A solid sub-base aggregate is essential to the construction process. Any pavement or ground slabs will require support from a solid foundation and will rest on top of the subgrade, often compact or native soil. Choosing the right subbase is critical to the project, and knowing which will work best is difficult with so many options available.

What is a sub-base?

A sub-base is an aggregate or mix of aggregate that creates a load-bearing base layer ready for applications such as pathways, pavements and road construction. It can also support smaller projects such as artificial grass or garden patios. Sub-base material is usually crushed granite or limestone and is designed to balance high-traffic areas. The sub-base is heavily responsible for long-lasting, high-quality roads and pavements.

While the top surface may need replacing in a few years, a sub-base may not require an upgrade so soon. In many circumstances, the top layer gets replaced without a reinstallation of sub-base materials.

Why do I need a sub-base?

It might seem cheaper to skip sub-base for projects, but as time goes by, more money will have to go into repairs or replacements of pavements and roads where there is heavy footfall or traffic. Sub-bases are formed by materials designed for load-spreading and drainage support, making construction last longer and well-protected for years to come.

What sub-base is most suitable?

Unbound materials consist of loose aggregates that do not bond when compacted. Instead, the material naturally interlocks with its particles which can be removed or loosened when and if required.
Another type of sub-base is bound materials – these use cement or bitumen to bind the particles ready for setting, making them difficult to loosen or remove at any point.

Types of sub-base materials

Most sub-base materials consist of:

  • Crushed rock
  • Recycled concrete
  • Granular fill
  • Manufactured aggregate
  • Lean concrete
  • Recycled materials such as brick or crushed concrete

Work with K&B Crushers

Founded in 1993, K&B Crushers have over 25 years of experience in the industry, offering highly reliable and cost-effective recycling, crushing and screening services to the whole of the UK. Get in touch with us today to learn more about how we can help you with your construction projects and sub-base aggregate.