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For projects larger than about 1 cubic yard (roughly a 10×10 ft slab at 4 inches thick), ready-mix delivered by truck is almost always more economical than bagged concrete. Ready-mix is sold by the cubic yard and typically costs $120–$200 per yard depending on your region, mix design, and delivery distance. The truck arrives with the concrete already mixed to your specified strength (typically 3,000–4,000 PSI for residential slabs), so you simply pour, screed, and finish.

Bagged concrete — products like Quikrete or Sakrete — is best for small jobs like fence post footings, repair work, or projects under half a cubic yard. An 80-lb bag yields approximately 0.60 cubic feet of concrete. A 10-bag purchase of 80-lb bags gives 6 cubic feet, which is just over 0.22 cubic yards — enough for a small patio section or several footings. The material cost per cubic yard is significantly higher with bagged concrete, but the flexibility and zero minimum order make it worthwhile for small tasks.

Mix strength matters for durability. Standard residential slabs use a 3,000 PSI mix. Driveways and structural elements typically specify 4,000 PSI. High-traffic areas or freeze-thaw climates may require 5,000 PSI with air entrainment (small air bubbles that relieve freeze-expansion pressure). When ordering ready-mix, specify the PSI, slump (how workable the concrete is — typically 4–5 inches for residential pours), and whether you need fiber reinforcement or air entrainment. These specifications affect the price but dramatically affect performance.

Thickness is one of the most important variables in concrete design. Too thin and the slab cracks under load; too thick and you waste material and money. For standard applications: sidewalks and pathways use 3.5 to 4 inches; residential driveways use 4 inches (some codes require 5 inches where heavy trucks will park); patios use 4 inches; garage floors use 4 to 6 inches depending on whether heavy vehicles will use them; structural footings are sized by engineering calculation but commonly 6 to 12 inches thick.

Reinforcement complements thickness. Residential slabs typically use either welded wire mesh (6×6 W1.4×W1.4) or #3 or #4 rebar on 18-inch centers to control cracking. Mesh and rebar must be elevated to sit in the middle third of the slab's depth — use chairs or dobies to keep reinforcement at the correct depth. Fiber reinforcement (polypropylene or steel fibers mixed into the concrete) reduces plastic shrinkage cracking but is not a substitute for structural rebar in load-bearing applications. Always check local building codes for reinforcement requirements before pouring.

Control joints — intentional weakened lines cut or formed into the slab — direct where the slab cracks as it cures and shrinks. A general rule is to place control joints no farther apart than 2–3 times the slab thickness in feet. For a 4-inch slab, joints every 8–10 feet in both directions. Joints should be cut to one-quarter of the slab depth — 1 inch deep for a 4-inch slab. Cutting joints too late (after the concrete has hardened) or skipping them altogether is the most common reason residential slabs develop visible surface cracks.

Round column footings use a different formula: Volume = π × r² × height, where r is the radius in feet. A 12-inch diameter (6-inch radius = 0.5 ft) footing poured 12 inches deep contains π × 0.5² × 1 = 0.785 cubic feet. A typical deck with 6 footings of this size needs 4.71 cubic feet — about 0.17 cubic yards, or 8 bags of 80-lb concrete. For tall piers, the same formula applies. Use 0.5 ft (6 in), 0.667 ft (8 in), or 1 ft (12 in) as your radius depending on the post or column diameter specified by your plan.

Continuous footings (strip footings for foundations or retaining walls) are rectangular: Volume = Length × Width × Depth. A 40-foot continuous footing 16 inches wide and 10 inches deep contains 40 × (16/12) × (10/12) = 44.4 cubic feet = 1.65 cubic yards. Always verify footing dimensions against your engineer's drawings or local prescriptive requirements — footing width must be at least twice the wall thickness it supports, and minimum depth varies by frost depth in your climate. In cold climates, footings must extend below the frost line, which ranges from 12 inches in mild areas to 48 inches or more in northern regions.

Steps and irregular shapes can be broken into rectangular or cylindrical sections, calculated separately, then added together. Curved features are approximated as a series of short straight segments. For complex projects, a professional estimator or ready-mix supplier can review your plans and provide a material takeoff. Always order 8–10% more than your calculated volume — it's far better to have a partial leftover drum than to run short and create a cold joint (a weak plane where new concrete meets partially-cured existing concrete).

Curing is the process of keeping freshly-poured concrete moist during the first 7–28 days as it gains strength through hydration. Concrete achieves roughly 70% of its design strength in 7 days and 95% in 28 days, but only if it stays moist throughout. Premature drying — from sun, wind, or low humidity — dramatically reduces final strength and causes surface cracking. Standard curing methods include covering with plastic sheeting or wet burlap, applying a liquid curing compound immediately after finishing, or fogging the surface with water multiple times per day for the first week.

Finishing sequence matters. After screeding (striking off excess concrete flush with the form tops), use a bull float to smooth the surface and push down aggregate. Wait for bleed water to evaporate before troweling — troweling over bleed water weakens the surface layer. For outdoor slabs, a broom finish (dragging a stiff bristle broom across the surface) creates a non-slip texture. For interior floors requiring a smooth, hard surface, use a power trowel for final finishing. Adding color (integral pigment or surface-applied stain) must be planned before the pour.

Temperature affects concrete performance significantly. Do not pour concrete when air temperatures are below 40°F without cold-weather precautions — concrete can freeze before it gains strength, permanently weakening the structure. In hot weather above 90°F, use chilled water, shaded aggregate, and ice in the mix to lower the concrete temperature, and plan your pour for early morning when temperatures are lower. The ideal pouring temperature is 50–75°F with mild sun and low wind. In extreme conditions, consult your ready-mix supplier for admixture recommendations and adjusted water-cement ratios.

Concrete is sold in cubic yards for ready-mix and in bags by weight for bagged product. The standard conversion is 27 cubic feet per cubic yard. Ready-mix trucks typically have a minimum order of 1 cubic yard and charge a short-load fee for orders under their minimum — often 4–5 yards — so plan neighboring projects together to meet minimums.

The weight of concrete is approximately 150 pounds per cubic foot, or about 4,050 pounds per cubic yard. A fully loaded ready-mix truck carrying 10 cubic yards weighs roughly 20 tons. Ensure your driveway and access route can support this weight before scheduling delivery. For sites with restricted access, pump trucks can deliver concrete over fences, walls, and other obstacles at additional cost.

Common concrete project mistakes include: not accounting for the subgrade (concrete poured over soft soil or poorly compacted fill will crack), skipping rebar or mesh reinforcement, placing control joints too far apart, not curing properly, and ordering exactly the calculated volume without a waste buffer. Planning for these factors before the truck arrives is far easier than dealing with structural failures or visible cracking after the concrete has hardened.