Polyurethane Foam Lifts Sinking Slabs Without Tearing Up Your Driveway.

Polyurethane foam injection runs $5 to $25 per square foot of slab lifted in our region, depending on void depth, lift height, and access. A typical sunken driveway section (200 to 400 square feet) commonly falls between $1,500 and $4,500. Larger void fills, deep settlement, or restricted access can push higher. Written estimate after on-site inspection reflects your scope.

Closed-cell polyurethane foam is inert, hydrophobic, and rated for 50+ year service life in soil. Epp Foundation Repair backs the install with a 5-year written warranty against re-settlement at the treated area. If the lifted section drops below tolerance within the warranty period from a covered cause, Epp re-injects at no charge. Warranty documentation stays with the home for the next owner.

No. A sunken slab will not lift itself, and the void underneath grows over time. Untreated, the symptoms get worse: the tripping edge tears at shoes, the negative slope channels water toward the house instead of away, the void enlarges as soil continues to wash or settle, and adjacent slab sections start to crack from the lateral pull. A $2,000 foam injection today is materially cheaper than a $6,000 slab replacement two years from now after the concrete has cracked beyond repair.

Both lift slabs. The differences are weight, hole size, and cure time. Foam is roughly 4 pounds per cubic foot. Light enough that it doesn't re-stress the failing soil column. Cementitious slurry (mudjacking) is roughly 100 pounds per cubic foot. Foam ports are 5/8-inch; mudjacking holes are 1 to 2 inches. Foam cures in 15 minutes; slurry cures in 24 to 48 hours. For most residential driveways, sidewalks, and pool decks, foam is the cleaner, faster, lighter-load option. Mudjacking still wins on very large void fills where material cost dominates.

Properly executed lifts almost never crack the slab. Foam injection raises the slab in fractional increments distributed across multiple ports. So the upward force is spread evenly. The risk of cracking goes up sharply on slabs that are already structurally compromised: hairline cracks running corner to corner, slabs broken into multiple pieces, or slabs where rebar has rusted and lost section. During the inspection, Epp identifies slabs that are too far gone for lift and recommends replacement instead.

Surface lift fills the void directly under the slab, but it doesn't address the soil weakness several feet down. Which is often where loess hydroconsolidation or clay shrinkage actually originated. Dave Epp's crews target the mid-soil zone with deeper injection ports on settlement that traces to soil failure at depth. The deeper injection densifies the soil column, not just the surface void. Which is the difference between a slab that holds for 5 years and one that holds for 25.

Let's take the first step toward a healthy home.

A local specialist will inspect your foundation, walk you through the findings, and send a clear estimate. no cost, no pressure.