How much Sub-base do I need | Avon Material Supplies

How much sub-base do I need for my project?

Construction projects often require sub-bases. However, it’s sometimes unclear how much you need, which type you should get, or where you should get it from.

Fortunately, this article can help, read on to learn:

Alternatively, just call our friendly team on 01202 579579.

Sub base material

What is a sub base, and what aggregates can be used to form a sub base?

A sub-base is an aggregate or aggregate mix that forms a sound, load-bearing base layer. In some applications, it provides drainage with the right choice of material, such as limestone chippings.

Sub-bases work by distributing loads over a large area. When laid in a thin layer using the right combination of crushed materials, they can improve the ground’s ability to handle heavy loads, enhancing the longevity of structures built on top.

Several sub-base aggregates are widely available in the UK, each for different applications and specifications.

  • Type 1(sometimes called DTp1 or 804)is the most common aggregate used for sub-bases. AMS provides Type 1 Limestone, which is a primary aggregate and the much requested recycled alternative, Type 1 Recycled. Engineers and construction firms frequently use these materials because they minimise the voids and hollow spaces that can compromise structural integrity.
  • 6F5 Concrete is a recycled aggregate suitable for use as either a capping layer for larger roads or as a sub-base on construction projects. The material is made up of crushed concrete from 75mm down to dust.
  • Type 3 limestone is open graded with reduced fines (not zero) which makes it ideal when a permeable sub-base is required where drainage is an issue, also suitable for sub-bases as it comprises of the same material uses in type 1 limestone with the only difference being the size of the stones, which vary from 40mm to dust in our Type 3 Limestone.
  • Type 2, Type 3, and Type 4. Types 2,3, and 4 have different grading profiles, depending on their use. Type 1 has a smaller particle size than Type 3. Type 4 is made of asphalt arisings and can function as an alternative to Type 1.

What projects need a sub-base?

Various projects require sub-bases. They are essential for any work that involves laying a surface on top of the ground. Without a proper sub-base, overlaying constructions may crack, sink or become uneven over time due to settlement or erosion.

AMS commonly supply sub-base materials for projects such as:

Artificial Grass

Sub-bases are suitable for artificial grass installations. They create a smooth surface for installers to lay the synthetic turf on top. Some sub-base aggregates aid the drainage of artificial lawns which is essential for preserving them and preventing the pooling of rainwater.


Construction firms, landscapers and farmers often use sub-bases for paths made of loose material, such as shingle or gravel. The sub-base ensures they are level and durable against traffic and weather conditions.


Civil engineers and contractors use sub-bases for pavements made of bricks, slabs, and blocks to ensure they are level and can withstand heavy loads from the traffic above.


Like paths, roads also require a sub-base. Aggregate provides strength and stability for road surfaces such as asphalt, concrete or block paving. As with artificial grass, it also supports drainage, keeping highways puddle-free during heavy rain storms.


Lastly, sub-bases are a common material for patios. Small granules create a level surface for workers to lay flagstones, bricks or slabs on top. Sub-bases make patios stronger and longer-lasting.

How to work out how much sub base you need?

To figure out how much sub-base you require, you need to know:

  • The depth of the sub-base that your project requires
  • The area of your project
  • The density of your chosen sub-based in tonnes per cubic metre

You can calculate the sub-base volume (if that’s how you’re ordering) by multiplying the area by the depth. To figure out the weight, multiply the volume by the density.

If you are struggling with this, don’t worry we can help you. Give us a call on 01202 579579 and our team of experts can work it out for you.

sub base material being tipped onsite

Get your sub-base from AMS

If you’re looking for sub-base aggregates delivered to your site, business or home on time at competitive prices, then Avon Material Supplies (AMS) can help. We’re a leading supplier in the Dorset and Hampshire area with three decades of experience.

All of the sub-base aggregates AMS supplies are delivered using a tipper or grab truck in either loose or bagged loads.

If you are short of space or only require a small amount of aggregate a bulk bag might be the best choice. The bulk bags AMS use are able to hold up to a tonne of aggregate and are delivered using a grab lorry. If you need a lot of material and have space, a loose load delivery using a tipper truck is a more cost-effective choice.

Pros of using AMS and our Aggregates

AMS are the clear choice for aggregates. Here’s why DIY enthusiasts, tradespeople, construction companies, and landscape gardeners use us:

  • Order online or over the phone – it’s easy to get what you need. Just order via our website or call one of our experts on 01202 579579.
  • Recycled products – access sub-bases that reduce your environmental impact and cut your carbon footprint.
  • Delivered at a time that suits you – AMS delivers to businesses, sites and homes across Dorset, Hampshire and Somerset. Tell us when you’d like your aggregate to arrive, and get the job done.

Interesting? For advice or to place an order, please call our friendly team on 01202 579579.

Or enquire about setting up a trade account by emailing

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