Concrete is the most unforgiving residential material. A mistake in mix ratio, reinforcement placement, sub-base preparation, or curing produces failures that cannot be repaired — only removed and replaced. The visible signs of a bad concrete job emerge within 1-3 years: cracks radiating across the slab, settlement producing tripping hazards, scaling where water has penetrated the surface, and eventually complete failure. And unlike most residential trades where a skilled technician can rework a bad outcome, concrete is essentially one-shot: once the pour is done and set, the options are live with it or demolish and re-pour.
This guide is part of the Know Before You Hire series. At Home Services Co, our concrete services follow the full preparation and pour protocol described below.
Concrete is four things working together. One: the mix itself (cement, aggregate, water, admixtures). Two: the sub-base preparation (compacted gravel, proper drainage, correct depth). Three: the reinforcement (rebar, wire mesh, fiber reinforcement). Four: the finishing and curing (float work, edging, control joints, moisture retention during cure). Skip any of these and the pour fails. Do all four right and the pour lasts generations.
Sub-base. The sub-base is the compacted gravel and prepared ground under the concrete. For driveways, sidewalks, and patios: 4-6 inches of compacted crushed stone or gravel. For slabs supporting significant load: more. Sub-base preparation includes: excavation to proper depth, sub-grade compaction, gravel placement, gravel compaction with proper equipment (a plate compactor, not just 'walk it down'), and final grading to proper elevation. A contractor who pours on uncompacted gravel or bare dirt is setting up failure. This step is invisible after the pour — it's also where many cheap bids save money.
Reinforcement. Rebar (steel reinforcing bar) or wire mesh inside the concrete prevents cracking under tension. Residential slabs typically use #3 or #4 rebar on 12-18 inch centers, or 6x6 wire mesh for lighter applications. Fiber reinforcement can supplement rebar/mesh. Skipping reinforcement produces concrete that cracks randomly and widely. A contractor who pours 'plain concrete' for anything other than a small utility pad is cutting a corner that will show up as cracks.
Mix specifications. Residential concrete is typically specified by PSI (compressive strength) — 3,000 PSI for typical residential, 3,500-4,000 PSI for driveways, 4,000+ PSI for heavy-duty or freeze-thaw exposure. Air entrainment (added air bubbles) is required in freezing climates to resist freeze-thaw damage. Slump (a measure of mix fluidity) affects workability and strength — too wet reduces strength. A contractor who accepts whatever comes off the truck without specifying mix is accepting whatever the concrete supplier delivers. Good contractors spec the mix upfront.
Control joints. Concrete shrinks as it cures. Without control joints (saw cuts or tooled joints placed at specific intervals), it cracks randomly. Proper control joints: at regular intervals (typically 8-12 feet for typical slab work), at depth of 25% of slab thickness, cut within 24 hours of pour. A slab without control joints is a slab that will crack — the only question is where. Control joint placement is a designed element, not an afterthought.
Finishing. Screeding (striking off the concrete to grade), floating (initial smoothing), edging (rounding the perimeter), troweling (final smoothing or broom finish for traction). Each step has timing requirements based on concrete cure. Too early produces weak surface; too late produces a rough finish. Experienced finishers read the concrete — watching water bleed, testing firmness, working with timing. Inexperienced finishers rush steps and produce flawed surfaces.
Curing. After finishing, concrete must retain moisture during cure (typically 7 days minimum, ideally 28 days) to achieve full strength. Methods: spraying with curing compound, covering with plastic sheeting, periodically wetting the surface. Concrete left to dry in sun and wind without curing achieves maybe 50% of its designed strength. Shortcut contractors skip curing.
Red flag #1: no mix specification on the quote. Good contractors write 3,500 PSI or 4,000 PSI on the quote. Contractors who don't specify are accepting anything from the supplier.
Red flag #2: no reinforcement plan. If the quote doesn't mention rebar, mesh, or fiber reinforcement, ask. Unreinforced slabs are failure-prone.
Red flag #3: no sub-base prep mentioned. Legitimate concrete quotes include excavation, gravel, and compaction as line items. A quote that goes straight from 'dig up existing concrete' to 'pour new' is missing the sub-base step.
Red flag #4: pouring in extreme conditions. Concrete pours should not happen in freezing temperatures without specific cold-weather protocols (additives, insulation blankets, heated water). Pours in extreme heat without hot-weather protocols (shade, cooling, timing) are also problematic. A contractor willing to pour regardless of conditions is a contractor willing to produce substandard concrete.
Red flag #5: no control joint plan. Ask about control joints. A contractor who shrugs is a contractor who doesn't plan them — meaning random cracks.
Red flag #6: no curing plan. 'We'll just let it dry' is not a curing method. Ask specifically.
Pricing reality. Concrete driveway (typical 500 sq ft): $3,000-$7,500 depending on thickness, reinforcement, and finish. Concrete patio (300 sq ft): $2,500-$6,000. Sidewalk or walkway: $8-$15 per linear foot. Decorative stamped concrete: 1.5x-3x standard pricing. Foundation pour (significant structural work): scoped separately. Concrete removal and re-pour: add $3-$8 per sq ft for removal. These are market ranges.
Decorative options. Stamped concrete (impressed with patterns resembling stone, brick, tile): moderate upcharge, significant aesthetic improvement. Colored concrete: integral color (mixed in) or surface color (broadcast on wet concrete). Exposed aggregate: final surface treatment that exposes embedded stones. Polished concrete: grinding and sealing for smooth high-end finish (interior applications). Each adds cost and complexity. Decorative work requires more specialized contractors than basic flatwork.
Drainage. Every concrete slab has drainage implications. Driveways should slope away from the house (typically 1-2% minimum). Patios should drain away from structures. Improper slope ponds water, produces freeze-thaw damage in cold climates, and in severe cases causes foundation water issues. Ask about the drainage plan before pouring.
Existing concrete condition. If you're replacing existing concrete, the contractor should assess what's there — not just demo and re-pour without looking. Signs of sub-base issues (settlement, heaving, moisture) should be addressed during the re-pour. 'Just replace the top' without checking sub-base is setting up the new pour to repeat the old pour's problems.
Timing and weather. Pour timing matters. Pours done in the middle of summer heat without proper cooling, or in cold weather without warming, produce substandard concrete. A good contractor schedules around weather. A rush-to-pour contractor pours regardless of conditions.
Warranty. Concrete work warranties typically run 1-2 years on workmanship, and concrete manufacturers don't warranty concrete after installation (the product is the installation). Workmanship warranty should cover specific defects (cracking beyond normal control joint activity, scaling, surface issues). Get it in writing. See warranty vs guarantee.
Permits. Most jurisdictions require permits for significant concrete work — driveways, large patios, retaining walls. Permit requirements vary significantly by municipality. See does this job need a permit.
The summary. Spec the mix PSI. Demand sub-base preparation as a line item. Require reinforcement. Plan control joints. Require curing. Check drainage slope. Pick a contractor with experience in your climate's specific challenges. Don't pour in extreme weather.
At Home Services Co, our concrete services specify mix PSI, proper sub-base, reinforcement, control joints, and curing protocols. Related: deck builder, fence installer, landscaper, general contractor, pricing, book, or the full series.