Ballast – What Is It?
Pre-mixed aggregate combining gravel and sharp sand for concrete
Ballast / All-in Aggregate
What It's Used For
Ballast is the convenient all-in-one aggregate for general concrete work where exact specifications aren't critical.
- Concrete foundations
- Footings and ground beams
- Shed and garage bases
- Fence post concrete
- General concreting
- Oversites and blinding
- Non-structural concrete
Material Composition
Pre-blended mix of coarse aggregate and sand in the correct proportions for concrete.
- 60% coarse aggregate (4-20mm)
- 40% sharp sand (0-4mm)
- Natural river gravel or crushed rock
- Pre-washed to remove fines
- Consistent grading throughout
- Ready to mix with cement
Ballast vs Separate Aggregates
Understanding when to use ballast versus buying sand and gravel separately.
- Ballast: Convenient for standard mixes
- Separate: Better for specific ratios
- Ballast: One product to order
- Separate: Can adjust strength
- Ballast: Good for DIY projects
- Separate: Preferred for structural work
Delivery Options
Multiple delivery formats to suit your project size and access.
- 20-tonne tipper loads
- 10-tonne for smaller sites
- Grab lorry delivery
- 1-tonne bulk bags
- Mixed loads with cement available
Technical Specifications
| Property | Specification |
|---|---|
| British Standard | BS 8500-2 (Concrete Aggregate) |
| Maximum Size | 20mm nominal |
| Grading | 4/20mm coarse with 0/4mm sand |
| Ratio | Typically 60:40 (gravel:sand) |
| Material Type | Thames Valley gravel or crushed limestone |
| Chloride Content | Class CL 0,40 (suitable for reinforced concrete) |
| Documentation | CE marking and aggregate test certificates |
Frequently Asked Questions
What mix ratio for concrete using ballast?
Standard mix is 1:6 (1 part cement to 6 parts ballast) for general purpose concrete. For higher strength, use 1:5. For foundations, 1:6 is adequate. Add water gradually - aim for thick porridge consistency. One 25kg bag of cement to 150kg of ballast gives you approximately 0.11m³ of concrete.
How much ballast do I need?
For 1 cubic metre of concrete using 1:6 mix, you need approximately 1,800kg of ballast and 300kg of cement (12 bags). Coverage: 1 tonne of ballast makes approximately 0.5m³ of concrete when mixed. Always order 10% extra for wastage.
What's the difference between ballast and gravel?
Ballast is pre-mixed gravel AND sharp sand in the correct proportions for concrete. Gravel is just the coarse aggregate (stones) without sand. Using gravel alone requires adding sharp sand separately. Ballast saves time but gives less control over the mix design.
Can I use ballast for drainage?
No - ballast contains sand which reduces drainage capacity. The sand fills the voids between stones, preventing water flow. For drainage, use clean stone like 20mm gravel or MOT Type 2. Ballast is only for concrete production.
Is ballast suitable for structural concrete?
Ballast is fine for most domestic structural work like house foundations when mixed correctly (C20/25 strength). For critical structural work requiring specific strengths, it's better to batch materials separately for precise control. Always follow structural engineer specifications.
Why is my concrete weak when using ballast?
Usually too much ballast in the mix (weaker than 1:6), too much water (over 0.6 water/cement ratio), or poor mixing. Ensure thorough mixing - minimum 3 minutes in mixer, 5-10 minutes by hand. Also check cement date - cement older than 3 months loses significant strength.
Need Ballast Delivered?
All-in aggregate for concrete. Just add cement and water.
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