Ready-Mix vs Site-Mixed Concrete: What's the Difference?
Ready-mix arrives by truck with precise proportions. Site-mixed is hand-mixed on location. Here's when each makes sense and what it costs.
Quick Answer: Ready-mix concrete is batched at a plant and delivered by truck ($140-$200 per cubic yard + delivery). Site-mixed concrete is mixed on location using bagged cement ($4-$6 per 80lb bag, about $300/yard after labor). Ready-mix wins for jobs over 1 cubic yard; site-mixed works for small repairs and remote locations.
What Is Ready-Mix Concrete?
Ready-mix concrete is manufactured at a batching plant under controlled conditions and delivered to your job site in a rotating drum truck. The plant measures exact proportions of cement, water, aggregates, and admixtures according to the specified mix design.
How Ready-Mix Works
- You order a specific mix: Tell the plant what PSI you need (typically 3000-4000 for residential), plus any admixtures (fiber, air entrainment, accelerators)
- Plant batches the concrete: Computerized systems weigh and combine ingredients precisely
- Truck delivers: The rotating drum keeps concrete mixed during transport
- You have 90 minutes: From water hitting cement, you have about 90 minutes before concrete starts setting
Ready-Mix Advantages
- Consistent quality: Plant-controlled proportions ensure specified strength
- Large volumes fast: A truck delivers 8-10 cubic yards in one load
- Less labor: No mixing by hand—just place and finish
- Verified strength: Plants provide batch tickets documenting the mix
- Admixtures available: Fibers, accelerators, retarders, and color mixed in
Ready-Mix Disadvantages
- Minimum orders: Most plants require 1 cubic yard minimum
- Short load fees: Orders under full truck capacity cost extra ($50-$100+)
- Access required: Truck needs to reach the pour site (or you pay for pumping)
- Time pressure: Once it arrives, you must place it quickly
- Scheduling: Must coordinate delivery with your crew's readiness
What Is Site-Mixed Concrete?
Site-mixed concrete is mixed at the job location using bagged cement (or bulk cement), aggregates, and water. You control the mixing process using a mixer, wheelbarrow, or mixing tub.
How Site-Mixing Works
- Buy materials: Bagged concrete mix (pre-blended) or separate cement, sand, and gravel
- Measure proportions: Follow bag instructions or a standard ratio (1:2:3 cement:sand:gravel)
- Add water: Mix until workable but not soupy
- Place immediately: Small batches mean you can pace yourself
Site-Mixed Advantages
- Small quantities: Perfect for jobs under 0.5 cubic yards
- No scheduling: Mix when you're ready, stop when you want
- Remote locations: Works where trucks can't reach
- Full control: Adjust mix as you work
- No minimums: Buy exactly what you need
Site-Mixed Disadvantages
- Inconsistent quality: Human error in measuring affects strength
- Labor intensive: Mixing by hand is exhausting work
- Slow for large jobs: A cubic yard takes hours to mix by hand
- No verification: You can't prove the mix met specifications
- Limited admixtures: Harder to incorporate fibers or special additives
Cost Comparison
| Factor | Ready-Mix | Site-Mixed (Bags) |
|---|---|---|
| Material cost per yard | $140-$200 | $250-$350 (45+ bags) |
| Delivery | $50-$150 | Your truck/trailer |
| Labor (1 yard) | 30 min place/finish | 4-6 hours mixing |
| Minimum order | 1 yard ($200+) | 1 bag ($5) |
| Short load fee | $50-$100 | None |
| Equipment needed | None (truck pours) | Mixer or wheelbarrow |
Break-Even Point
For most projects, ready-mix becomes cheaper at about 1 cubic yard. Below that, the minimum order fees and short load charges make bagged concrete competitive despite higher per-yard material cost.
The math changes if you value your time. Mixing a cubic yard by hand takes 4-6 hours of hard labor. If your time is worth $50/hour, that's $200-$300 in labor versus 30 minutes with ready-mix delivery.
When to Use Ready-Mix
Best Applications
- Driveways and patios: Any slab over 100 square feet
- Foundations: Footings, stem walls, slabs
- Sidewalks: Long runs where consistency matters
- Pool decks: Large areas requiring uniform finish
- Commercial work: Any job requiring verified strength
Order Guidelines
- Order 10% extra for waste and spillage
- Have your forms, rebar, and crew ready before the truck arrives
- Know your access—can the truck reach the pour site?
- Have a plan for excess concrete (extra forms, wheelbarrow paths)
When to Use Site-Mixed
Best Applications
- Fence posts: Small amounts per hole
- Small repairs: Patching, crack filling
- Setting posts/poles: Mailboxes, signs, deck posts
- Remote locations: Backyard projects with no truck access
- DIY projects: Where you control the pace
Tips for Site-Mixing
- Use a mixer for anything over 2 bags—wheelbarrow mixing is brutal
- Measure water carefully—too much weakens concrete dramatically
- Mix in shade if possible—hot sun accelerates setting
- Work in small batches you can place within 30 minutes
Quality Comparison
| Quality Factor | Ready-Mix | Site-Mixed |
|---|---|---|
| Strength consistency | Excellent (plant-verified) | Variable (depends on mixing) |
| Water-cement ratio control | Precise | Approximate |
| Aggregate gradation | Optimized | Depends on bagged product |
| Air entrainment | Specified exactly | Usually not available |
| Documentation | Batch tickets provided | None |
For structural work or anything requiring verified strength, ready-mix is the only professional choice. Site-mixed works for non-structural applications where exact specifications aren't critical.
Hybrid Option: Volumetric Mixers
Volumetric mixer trucks carry raw materials separately and mix concrete on-site. You get the consistency of ready-mix with the flexibility to pour exact quantities without waste.
Volumetric Advantages
- Pay only for what you use
- Adjust mix on the fly
- No time pressure—concrete is fresh as you need it
- Can pour different mixes from one truck
Volumetric Disadvantages
- Higher per-yard cost than traditional ready-mix
- Not available everywhere
- Still requires truck access
FAQ
How many bags of concrete make a cubic yard?
About 45 bags of 80-lb concrete mix make one cubic yard. At $5-$6 per bag, that's $225-$270 in materials alone—before labor.
Can I add water to ready-mix concrete?
Only if the batch ticket allows it and the driver adds it. Adding water on-site reduces strength—every extra gallon per cubic yard drops strength by 200-300 PSI. Never add water without documentation.
How long can ready-mix sit in the truck?
About 90 minutes from batching, or 300 drum revolutions. After that, concrete begins setting and workability drops. In hot weather, this window shortens significantly.
Is bagged concrete as strong as ready-mix?
Quality bagged concrete (like Quikrete 5000) can match ready-mix strength when mixed properly. The challenge is consistency—plant batching eliminates human error in proportioning.
What's the minimum ready-mix order?
Most plants require 1 cubic yard minimum. Orders under a full truck (8-10 yards) typically incur short load fees of $50-$100+ per yard under minimum.
Key Takeaways
- Ready-mix: Plant-batched, truck-delivered, consistent quality, best for jobs over 1 cubic yard
- Site-mixed: Mixed on location, labor-intensive, best for small repairs and remote sites
- Cost break-even is around 1 cubic yard—but factor in your labor time
- Ready-mix provides documentation; site-mixed doesn't
- For structural work, ready-mix is the professional standard
- Volumetric mixers offer a hybrid option with on-site mixing flexibility
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