Concrete Repair vs. Replacement: A Decision Matrix for Cracks, Spalling, and Settlement

When to patch, when to mud-jack, when to grind, and when to demo and re-pour. A field-tested framework for deciding what to do with failing concrete.

Start with cause, not symptom

Repairing a symptom without addressing the cause guarantees the problem comes back. A cracked driveway over a failing subgrade will crack again within a year of any patch. Subgrade fundamentals.

Diagnose first: is the issue surface-level (wear, light scaling, cosmetic crack) or structural (settlement, heaving, working cracks that grow seasonally)?

Surface repairs that work

Hairline cracks: clean, fill with a polyurethane crack sealer. $2-$5 per linear foot. Lasts 5-10 years.

Light scaling and pop-outs: grind the surface, apply a polymer-modified resurfacer 1/4 to 1/2 inch thick. $4-$8 per sq ft.

Worn or stained slab: diamond grind and densify, optionally stain for color. Common on garages and shops.

Structural repairs

Settled slab with intact concrete: mud-jacking or polyurethane foam jacking lifts the slab back to grade. $4-$10 per sq ft. Best on sidewalks, driveways, and pool decks where the slab is structurally sound but settled.

Heaved slab: usually frost or expansive soil. Grind the heaved edge if minor; demo and re-pour with proper subgrade if major.

Working crack with offset (one side higher than the other): structural movement. Stitch with rebar dowels and epoxy, or demo the affected section. May indicate foundation movement.

When to demo and re-pour

Multiple cracks across the slab, especially with offsets or width over 1/4 inch.

Deep spalling exposing rebar across more than 10% of the surface.

Slab thickness less than the use requires (4-inch slab being driven on by trucks).

Repair estimate exceeds 50-60% of replacement cost.

Demolition cost for a typical driveway: $2-$4 per sq ft. Re-pour cost: $9-$14 per sq ft. Full pricing in the driveway cost guide.

How to write a repair-or-replace bid request

Photograph every visible defect with a tape measure for scale.

Note the age of the slab and any history (additions, drainage changes, vehicle weight changes).

Ask the contractor for both options, repair scope with expected lifespan, and full replacement with warranty.

Bedrock provides side-by-side bids on repair and replacement scopes for every assessment we run, request an evaluation.

Frequently asked questions

How long do concrete repairs last?

Crack sealers: 5-10 years. Resurfacers: 10-20 years on sound substrate. Mud-jacking: permanent if the cause of settling is fixed.

Can I resurface my driveway instead of replacing it?

Only if the substrate is structurally sound, no major cracks, no settlement, no rebar exposure. Otherwise, replace.

Is foam jacking better than mud jacking?

Faster set, lighter weight (less risk of re-settling), smaller injection holes. Costs 20-40% more.