Foam Injection & Slab Lifting Installer in Durham, NC

Polyurethane foam injection is the modern replacement for mudjacking on any sunken concrete slab that is still structurally sound. Instead of pumping heavy slurry through 2-inch holes, a two-part expanding polyurethane resin is injected through 3/8-inch to 5/8-inch ports drilled in the slab. The resin reacts and expands within 15 seconds, filling every void underneath, compacting the base material, and lifting the slab back to grade in controlled lifts. The foam cures in about 15 minutes, is walkable immediately, and drivable in 4 to 8 hours. It weighs roughly 4 pounds per cubic foot compared to 100-plus for mudjack slurry, will not wash out with groundwater, will not shrink over years, and will not add settlement load to soil that already failed once.

Local Concrete Contractor lifts residential and light commercial slabs across the entire state — sunken sidewalk sections at trip-hazard grade differentials, driveway panels that have dropped an inch or two at the apron, patio slabs that pitched toward the house, garage floors that dropped at the door threshold, pool decks that settled next to the coping, and interior slabs on grade where a plumbing leak or clay-soil shrink washed out the base. Every job starts with a walk to confirm the slab is a lifting candidate (not cracked to the point that lifting will fracture it further), a written scope with hole pattern, lift target in inches, foam volume estimate, and a fixed price. No deposit, no vague scope on the invoice, and no upcharge if we find more voids than expected — the number on the sheet is the number you pay.

What We Lift and What We Won't

Foam injection is not a fix for every slab problem. It is the right tool for a slab that has dropped because the base under it settled, washed out, or compressed — not for a slab that has cracked into pieces or spalled through the top mat of reinforcement.

• Sunken sidewalk sections with a lip greater than 1/4 inch (ADA trip-hazard threshold) — typically 1 to 3 inch lifts across 1 to 3 panels
• Driveway panels dropped at the apron, mid-run, or against the garage foundation — typically 1 to 4 inch lifts, single panels or full drives
• Patio slabs that pitched back toward the house — corrected slope typically 1 to 2 inches over 8 to 12 feet
• Garage floors that dropped at the overhead door threshold or along the foundation wall — 1 to 3 inch lifts
• Pool deck slabs that settled next to the coping or at fence-post lines — careful lifts to reset slope without pushing water into the pool coping
• Interior slabs on grade after a plumbing leak, water heater burst, or clay-soil shrink event — done with low-expansion foam and moisture control
• Void fill under foundations, footings, and slab edges where soil has washed out but the concrete has not yet dropped — stabilization, not lifting

Slabs we will not foam-lift: any slab cracked into 4 or more pieces, any slab with significant spalling through the top mat, any slab where the base failure is ongoing (active plumbing leak not repaired, downspout still discharging under the slab, sinkhole or subsidence-zone soil). On those, the honest answer is remove and repour, and we will say so on the site visit before you spend money on a lift that will not hold.

Foam vs. Mudjacking vs. Replacement — Straight Numbers

Homeowners typically compare three options for a sunken slab: polyurethane foam injection, traditional mudjacking with a cement-and-limestone slurry, and full slab replacement. The right choice depends on slab condition, timeline, and budget.

Polyurethane foam — 3/8 to 5/8 inch injection ports, foam expands and cures in 15 minutes, drivable in 4 to 8 hours, weighs 4 lb/ft³, will not wash out or shrink. Typical residential lift job is 1 to 2 hours on site. Cost premium over mudjacking is 20-40%, but the slab is back in service same day and the lift holds long-term.

Mudjacking — 2-inch injection holes, cement slurry pumped under the slab to raise it, cures over 24-48 hours, weighs 100+ lb/ft³. Cheaper upfront but the slurry can shrink 5-15% as it dries, wash out with groundwater, and add settlement weight to soil that already failed. Holes leave visible 2-inch patches. Still viable for exterior slabs where cost is the only factor and long-term hold is not critical.

Full replacement — saw-cut, demo, haul-off, re-pour with proper base build. Typical cost is 5 to 10 times the lift price. Required when the slab is cracked beyond salvage or when a lift will not correct the underlying grade problem. Timeline is 3 to 7 days including cure. This is the honest recommendation on slabs beyond the lifting envelope.

When we walk a site we give you the lift number, the mudjack number if we still do it on that job, and the replacement number, so you can decide with real numbers instead of a sales pitch. On some jobs — heavily cracked slabs, marginal base, decorative slabs where the finish matters more than the structure — the honest recommendation is replacement, and we will say so.