Last Modified: February 21, 2024

MOT Type 3 Sub-Base

Less Fines Content for Greater Drainage

Close up of mot type 3 sub-base

By Ben Parrot - Landscape Gardener & Amateur Geologist


Stone landscaping material and construction aggregate

Geological name(s):


Other Name(s):

MOT type 3, type 3 MOT, MOT type 3 aggregate, type 3 sub-base, type 3 hardcore


Welcome to the only encyclopaedia for decorative aggregates and landscaping materials. MOT type 3 is an economical crushed aggregate known for its load-bearing properties and greater drainage properties than other sub-bases. Type 3 sub-base is a commonly used material as a sub-base for construction projects that require a higher percentage of larger-sized aggregate and a lower fines content. It is similar to MOT Type 1, but with less fines - up to 25% of Type 3 aggregate is allowed to be 1mm or smaller. This allows water to drain more freely, making it the most permeable sub-base able to withstand frost when placed at a depth of 450mm thickness from the surface.

To be considered Type 3, the material must meet the Ministry of Transport Specification Clause SHW 805. It was previously known as DOT Type 3 (Department of Transport Type 3).

This is a comprehensive encyclopaedia listing about MOT type 3, a hardscape and construction aggregate. It details the product's specifications, accompanied by photographs, and outlines its benefits, applications, and incompatibilities as a landscaping material. Additionally, this entry serves as a gateway to a wealth of DIY resources, with a list of comparable alternatives, articles offering design inspiration and fundamental principles, and a collection of straightforward, step-by-step instructions for constructing your own hardscaping features.

MOT Type 3 Specifications





fall safety





fish friendly

eco friendly



diy friendly




Generally limestone, granite, basalt or concrete


Generally grey to brown



Crushed aggregate close up

Size Range



Fall Safety

Unsuitable for play surfaces





Fish Friendly


Type 3 sub base close up






Neutral or alkaline



Close up of mot 3


MOT type 3 aggregate is used for its exceptional load-bearing, compaction and superior drainage capacity, making it ideal for use in construction and roadworks as a sub-base layer. Its composition of crushed stone or concrete provides a stable and durable foundation, ensuring long-term structural integrity. Its permeability also makes it an excellent choice for projects requiring higher water drainage than other sub-base materials.

  • Best drainage
  • Hard-wearing
  • Eco-friendly, sustainable
  • Low-maintenance
  • Economical
  • pH alkaline or neutral
  • Heavy load-bearing
  • Sub-base
  • Easy to lay


MOT Type 3 products are predominantly used in constructing roads, driveways, car parks, and foundations for paving. Its strength and compactability make it an ideal base material for heavy-use areas. Here are many of the common applications:

  1. 1
    Permeable Paving: MOT Type 3 is a popular choice as a sub-base material for various construction projects. It's commonly used for permeable paving systems, providing a stable and well-drained foundation that allows water to infiltrate into the ground.
  2. 2
    Sports Surfaces: It is also suitable for sports surfaces such as tennis courts, sports pitches, and equestrian arenas. It can withstand heavy use and provides good drainage to prevent water-logging.
  3. 3
    Tree Root Protection: MOT Type 3 is frequently used for constructing tree root protection systems. It creates a stable and well-drained foundation that helps to support the weight of the system and allows for proper root growth and water drainage.
  4. 4
    Hard Standings: For creating hard standings, such as areas designed to support heavy loads like vehicles or machinery, MOT Type 3 is a reliable option. Its coarse nature provides stability and load-bearing capacity.
  5. 5
    Paths and Patios: Type 3 MOT can also be used as a sub-base material for paths and patios. It provides a solid foundation for the surface material, reducing the risk of sinking or shifting.
  6. 6
    Drainage Systems: It is suitable for applications where drainage is essential, such as drainage systems. Its coarse nature allows for water to drain freely, reducing the risk of water accumulation and potential damage to the construction.

In the following section, we list common type 3 MOT uses in landscaping. Wherever there is a hyperlink beside an item, an article from Outdoor Aggregates about the topic is available.

Driveway and drain with brick paving slabs

Inspiration and Informational Articles

  • MOT sub-base type 3
  • Landscaping with MOT type 1
  • Sub-base for driveways
  • MOT type 1 pathways

DIY-Friendly How-To Guides

  • How to lay a sub-base 

Need to work out how many stone chippings your  project needs? Try our free gravel calculator.

Tarmac and brick residential road

Unsuitable For

The following list represents the kinds of applications that MOT type 3 may not be suitable for:

  1. 1
    Areas with fine plantings: If you have creepers or low-growing plants in your garden gravel can make it harder for these plants to thrive, as it may interfere with their root systems as they try to grow.
  2. 2
    Play surfaces

Similar Alternatives to MOT Type 3

The following is a list of decorative aggregates which are alternatives to MOT type 3. They may offer you a more suitable variation on the primary colour, a more economical option, or a close substitute for cases where the base material may be unsuitable for the project you are creating, e.g. limestone is not fish-friendly, where granite is.










0-63mm (0.4-2.6")





0-50mm (0.4-2")





0-50mm (0.4-2")



Crushed concrete



0-50mm (0.4-2")



MOT type 1 scalpings



0-50mm (0.4-2")



Under £80







Installing a concrete driveway

Sub-base generally won't require maintenance unless it requires major repairs.

Purchasing Tips

Close up of tarmac and crushed gravel road

If you're purchasing MOT Type 3 for your landscaping project, it is essential to give careful consideration to the quality and source of the material. It is advisable to only purchase certified materials that comply with the required standards. Don't hesitate to ask for compliance documents to ensure that the material is not contaminated which could cause serious problems in the future.

When looking for recycled options, it's important to ensure that they have the required structural integrity. It's always a good idea to compare prices from multiple suppliers of MOT Type 3 and ensure that the delivery options and costs are suitable for your site. Timing of delivery should be taken into consideration to avoid any delays and storage issues. Choosing the right type of MOT Type 3 will guarantee a successful and long-lasting outcome for your landscaping project.

Our MOT calculator is a very useful tool that can provide you with a quick and unbiased estimate of the material requirements for your project based on the measurement of the space. This is one of the most efficient and easiest ways to ensure that you order the correct amount of material, avoiding the risk of shortages or overspending. When you order a MOT type 3 bulk bag or loose loads, it often provides better value than buying smaller quantities. Therefore, accurate calculations are crucial for saving both time and money. Additionally, it is essential to consider the delivery logistics, such as vehicle access to the site.


What is MOT type 3?

MOT type 3 is a type of crushed aggregate commonly used as a sub-base material for construction and roadworks, known for its stability and superior drainage properties.

What is the difference between MOT type 1 and 3?

MOT type 1 has smaller, more compactable particles, making it ideal for a smooth, stable base, while MOT type 3 is larger and more permeable, suitable for areas requiring drainage.

What are the uses of type 3 MOT?

Primarily used as a stable, load-bearing sub-base for roads, driveways, and parking areas, MOT type 3 is also suitable for landscaping projects requiring maximum drainage.

Is MOT type 3 suitable for driveways?

Yes, its load-bearing capacity and drainage properties make it an excellent choice for driveways and other high-traffic areas.

Can type 3 MOT be used for landscaping projects?

Yes, it's suitable for landscaping projects requiring a stable, permeable sub-base.

There are many wonderful types of gravel and aggregates available for your project needs. Check them out!

About the author 

Ben Parrot is a landscape gardener and amateur geologist. He is the founder of Outdoor Aggregates, with the mission to create the first encyclopaedia for decorative aggregates. From natural stone through to decorative bark, these aggregates are critical to garden and landscape design, universally.

The problem: There isn't any place where all the different types of decorative landscaping materials and construction aggregates can be found, nor are the specifications of each type readily available. So, enriched by his extensive experience, and inspired by the timeless elegance and raw beauty of stone and rock, etched by nature's artistry over millennia, Outdoor Aggregates was born.