Concrete Repair vs. Replace: How to Decide

Quick Verdict

Whether to repair or replace concrete in Oregon comes down to three things: the cause of the damage, how much of the slab is affected, and whether the base underneath is still sound. Surface problems on a stable slab — hairline cracks, light scaling, isolated chips — are repair candidates. Structural failure — wide moving cracks, settlement, heaving, or widespread alligator-style cracking — means the base has failed and a patch only buys time. The honest rule: repair surface damage on a sound base, replace when the base or a large share of the slab is gone. This guide gives you the thresholds so you can decide before you pay.

Start With the Cause, Not the Crack

A crack is a symptom. Before deciding anything, figure out why the concrete is failing, because the cause determines whether a repair will hold:

• Surface causes (shrinkage cracks, light scaling, oxidation) sit on top of a sound slab and are repairable.
• Structural causes (base failure, settlement, frost heave, overload) come from below and will defeat any surface fix.

A slab cracking from below keeps cracking no matter how well you patch the top. The concrete services overview covers how the base, joints, and reinforcement work together — and why their failure shows up as cracks.

The Decision Table

Cracks: When to Seal vs. Replace

Most cracks are repairable. Hairline and shrinkage cracks are cosmetic and just need sealing to keep water out. A single working crack on an otherwise sound slab can be routed and filled. The line is movement and offset: if the two sides of a crack have shifted up or down (a trip hazard), or the crack is widening season to season, the slab is moving and a fill will not hold. Our concrete crack repair guide covers which cracks respond to which method.

Surface Scaling and Spalling

Freeze-thaw and de-icers, especially east of the Cascades and in the Gorge, flake the top surface of concrete. If the flaking is shallow and the slab below is solid, the surface can often be resurfaced or overlaid rather than torn out — see concrete resurfacing & overlays. But once spalling goes deep enough to expose rebar or undermine the surface, repair gets less reliable and replacement is often the better value. The depth and extent decide — covered in concrete spalling repair.

Settlement and Heaving: Almost Always Replace

When a slab has settled (sunk) or heaved (lifted), the problem is the ground, not the concrete. On Oregon clay, this happens when the sub-grade was poorly prepped, drainage failed, or frost got under the slab. You cannot fix a moving base by patching the top. Some settled slabs can be lifted with mudjacking or foam injection if they are otherwise intact, but if the slab is also cracked through, replacement with proper base repair is the durable answer. Replacing without fixing the base just repeats the failure.

The "How Much Is Affected" Rule

Even with repairable damage, math matters. Patching one corner of a driveway is sensible. Patching a dozen spots across a slab costs nearly as much as replacement and leaves you with a patchwork that keeps failing. A rough rule: when more than roughly a quarter to a third of a slab needs repair, or when repairs would be ongoing, replacement is usually the better long-term value — and it lets you fix the base and drainage at once.

Current Market Reality

Industry Baseline Range: crack sealing and small patches commonly run in the range of a few hundred dollars, resurfacing an intact slab runs more, and full removal-and-replace runs in the range of $8 to $16-plus per square foot installed+. These are industry baseline ranges for planning only — actual pricing depends on lot size, access, condition, and current market conditions. Get a site-specific quote. Because replacement also resets the base and drainage, it often costs less over ten years than repeated repairs on a failing slab.

The Bottom Line

Repair surface damage on a sound base; replace when the base has failed, the slab is moving, or too much of it is gone. Diagnose the cause first — a patch over a structural problem is money thrown away. For the broader concrete picture, start at our concrete services overview.

Cojo is CCB Licensed and Insured, based in Hood River, and assesses concrete honestly across the valley, the Gorge, and the I-5 corridor. Explore our concrete services and request a quote — we will tell you whether your slab needs a repair or a replacement, and why.