Complete Comparison Guide for UK Construction Projects
Choose the Right Concrete Delivery Method for Your Build
Choosing between ready-mix concrete and site-mixed concrete is a critical decision that impacts project cost, quality, timeline, and efficiency. Ready-mix concrete is manufactured at a centralized batching plant and delivered to site in mixer trucks, offering consistent quality and minimal waste. Site-mixed concrete is produced on-site using portable mixers, providing flexibility for smaller projects or remote locations where ready-mix delivery is impractical.
In 2026, ready-mix concrete dominates UK commercial and residential construction due to its reliability, time-efficiency, and compliance with BS EN 206 and BS 8500 standards. However, site-mixed concrete remains viable for small DIY projects, repairs, remote sites, and situations requiring frequent small batches. This comprehensive guide examines both methods to help you make informed decisions for your construction project.
Ready-mix concrete (RMC) is manufactured in controlled conditions at specialized batching plants using automated weighing, mixing, and quality control systems. Concrete is mixed in transit mixers and delivered to construction sites within 90 minutes of batching. The Concrete Society provides extensive guidance on ready-mix concrete specifications, delivery, and placement procedures.
Location: Centralized batching plant
Equipment: Computer-controlled batching systems
Mixing: Transit mixer during transport (6-9 m³ capacity)
Quality Control: Automated weighing, continuous monitoring
Delivery Radius: Typically 20-30 miles from plant
Delivery Time: Within 90 minutes of batching
Minimum Order: Usually 1-2 m³ (small load surcharge applies)
Access Required: 3-4m width for mixer truck
Mix Accuracy: ±2% tolerance on all constituents
Batch Consistency: Uniform quality across entire project
Testing: Regular cube testing, slump checks on delivery
Certification: BS EN 206 compliant with delivery tickets
Commercial: Multi-storey buildings, offices, warehouses
Residential: Foundations, floors, driveways (2m³+)
Infrastructure: Roads, bridges, car parks
Volume: Any project requiring 2m³+ in single pour
Site-mixed concrete involves mixing cement, aggregates, sand, and water at the construction site using portable mixers (typically 100-350 litre capacity). This traditional method requires manual batching of materials, consistent mixing procedures, and careful quality control to achieve specified strength and workability. Site mixing is common for small-scale projects, repairs, and locations where ready-mix delivery is not feasible.
Mixer Size: 100-350 litre portable mixer typical
Batching: Manual measurement using buckets/shovels
Power: Electric (240V) or petrol engine
Hire Cost: £30-£60 per day for mixer rental
Cement: Waterproof storage, raised off ground
Aggregates: Clean, segregated storage for sand/gravel
Space Required: 10-15m² minimum for materials
Protection: Cover sheets to prevent contamination
Mixing Crew: 2-3 laborers for continuous production
Output Rate: 1-2 m³ per hour typical
Skill Level: Moderate - requires mixing experience
Labor Cost: £35-£50 per hour for crew
Small Projects: Under 2m³ total requirement
DIY Work: Garden walls, small pads, repairs
Remote Sites: Beyond ready-mix delivery radius
Phased Work: Multiple small pours over extended period
Understanding key differences between ready-mix and site-mixed concrete helps determine the most appropriate method for your project. Factors including volume, timeline, quality requirements, site constraints, and budget all influence this decision.
| Factor | Ready-Mix Concrete | Site-Mixed Concrete |
|---|---|---|
| Quality Control | Excellent - automated batching, strict controls | Variable - depends on operator skill |
| Consistency | High - uniform mix throughout project | Moderate - can vary between batches |
| Time Efficiency | Fast - ready to use immediately on arrival | Slow - 1-2 m³/hour mixing rate |
| Labour Requirements | Low - only placement crew needed | High - mixing + placement crews |
| Material Waste | Minimal - precise batching | Moderate - spillage during handling |
| Cost per m³ | £100-£130 delivered (C20/25 to C28/35) | £60-£90 materials only + labour + equipment |
| Minimum Quantity | 1-2 m³ (small load surcharge applies) | No minimum - mix as needed |
| Ideal Volume Range | 2 m³ and above | Under 2 m³ |
| Site Access | Requires 3-4m width for mixer truck | Minimal - wheelbarrow access sufficient |
| Storage Space | None - delivered ready to use | 10-15 m² for materials |
| Weather Sensitivity | Low - rapid placement possible | High - extended exposure during mixing |
| Strength Certification | Yes - delivery tickets with full specification | No - estimated strength only |
| BS EN 206 Compliance | Full compliance guaranteed | Difficult to demonstrate compliance |
| Building Control | Easily accepted with delivery documentation | May require cube testing for approval |
| Mix Flexibility | Limited - order specific grade | High - adjust proportions on-site |
| Environmental Impact | Lower CO₂ per m³ (efficient batching) | Higher waste, less efficient processes |
Total project costs extend beyond concrete material prices to include labor, equipment, delivery, and time factors. For volumes above 2m³, ready-mix typically offers better value despite higher per-m³ costs, while site-mixing can be economical for very small quantities or remote locations.
| Item | Cost 2026 | Notes |
|---|---|---|
| C20/25 Ready-Mix Delivered | £100-£115/m³ | Standard domestic grade, within 20 miles |
| C25/30 Ready-Mix Delivered | £105-£120/m³ | Light structural applications |
| C28/35 Ready-Mix Delivered | £110-£130/m³ | Structural beams, columns, slabs |
| Small Load Surcharge | £60-£100 | For loads under 4m³ |
| Extra Delivery Distance | £3-£5 per mile | Beyond standard 20-mile radius |
| Waiting Time (if site not ready) | £100-£150/hour | After free waiting period (15-30 mins) |
| Concrete Pump Hire | £250-£400/day | Line pump for access issues |
| Labour (Placement & Finishing) | £30-£50/m³ | 2-3 person crew |
| Item | Cost 2026 | Notes |
|---|---|---|
| Cement (CEM I 42.5N) | £6-£9 per 25kg bag | Approximately 7-8 bags per m³ |
| Sharp Sand | £40-£60 per tonne | ~0.7 tonnes per m³ |
| Gravel/Aggregate (10-20mm) | £35-£55 per tonne | ~1.2 tonnes per m³ |
| Ballast (All-in aggregate) | £40-£65 per tonne | Alternative to separate sand/gravel |
| Mixer Hire (Electric 250L) | £30-£50/day | Weekly hire £100-£150 |
| Mixer Hire (Petrol 350L) | £50-£75/day | For larger batches or no power |
| Labour (Mixing + Placement) | £35-£50/hour | 2-3 person crew required |
| Total Material Cost per m³ | £60-£90 | Plus labour + equipment hire |
💰 Cost Breakeven Analysis:
Ready-mix concrete is the preferred choice for most UK construction projects due to quality assurance, time efficiency, and regulatory compliance. Quarry Products Association members produce 95% of UK concrete using ready-mix methods, reflecting industry confidence in this delivery system.
✓ Choose Ready-Mix Concrete When:
Typical Volume: 4-8 m³ for standard 3-bed house
Recommendation: Ready-mix strongly advised
Reason: Requires continuous pour, structural quality, Building Control compliance
Grade: C20/25 (GEN3) minimum for strip foundations
Typical Volume: 2-4 m³ for single garage
Recommendation: Ready-mix preferred
Reason: Better finish, faster completion, consistent strength
Grade: C20/25 with 100mm thickness typical
Typical Volume: 3-6 m³ for standard car driveway
Recommendation: Ready-mix essential
Reason: Large area requires consistent mix and rapid placement
Grade: C25/30 for durability under vehicle loads
Typical Volume: 10-100+ m³
Recommendation: Ready-mix only realistic option
Reason: Volume impossible to site-mix economically
Grade: C28/35 to C32/40 depending on loading
Site-mixed concrete remains viable for specific scenarios where ready-mix delivery is impractical, uneconomical, or unnecessary. DIY projects, small repairs, and remote locations often benefit from on-site mixing flexibility despite the quality and efficiency trade-offs.
⚠️ Choose Site-Mixed Concrete When:
Typical Volume: 0.3-0.8 m³ for 5-10m wall
Recommendation: Site-mixing suitable
Reason: Small volume, non-structural, phased construction possible
Mix: 1:6 cement:ballast for foundations
Typical Volume: 0.05-0.2 m³ total
Recommendation: Site-mixing or pre-mixed bags
Reason: Tiny quantities, spread over time
Mix: 1:5 cement:ballast or use postcrete
Typical Volume: 0.5-1.5 m³
Recommendation: Site-mixing economical for DIY
Reason: Below ready-mix minimum, DIY-friendly project
Mix: 1:5 cement:ballast, 75-100mm thick
Typical Volume: 0.1-0.5 m³
Recommendation: Site-mixing or bagged concrete
Reason: Small patches, intermittent work
Mix: Match existing concrete strength
Concrete quality directly impacts structural safety and durability. Ready-mix concrete manufactured to BS EN 206 provides documented compliance with Building Regulations, while site-mixed concrete requires careful management to achieve comparable standards. Building Regulations Approved Document A specifies minimum concrete standards for structural elements.
| Quality Aspect | Ready-Mix Concrete | Site-Mixed Concrete |
|---|---|---|
| Material Batching | Computer-controlled to ±2% accuracy | Manual measurement, ±5-10% typical |
| Mix Consistency | Identical across all batches | Varies between batches |
| Strength Certification | Delivery ticket with full specification | None unless tested independently |
| Cube Testing | Regular plant testing, on-site sampling available | Requires separate arrangement with lab |
| BS EN 206 Compliance | Guaranteed by certified batching plant | Difficult to demonstrate compliance |
| Traceability | Full documentation from plant to pour | Limited records of material sources |
| Aggregate Quality | Pre-tested, certified aggregates | Depends on supplier, often uncertified |
| Water Control | Precise metering, consistent W/C ratio | Estimated by eye, variable W/C ratio |
| Admixtures | Computer-dosed plasticizers, retarders | Rarely used (manual dosing unreliable) |
| Strength Variation | Low - typically ±3 N/mm² across project | High - can be ±8-12 N/mm² between batches |
If site-mixing is necessary, following proper procedures improves quality and consistency. Accurate batching by volume (using consistent containers), thorough mixing (2-3 minutes), and controlled water addition are critical for achieving specified strength and durability.
✓ Site-Mixing Guidelines for Best Results:
Ready-mix concrete production offers environmental advantages through efficient batching, reduced waste, and optimized logistics. However, transportation emissions increase with delivery distance. Site-mixing reduces transport but increases material waste and energy consumption per m³ produced.
CO₂ per m³: 120-150 kg (average C25/30 mix)
Material waste: <2% due to precise batching
Transport emissions: 15-30 kg CO₂ depending on distance
Efficiency: Centralized production reduces overall energy
CO₂ per m³: 130-170 kg (less efficient mixing)
Material waste: 5-10% spillage and over-ordering
Transport emissions: Lower (bulk material delivery)
Efficiency: Small-scale mixing less energy efficient
Ready-mix: Order exact quantities, return unused concrete to plant for recycling
Site-mix: Calculate accurately, buy materials in appropriate quantities
Both: Plan concrete placement carefully to minimize leftover material
Recycled aggregates: Available in ready-mix, reduces virgin material extraction
Low-carbon cements: CEM II/III options reduce embodied carbon 15-30%
Optimized mixes: Ready-mix plants design mixes for minimum cement content