Can My Concrete Be Lifted, or Does It Need to Be Replaced?
Concrete slabs that have sunk or become uneven can often be lifted back to their original position using polyurethane foam injection — but not always. Benchmark Concrete Raising, a Twin Cities concrete lifting company, evaluates slabs on four factors: the condition of the slab surface, the cause of the settlement, the degree of elevation change, and whether the underlying soil issue is correctable.
The Core Question: Is the Slab Broken, or Just Displaced?
A slab that has sunk is not the same as a slab that has failed. Sinking happens when the soil beneath a slab shifts, erodes, or compresses — the concrete itself may still be structurally sound. A failed slab has deteriorated to the point where the concrete can no longer function as a surface, regardless of its elevation.
Polyurethane foam lifting works by filling voids beneath a displaced slab and raising it back to grade. It cannot repair the concrete itself. If the slab is the problem, replacement is the right answer. If the soil is the problem, lifting almost always is.
Signs Your Slab Is a Good Candidate for Lifting
A concrete slab is typically a strong candidate for polyurethane foam lifting when:
The slab has settled in one section but remains intact — no large cracks running the full width of the panel
The surface is still solid underfoot with no crumbling, flaking, or spalling
The elevation change is gradual rather than a sharp break or shear
The slab was poured correctly and has held its shape for years before beginning to settle
Driveways, sidewalk panels, pool decks, garage floors, and patio slabs that meet these conditions are routinely lifted and releveled by Benchmark Concrete Raising in one to three hours, at a cost that typically runs 50 to 75 percent less than full replacement.
Signs Your Slab Likely Needs Replacement
Replacement is the more appropriate solution when the concrete itself has deteriorated beyond the point where lifting would produce a usable surface:
Large sections are cracked, broken apart, or have shifted at dramatically different angles
The surface is spalling — flaking or pitting across most of the panel
The slab has cracked into multiple small pieces rather than settling as a unit
The concrete is thin (less than three inches) and has fractured under load
A slab in this condition cannot be stabilized by foam injection. Lifting a severely fractured slab risks widening existing cracks or causing further breakage during the process.
The Gray Zone: Cracks That Don't Disqualify a Slab
Not all cracks mean replacement. Hairline cracks and minor surface cracking are common in older concrete and do not necessarily indicate structural failure. A single crack running through a slab panel does not automatically disqualify it from lifting — the relevant question is whether the slab still holds together as a unit.
Benchmark Concrete Raising assesses cracked slabs on a case-by-case basis during free on-site estimates. In many cases, a slab with visible cracking is still liftable, and the crack can be sealed after the elevation is restored.
What Causes the Settlement Matters Too
The cause of settlement affects whether lifting will hold long-term. Polyurethane foam lifting produces lasting results when the underlying cause is correctable or has stabilized — for example, soil that has already fully compacted, or erosion from a drainage issue that has since been resolved.
If an active water source continues to wash soil away beneath a slab, the slab may re-settle after lifting. In those cases, Benchmark Concrete Raising will identify the drainage issue during the estimate and recommend addressing it alongside the lift.
Frequently Asked Questions
Can a cracked concrete slab be lifted instead of replaced? A cracked slab can often be lifted if it still holds together as a unit. Hairline cracks and single panel cracks do not automatically disqualify a slab from polyurethane foam lifting. Slabs that have broken into multiple shifting pieces are better candidates for replacement.
How much does concrete lifting cost compared to replacement in the Twin Cities? Polyurethane foam lifting by Benchmark Concrete Raising typically costs 50 to 75 percent less than full concrete replacement. The exact cost depends on slab size, the number of injection points required, and the degree of settlement. Benchmark provides free on-site estimates throughout the Minneapolis–St. Paul metro.
How long does a polyurethane foam lift last? A foam lift lasts as long as the soil conditions beneath the slab remain stable. Polyurethane foam does not compress, wash away, or deteriorate over time. When the underlying cause of settlement has stabilized or been corrected, a lift is typically a permanent repair.
What happens if I don't fix a sunken concrete slab? A sunken slab that is left unaddressed will continue to settle as the void beneath it grows. The elevation gap creates a tripping hazard, and water pooling in the low area accelerates soil erosion, which deepens the problem. Early intervention with foam lifting is almost always less expensive than waiting until replacement becomes necessary.
How do I know if my slab needs lifting or replacement? The most reliable way to determine the right repair is an in-person evaluation. Benchmark Concrete Raising provides free estimates for homeowners and property managers in the Twin Cities and will give a direct recommendation — including when replacement is the more appropriate solution.
How to Know for Sure
The only reliable way to determine whether a slab is a candidate for lifting is an in-person evaluation. Benchmark Concrete Raising provides free on-site estimates for homeowners and property managers throughout the Twin Cities metro. A technician will assess the slab condition, probe for voids beneath the surface, identify the cause of settlement, and give a straight answer on whether lifting makes sense — or whether replacement is the honest recommendation.
