How Much Ballast and Cement Do I Need, Mix Ratios Explained

Q: How much ballast for 1m3 of concrete?

Around 1.7 tonnes, according to Skip East. TJC's 20 MPa mix uses 1,800 kg of sand and aggregate combined per cubic metre.

Key points

The graphic gives three cement : sand : aggregate ratios by strength: 1:2:4 for 20 MPa, 1:3:6 for 10 MPa and 1:0.75:1.5 for 30 MPa.
All-in ballast is sand and gravel already mixed, so with ballast you only measure cement and ballast. B&Q gives 1 part cement to 5, 4 or 3.5 parts ballast depending on the strength needed [2].
For quantity, TJC Transport’s own article gives 320 kg of cement, 600 kg of sand and 1,200 kg of aggregate for a cubic metre of 20 MPa concrete [1].
Skip East puts the ballast needed at around 1.7 tonnes per cubic metre of concrete [3].
Ratios are by volume, and too much water weakens the mix [2].

The infographic in text

The graphic is titled “How Much Ballast Do I Need?” and is made by TJC Transport, an aggregates, haulage and skip hire firm based in Rayleigh. It has three sections.

What Is Concrete Made Of? “Mixed concrete is made up of basically two materials: Cement (the binder which holds other materials) and Concrete ballast (increases the strength of the concrete).”

More Ado About Concrete. High strength concrete: “This high strength concrete makes it suitable for roads, patio, bridges and other structural uses.” Low strength concrete: “It has a strength of about 14MPa. It is often made by adding foam or using lightweight ballast mix.”

Mixing The Right Amount of Ballast. The section shows a cement mixer icon and three ratio tables:

Strength on the graphic	Cement	Sand	Aggregate
20 MPa	1	2	4
10 MPa	1	3	6
30 MPa	1	0.75	1.5

The footer carries the T.J.C Transport logo, the phone number 01268 780 700, [email protected] and www.tjctransport.co.uk.

How much ballast and cement for a cubic metre

TJC’s article that accompanied the graphic gives the weights behind its 20 MPa mix: 320 kg of cement, 600 kg of sand and 1,200 kg of aggregate for one cubic metre, which it describes as a mix for driveways, paths and other domestic use and as a ballast to cement ratio of 6 to 1 [1]. In 25 kg bags, 320 kg of cement is 12.8 bags (our arithmetic). The same article advises a water to cement ratio between 0.35 and 0.6 [1].

Skip East, an aggregates supplier, uses a 1:5 cement to ballast mix as standard and says you will typically need around 1.7 tonnes of ballast for every cubic metre of concrete, so 2.5 cubic metres needs at least 4.3 tonnes [3]. Measure the volume first (length by width by depth in metres), then scale these figures.

Mixing with all-in ballast

B&Q describes concrete as cement, water, sand and aggregates, and ballast as a ready mix of sand and gravel that saves measuring the two separately [2]. Its three mixes are:

B&Q mix	Cement : sand : aggregate	Cement : ballast	Suggested uses
Standard strength	1 : 2.5 : 3.5	1 : 5	Light wall foundations, concreting in fence posts
Medium strength	1 : 2 : 3	1 : 4	Shed and garage bases
Strong	1 : 1.5 : 2.5	1 : 3.5	Steps, paving and driveways exposed to the weather

B&Q recommends measuring by volume with a separate bucket of the same size for each material, as shovelfuls are hard to keep consistent, and warns that adding too much water reduces strength and can cause cracking [2].

Notes on this infographic

“Two materials”. The graphic says concrete is basically cement and ballast, but its own tables list three dry materials, and water is also needed. B&Q lists cement, water, sand and aggregates [2].
High strength is not defined. The graphic gives no figure for high strength concrete. Wikipedia describes high-strength concrete as having a compressive strength above 40 MPa, and regular concrete as roughly 10 to 40 MPa [4].
The 30 MPa ratio. 1:0.75:1.5 is much richer in cement than B&Q’s strongest mix (1:1.5:2.5) [2]. We could not find a standard that gives this ratio, so treat it with caution and ask a supplier for structural work.
Contact details. The footer email uses a different domain (tjcottis.co.uk) from the website, and tjctransport.co.uk did not respond when we checked, so the original article is linked through an archived copy.

Questions about ballast and cement

How much ballast and cement do I need?

Work out the volume of concrete, then use a ratio. For one cubic metre, TJC gives 320 kg of cement with 1,800 kg of sand and aggregate for a 20 MPa mix [1], and Skip East gives around 1.7 tonnes of ballast at 1:5 [3].

How much cement to ballast?

B&Q gives 1 part cement to 5 parts ballast for standard strength, 1 to 4 for medium and 1 to 3.5 for a strong mix [2]. The graphic’s 20 MPa mix works out at 1 to 6 [1].