Concrete Selection

Types of Concrete

General Mixes (GEN) General mixes (GEN) are produced to British and European standards to guarantee high quality. Each has a designed strength and minimum cement content. They are most commonly used in foundations or domestic flooring.
Reinforced Mixes (RC) Most commonly used where steel reinforcement is present. The characteristics of each mix is specified by British and European standards to produce strength and durability qualities. These help to reduce the risks of the steel being attacked by aggressive chemicals.
Standard Mixes (ST) These have a broad range of uses, and while there is no guaranteed designed strength, a minimum cement content is specified in British and European standards. The mixes range from ST1 to ST5 and their uses range from kerb backing to concrete slabs.
Designed Mixes (C) Usually specified by the engineer, architect or designer, they are manufactured to achieve a particular strength. Other properties may also be specified. These details would usually be found on the construction drawings, specification or bill of quantities.


Ready-Mixed Concrete Consistence Classes

Slump Class Range of Slump
S1 10 - 40mm
S2 50 - 90mm
S3 100 - 150mm
S4 160 - 210mm


Guidance on the selection of designated concrete in housing and other applications BS EN 8500-1

Application Designated Concrete Recommended Consistence Class
Unreinforced foundations and associated works
Blinding and mass concrete fill GEN1 S3
Strip footings GEN1 S3
Mass concrete foundations GEN1 S3
Trench fill foundations GEN1 S4
Drainage works to give immediate support GEN1 S1
Other drainage works GEN1 S3
Oversite below suspended slab GEN1 S3
Unreinforced foundations requiring DC-2 to DC-4 concrete
DC-2 FND2 S3
DC-2z FND2Z S3
DC-3 FND3 S3
DC-3z FND3Z S3
DC-4 FND4 S3
DC-4z FND4Z S3
DC-4m FND4M S3
General applications
Kerb bedding & backing GEN0 S1
House floors with no embedded metal    
- Permanent finish added
e.g a screed or floating floor
- No permanent finish to be added
e.g carpeted
Garage floors with no embedded metal GEN3 S2
Wearing surface: Light foot and trolley traffic RC25/30 S2
Wearing surface: general industrial RC32/40 S2

Selection of Consistence

The selection of fresh concrete should be suitable for the conditions of handling and placing so that after compaction, concrete surrounds all reinforcement, tendons and ducts and completely fills the formwork. The table below gives guidance on the consistence expressed as slump [S (number)] classes appropriate to different uses. Where a concrete is to be laid on a slope, a lower slump class than that given in table below might be necessary.

Use of Concrete Form of Compaction Consistence Class
Consistence suitable for different uses of in-situ concrete
Kerb bedding and backing Tamping S1
Floors and hand placed pavements Poker or beam vibration S2
Strip footings Poker or beam vibration S3
Mass concrete Poker or beam vibration S3
Foundations Poker or beam vibration S3
Blinding Poker or beam vibration S3
Normal reinforced concrete in slabs, Poker or beam vibration S3
beams, walls and columns and/or tamping  

How Much Concrete do you Need?

You can calculate your concrete requirements by multiplying the length x breadth x depth of the area or areas which the concrete is needed to fill.

Be sure to make allowances for areas which may be slightly wider or deeper. We can supply and deliver concrete with a minimum quantity of 0.5 cubic metres up to 7 metres in one truck load.

As an estimate, one cubic metre is approximately 20 to 25 wheelbarrow loads.