Short answer: In the short term, repairing is usually cheaper for small, non-moving defects (hairline cracks, shallow scaling, minor settlement). In the long term, replacement can be cheaper when the slab has base failure, active movement, or widespread weak paste—because repairs won’t last through Kansas City’s heat, wind, and freeze–thaw cycles. The lowest total cost comes from matching the method to the cause and building in proper jointing, drainage, support, and curing. If you want help assessing your slab, start with our concrete repair team.
Why “Cheaper” Depends on Cause, Extent, and Kansas City Conditions
Concrete doesn’t fail only because of compressive strength; it fails at details: trapped water at edges, weak or uneven support, late joint cuts, and under-cured paste. In Kansas City, hot windy summers accelerate evaporation and crusting, while winters bring freeze–thaw and deicers that scale any porous surface. Clay-influenced soils swell when wet and shrink when dry, stressing edges and joints. The same cosmetic crack can be a cheap repair—or a sign of expensive movement—depending on context.
- Cause: Drying shrinkage vs. settlement vs. lateral pressure vs. surface scaling. Extent: One hairline vs. many random cracks; one corner vs. panels across a patio or drive. Exposure: Exterior slabs exposed to deicers and freeze–thaw require air-entrainment, tight curing, and often thicker sections. Support: Voids and soft spots cause rocking panels and joint pumping; without support correction, repairs fail early.
Quick Cost Reality (Typical Tendencies, Not Bids)
ScopeWhen It’s AppropriateTendency (KC)Longevity Notes Clean & seal hairline cracks Static hairlines within good joint layout Lower cost per crack Blocks water/chlorides; cosmetic; monitor seasonally Epoxy injection (static structural crack) Non-moving cracks ≥ 1/16", no offset Moderate per crack Restores tensile continuity; honor line in joint plan Slabjacking/polyjacking Voids, sunken panels, but slab otherwise sound $/ft² range; poly higher than cement grout Excellent if water cause is fixed; fast return to service Polymer-modified resurfacer Shallow scaling/spalls on sound substrate Lower than overlay or R&R Demands CSP prep, joint fidelity, diligent curing Bonded overlay (≥ 1½–2" exterior) Sound substrate; widespread wear Mid-range Behaves like new wearing course; honor joints; cure/seal Remove & replace (R&R) Base failure; active movement; weak paste everywhere Highest up front Lowest risk of callbacks if base, joints, and curing are correctedNote: Exact prices vary with area, access, demolition, saw-cutting, restoration, permits, and finish choice. Use line-item bids for apples-to-apples comparison.
Decision Tree: Repair, Overlay, or Replace?
Is the slab moving? (Seasonal crack width change, rocking panels, joint pumping.)• Yes: Stabilize support (slabjack/foam) or R&R. Overlays without support correction will reflect and fail.
• No: Go to Step 2. Is the substrate sound? (No hollow spots/delamination.)
• No: R&R or unbonded topping if elevation allows. Is water managed? (Downspouts, grading, irrigation.)
• No: Fix water first. Any repair will be temporary otherwise.
• Yes: Proceed with selected method and plan jointing/curing per season.
Lifecycle Cost Comparison (5–10 Years)
ApproachUp-Front CostRisk of ReworkTypical Triggers for FailureBest Use Clean & seal Low Low–Medium Deicers, UV, crack movement Static hairlines; routine maintenance Epoxy injection Moderate Low (if truly static) Hidden movement; poor surface prep Non-moving structural cracks Slabjacking / polyjacking Moderate Low–Medium Repeat saturation; uncontrolled downspouts Lost support under otherwise sound slabs Resurfacer (thin) Low–Moderate Medium Inadequate CSP; late joints; poor curing Light scaling; cosmetic renewal Bonded overlay Moderate Low–Medium Ignoring joints; moisture traps; weak substrate Sound base with worn surface Remove & replace High Low Rare when details are corrected Base failure; active movement; pervasive weaknessRepair Options in Detail (When They’re Truly Cheaper)
1) Clean & Seal Hairline Cracks
For static hairlines inside a proper joint plan, sealing keeps water and chlorides out and prevents freeze–thaw damage. It’s fast and inexpensive. It won’t fix movement, but it does extend service life with minimal cost.
2) Epoxy Injection (Static Structural Cracks)
Route, clean, port, and inject low-viscosity epoxy to weld concrete across a non-moving crack. Finish by grinding flush, then honor the crack with a joint so thermal/drying movement occurs where you choose—not through your repair.
3) Slabjacking / Polyjacking (Support Restoration)
If joints pump or panels rock, repair the support. Cement grout (slabjacking) is cost-effective; polyurethane (polyjacking) costs more but uses tiny holes, cures fast, and adds less weight. Both are durable if you fix the cause (downspouts, poor grade, plumbing leaks). We handle both methods in the KC metro—see repair options.
4) Polymer-Modified Resurfacer
Great for uniform appearance and light wear, provided you shot-blast or grind to an ICRI CSP (often 3–5), place over sound concrete, align jointing, and cure immediately. It’s a lower-cost way to refresh without the height of an overlay.
5) Bonded Concrete Overlay (≥ 1½–2" for Exterior)
When the substrate is sound but tired, a bonded overlay creates a new exterior-grade wearing surface. It’s cheaper than R&R and longer-lived than a thin resurfacer—if you align joints directly above the substrate and cure aggressively. For driveways that need a new wearing course, explore driveway overlays.
When Replacement Is Cheaper Overall
concrete driveways- Active movement: Cracks open/close seasonally, panels shift, or edges chip repeatedly—signals base issues. Pervasive weak paste: Large areas dusting or delaminated; bonding anything to it is risky. Elevation conflicts: Overlays can’t fit thresholds or drainage; R&R resets elevations. Hidden voids or utilities: If large areas lack support, piecemeal lifting can exceed the cost of R&R.
Best-Practice R&R Spec for Kansas City Exterior Slabs
- Base: 6–8" compacted dense-grade aggregate (DGA) over geotextile on pumping clays; full thickness to the edge—no feathering. Slab: 5–6" exterior mix, air-entrained (~5–7%) at low water–cement ratio, water reducer mandatory; light retarder in heat, non-chloride accelerator in cold. Reinforcement: #3/#4 rebar at 18–24" each way on chairs; dowels at garage thresholds for load transfer. Joints: Spacing ≈ 24–36× thickness (inches); early-entry saw cuts the same day in hot weather; intercept re-entrant corners. Curing & sealing: Membrane-forming curing compound immediately after finishing and after saw-cuts; later, penetrating silane/siloxane; avoid deicers the first winter.
KC Weather Playbooks (To Protect Your Spend)
Summer (Hot + Windy)
- Sunrise placement; shade/windbreaks; fog the air (not the surface). Use water reducer instead of adding water; consider a light retarder. Cut joints early with an early-entry saw; cure immediately after finishing and post-cuts.
Shoulder Seasons (October/April)
- Place on non-frozen subgrade; warmed mix water; non-chloride accelerator as needed. Protect with insulated blankets if nights approach 40°F; watch for dew before sealing.
Case Studies (Kansas City Metro)
1) Patios with Shallow Scaling → Resurfacer Wins
Situation: Two patios with light scaling and intact bases. Action: Shot-blast to CSP 4, route/clean hairlines, polymer-modified resurfacer, joint alignment, immediate curing, penetrating sealer after dry-back. Outcome: Crisp broom texture after three winters; resurfacer cost much less than R&R.
2) Rocking Driveway Panels → Support First
Situation: Driveway slabs rocked at joints; gutter dumped at edge. Action: Extend downspouts 10 ft, regrade soil, polyjack low panels, seal joints. Outcome: No pumping the next winter; total spend below overlay or R&R.
3) Widespread Delamination → R&R Cheaper Long-Term
Situation: Garage apron and approach scaled and dusted extensively. Action: Remove and replace with 6" air-entrained slab over 8" DGA; #4 at 18" o.c.; dowels at threshold; early-entry joints; curing/sealer schedule. Outcome: Higher up-front cost but five-year lifecycle cost lowest; no threshold chipping.
Comparing Bids (Make “Cheaper” Real, Not Risky)
Line-item pricing: Request per-unit costs (per crack, per joint ft, per ft² overlay, per pier/lift if needed) and separate line items for prep, jointing, curing, sealing, and restoration. Scope clarity: Insist on a water management plan (downspouts/grade); without it, any bargain is a mirage. Jointing plan: Ask for a sketch showing joint spacing and how re-entrant corners are intercepted; require same-day early-entry cuts in hot weather. Mix design & season plan: Exterior = air-entrained, low w/c, water reducer; retarder in heat, accelerator in cold. Warranty terms: What’s covered; what voids it (e.g., re-introduced water at edges).Owner Checklists
Pre-Decision Checklist
- Photograph cracks with a ruler for width and recheck in 4–8 weeks to detect movement. Dump a hose by edges to see where water goes; plan downspout extensions and grading. Tap-test for hollow spots; mark delaminations to estimate patch or R&R footprint.
Day-of-Work Controls
- Verify mechanical CSP (visual coupons), dust-free surface, and bond coat timing. Confirm saws/blades on site and the joint-cut schedule. Stage curing compound and sprayers; in summer, have shade/windbreaks ready.
Frequently Asked Questions
- Will a bonded overlay hide all cracks? Only if cracks are static and honored in the new joint plan. Moving cracks reflect through. Do fibers replace rebar in overlays? Fibers help with plastic-shrinkage control but do not replace steel for crack-width control or load transfer at thresholds. Is higher PSI the cheap durability fix? Not alone. Low water–cement ratio, air-entrainment, joint timing, and curing/sealing matter more than nominal PSI. Can I just pour over dirt to save money? Pouring on dirt is a false economy. Use compacted DGA base; otherwise you buy cracks, chips, and early replacement.
Authority Reference
For proportioning, exterior durability, overlays, and jointing fundamentals, see the Portland Cement Association. For turnkey help comparing repair vs. replacement, request a consult: contact our KC team.
Bottom Line
Repairs are cheapest when the slab is sound and the damage is small or cosmetic. Replacement is cheaper over the life of the slab when you have base failure, active movement, or pervasive weakness—especially in Kansas City’s demanding climate. Fix water first, stabilize support where needed, then choose a repair, overlay, or replacement with disciplined jointing and immediate curing. That’s how you spend once and stop the cycle of repeat fixes. Explore options for driveways, patios, and foundations in the KC metro.
Kansas City Concrete Contractor Services
6041 Walrond Ave
Kansas City, MO 64130
Phone: (816) 408-3461
https://kcityconcretecontractors.com