Concrete Driveway Repair: Cracks, Settling, and Resurfacing

Concrete Driveway Repair: What to Fix, When to Replace

Every concrete driveway will need some repair over its lifetime. The good news: many common problems are repairable without full replacement. The key is knowing which issues are cosmetic and fixable, which are early warning signs requiring professional attention, and which indicate it's time for a new driveway. This guide covers every type of concrete driveway repair, what it costs, and when replacement makes more financial sense.

Common Concrete Driveway Problems and Repair Options

Hairline Cracks

What it is: Very fine surface cracks (under 1/8 inch wide). Normal in virtually all concrete as it shrinks during curing and responds to thermal cycling. Usually not structural.

Repair approach: Fill with a liquid concrete crack filler or penetrating sealer. Clean the crack first with a wire brush or compressed air. Cost: $15–$40 DIY.

Urgency: Low, but fill before winter to prevent water infiltration and freeze-thaw widening.

Moderate Cracks (1/8 to 1/2 inch)

What it is: Visible cracks that have widened over time or developed from settling. May be structural or simply normal drying/thermal cracks.

Repair approach: Clean crack thoroughly; use a polyurethane caulk or concrete repair compound. For wider cracks, undercut the crack edges first (with an angle grinder or saw) to create a mechanical bond for the filler. Cost: $20–$100 DIY; $200–$500 professional patch.

Urgency: Moderate — fill before winter. Monitor for growth. If width is increasing or edges are displacing vertically, get a professional assessment.

Large or Growing Cracks (Over 1/2 inch)

What it is: Significant structural cracking that indicates sub-base failure, settling, tree root intrusion, or expansive soil movement.

Repair approach: Surface patching won't address the underlying cause. Require professional evaluation. Possible solutions: mudjacking (foam injection) to stabilize settled sections, sub-base repair, or section replacement.

Urgency: High — contact a professional concrete contractor for assessment.

Settled or Sunken Sections

What it is: One section of the driveway has sunk relative to adjacent sections, creating a height difference (trip hazard) and drainage problems.

Repair approach:

• Mudjacking (slabjacking): Holes are drilled through the slab; a slurry of cement, soil, and water is pumped under the slab to lift it back to level. Cost: $500–$1,500 for a typical settled section.
• Polyurethane foam injection: Expanding foam is injected through small holes to fill voids and lift the slab. Lighter-weight, more precise, but more expensive. Cost: $800–$2,500.
• Section replacement: Remove the settled section and replace with new concrete over properly compacted base material. Cost: $500–$2,000 per section depending on size.

Surface Spalling and Scaling

What it is: The surface layer flakes or pops off, exposing the aggregate below. Caused by freeze-thaw damage (often accelerated by deicers), poor curing, or low-quality concrete.

Repair approach:

• Minor scaling: Clean thoroughly and apply a concrete resurfacer ($1.50–$3/sq ft in materials for DIY; $3–$7/sq ft professional)
• Moderate to severe scaling: Apply a concrete overlay (1/4 to 3/8 inch thick) bonded to the existing slab. Professional cost: $3–$7/sq ft
• Widespread deep scaling: May indicate full replacement is more cost-effective

Staining (Oil, Rust, Leaf Tannins)

What it is: Surface discoloration from oil drips, rust from metal, organic material, or mineral deposits.

Repair approach:

• Oil: Concrete degreaser, stiff brush, rinse. For deep stains: poultice method with cat litter or degreasers
• Rust: Rust remover (oxalic acid-based). Cost: $10–$30 DIY
• General staining before resurfacing: Commercial concrete cleaner or muriatic acid solution (handle carefully)

Driveway Resurfacing: When to Resurface vs. Replace

Concrete resurfacing is cost-effective when:

• The slab is structurally sound (no settling, no active structural cracking)
• Surface is scaled, stained, or worn but not broken
• You want a fresh or decorative look without replacement cost

Resurfacing cost: $3–$7/sq ft professional; $1.50–$3/sq ft DIY materials
Typical two-car driveway (500 sq ft): $1,500–$3,500 professional

Resurfacing is NOT appropriate when:

• Multiple sections are settled or heaving
• Widespread structural cracking
• Sub-base failure is evident
• The slab is over 30–40 years old with extensive deterioration

In these cases, replacement is more cost-effective in the long run.

Repair vs. Replace: The Decision Framework

• Repair makes sense: If repair cost is under 30–40% of replacement cost AND the concrete is otherwise structurally sound
• Replace makes sense: If the driveway is over 25–30 years old with widespread problems, if settling or sub-base failure is extensive, or if you want a decorative upgrade
• Get a professional opinion: A qualified concrete contractor can assess whether your driveway is a good candidate for repair or resurfacing, or whether replacement is the better investment

Finding a Concrete Repair Specialist

Browse concrete repair contractors on ConcreteListings to find local professionals who specialize in assessment, repair, and resurfacing. Many contractors offer free estimates — get 2–3 opinions for any significant repair to ensure you're making the right decision.