, sunken, or become uneven is a candidate for polyurethane foam lifting — residential, commercial, municipal, or industrial.

Residential Driveways

Garage aprons, driveway panels, and approach slabs that have dropped due to soil erosion, frost heave, or compaction are common targets. Work is completed in hours — not days — with no driveway replacement needed.

Sidewalks & Pathways

Uneven sidewalk panels create trip hazards and ADA compliance issues. Foam lifting restores flush joints quickly, allowing municipalities and property owners to address liability concerns without full sidewalk replacement.

Garage Floors

Garage floor slabs that have dropped at the perimeter or cracked in the center are often caused by sub-base voids. Foam fills those voids and lifts the slab without removing vehicles, equipment, or floor coatings.

Warehouse & Industrial Floors

Forklift traffic causes slab fatigue and soil consolidation. Panel differential of even ½" can damage forklifts and product. Foam lifting levels panels overnight — operations resume the next shift without extended downtime.

Pool Decks

Pool deck slabs settle toward the pool structure as backfill compacts over time. Foam lifting raises settled panels without disturbing existing tile, coping, or waterline finishes. The waterproof foam also helps reduce future water infiltration under the slab.

Highway & Airport Pavement

DOTs use polyurethane slab stabilization and lifting on jointed concrete pavement to correct panel faulting — the differential displacement at transverse joints that causes ride roughness and accelerates pavement fatigue. Lane closures are measured in hours.

Bridge Approaches & Ramps

The "bump at the bridge" — settlement of approach slabs relative to the bridge deck — is one of the most common highway maintenance problems. Polyurethane foam injection stabilizes the sub-base and lifts approach slabs efficiently, with no lane closure stretching over days.

Parking Lots & Loading Docks

Concrete parking lot panels and loading dock aprons subjected to repeated heavy truck loading can settle unevenly. Foam lifting addresses settled dock aprons and panels without tearing up the entire lot — sections can be done overnight to keep the facility operational.

Polyurethane Foam vs. Mudjacking

Both methods aim to lift sunken concrete without replacing it — but the materials and results are very different.

Factor
Polyurethane Foam
Mudjacking (Cement Slurry)
Material Weight ~2 lb/cu ft
Near-weightless — no added load on sub-base
~100–120 lb/cu ft
Adds significant weight; can accelerate future settlement
Cure / Return to Service 15–30 minutes
Same-day traffic restored
24–72+ hours
Extended closures required
Hole Size ¾″ diameter
Minimal surface disruption
1½″–2″ diameter
Larger, more visible patches
Water Resistance Waterproof
Closed-cell foam does not absorb water; resists wash-out
Water-susceptible
Slurry can erode and wash out over time
Lift Precision Fraction-of-inch control
Operator adjusts in real time by volume and location
Less precise
Fluid slurry harder to control; over-lift risk
Long-Term Stability Dimensionally stable
Rigid closed-cell foam does not shrink, settle, or biodegrade
Variable
Organic material in slurry can decompose over time
Equipment Needed Portable proportioner
Compact unit fits in a van or small trailer
Large mixing trucks
Heavier, louder, more intrusive on residential jobs

Foam vs. replacement: polyurethane concrete lifting typically costs 50–75% less than full slab removal and replacement, with a fraction of the disruption time.

Oak Ridge 2.8 lb high-density polyurethane concrete lifting foam in use on settled slab project

2.8 lb High-Density Concrete Lifting & Leveling Foam

Oak Ridge Foam & Coating Systems manufactures and supplies a purpose-formulated 2.8 lb/cu ft high-density two-component polyurethane foam for concrete lifting and slab stabilization applications. This is not a general-purpose spray foam — it is engineered specifically for the controlled, high-pressure injection environment required for poly lifting work.

Nominal 2.8 lb/cu ft density — high enough to support slab loads and distribute pressure evenly, light enough to add negligible weight to the sub-base
Consistent cream time and rise — formulated for predictable expansion at field temperatures, giving operators reliable control
Closed-cell structure — waterproof and vapor-resistant once cured; resists wash-out from groundwater or drainage intrusion
Excellent compressive strength — rated to support vehicle loads and industrial equipment; ideal for warehouse floors and highway applications
1:1 mix ratio by volume — compatible with standard poly lifting proportioners; no special ratio guns required
Available in drum and tote quantities — call Oak Ridge to discuss volume pricing and delivery to your region

The Right Proportioner for Concrete Lifting Work

Polyurethane concrete lifting requires a heated, high-pressure plural-component proportioner — the same basic technology used for spray foam and polyurea, adapted for controlled injection through small-diameter ports.

IPM Proportioning Machines

Integrated Proportioning Machines for controlled-volume lifting

IPM proportioners are widely used in the concrete lifting industry because of their precise volume control and compact form factor. These machines meter equal volumes of A and B components at precisely regulated pressure and temperature, then deliver the mixed foam through heated hoses to a dispensing gun at the injection port. Oak Ridge is an authorized supplier of IPM equipment — including proportioners, heated hose sets, and accessories designed for poly lifting applications.

  • Compact — fits in a service van or small trailer
  • Variable output for precision injection control
  • Heated A and B lines to maintain chemistry temperature
  • Suitable for both residential and commercial-scale jobs

PMC Proportioning Machines

High-output machines for large commercial projects

PMC (Polyurethane Machinery Corporation) proportioners are the industry benchmark for high-pressure, heated plural-component dispensing. Used extensively in spray foam roofing and polyurea coating applications, PMC machines are equally well-suited for concrete lifting when paired with the right mix guns and injection port accessories. Their proven reliability, wide operating range, and robust heated hose systems make them a strong choice for contractors who want a single machine capable of poly lifting, spray foam, and coatings work. Oak Ridge supplies PMC proportioners and can help configure a machine package for your poly lifting operation.

  • High-pressure output for consistent foam injection
  • Multi-purpose — also handles spray foam and polyurea
  • Proven reliability across thousands of field hours
  • Full parts and service support through Oak Ridge

Starting a Poly Lifting Business? Oak Ridge Can Set You Up.

Whether you're adding concrete lifting to an existing spray foam or foundation repair operation, or starting a dedicated poly lifting company, Oak Ridge can supply the foam chemistry, proportioner, hoses, guns, and injection port accessories as a complete package — along with the technical support to get your first jobs done right.

Supplying Concrete Lifting Foam Since 1984

Oak Ridge Foam & Coating Systems, Inc. has been manufacturing and distributing two-component polyurethane foam systems from Green Lake, Wisconsin since 1984. We're not a distributor reselling someone else's chemistry — we're a manufacturer who controls the formulation, the production process, and the product quality that goes out our door.

For concrete lifting contractors, that means you get direct access to the foam chemist, not a customer service representative reading from a spec sheet. When your foam isn't behaving as expected on a cold morning job or a humid summer slab, you need real answers — and Oak Ridge can provide them.

40+
Years manufacturing foam systems
Manufacturer
Direct — not a reseller
WI-Based
Green Lake, WI — ships nationwide
Full Line
Foam + equipment + support
Consistent formulation batch to batch

Every drum of concrete lifting foam from Oak Ridge is manufactured to tight tolerances. You're not getting rework or off-spec material — just the same chemistry your crews can rely on job after job.

Technical support from people who know foam

Call us at 800-625-9577 with a field question and you'll reach a real person who understands two-component chemistry, machine settings, and job conditions — not a voicemail system.

Ships nationwide from Green Lake, WI

We ship drums and totes of concrete lifting foam across the country. Whether you need a single set to try or a pallet order to stock a busy season, Oak Ridge can accommodate your volume.

Concrete Lifting Foam — Technical FAQ

What density foam is used for concrete lifting?
The most common density for concrete lifting applications is 2.0–3.0 lb/cu ft. Oak Ridge's concrete lifting foam is formulated at a nominal 2.8 lb/cu ft — dense enough to provide the compressive strength needed to support slab and vehicle loads, while remaining light enough to add negligible weight to the sub-base. Using lower-density foam (1.5–2.0 lb) risks insufficient compressive strength under heavy load applications like warehouse floors or highway pavement.
What pressure and temperature does poly lifting foam require?
Poly lifting foam is typically processed at 800–1,200 psi dynamic pressure and A/B component temperatures of 120–140°F, depending on the specific system and ambient conditions. Proper heated hose temperature is critical — cold B component (polyol blend) increases viscosity and can result in poor mix quality and off-ratio material. Your proportioner's temperature settings should be verified at the start of every job, especially in cold weather.
How much foam does it take to lift a 10×10 driveway panel by 1 inch?
A rough calculation: lifting a 10'×10' (100 sq ft) slab 1 inch requires approximately 100 sq ft × 1/12 ft = 8.3 cubic feet of void fill — but at 15–20× expansion, that corresponds to less than half a gallon of mixed liquid foam. In practice, actual consumption depends on existing voids, sub-base compaction, and whether the foam has somewhere to go laterally. Most residential panel lifts use 1–3 gallons of mixed material; larger commercial slabs may use 5–15+ gallons per panel.
Does polyurethane lifting foam cause slabs to crack?
Over-injection is the primary cause of cracking during foam lifting. An experienced operator stops injection before over-pressuring the slab — the slab tells you when it's at grade. Pre-existing cracks do not preclude lifting, but indicate the slab's structural limits and require careful technique. Slabs in very poor condition (multiple full-depth cracks, rocking panels) may be better candidates for replacement than lifting.
Is polyurethane concrete foam the same as spray foam insulation?
They share the same basic two-component polyurethane chemistry, but concrete lifting foam is formulated very differently. Spray foam insulation (closed-cell roofing or wall foam) is typically 1.8–3.0 lb/cu ft and engineered for adhesion and thermal performance. Concrete lifting foam is specifically formulated for controlled void-fill and slab support — with a reaction profile, viscosity, and expansion behavior suited to injection through small ports under a concrete slab. Do not substitute general spray foam insulation material for concrete lifting applications.
Will polyurethane foam hold up under freezing temperatures after installation?
Yes. Fully cured closed-cell polyurethane foam is dimensionally stable through the full range of soil temperature cycles. It does not absorb water and therefore does not heave or crack due to freeze-thaw cycles the way wet clay fill can. This is one of the key long-term advantages of foam over mudjacking slurry, especially in upper Midwest climates with severe frost cycles.

Ready to add concrete lifting
to your service line?

Oak Ridge Foam & Coating Systems supplies 2.8 lb high-density concrete lifting foam, IPM and PMC proportioning equipment, and the field expertise to help you start — or scale — a polyurethane concrete lifting operation. We've been in the foam business since 1984 and we'll help you get the right system for your jobs.

Call us at 800-625-9577 or toll-free 800-625-9577 — 575 Commercial Ave, Green Lake, WI 54941