MOT Type 1 and MOT Type 2 are both granular sub-base aggregate materials commonly used in construction and roadworks. The hardcore sub-base is commonly used underneath concrete slabs for roads, pathways, or any other construction that requires a firm base. Although used similarly, each of the two has very distinct differences in composition and areas of application.

So, what exactly is the difference between MOT Type 1 and Type 2, and which is best for your project? Let’s unpack both of these types of aggregates and better understand their uses.

Sub-base aggregate: MOT Type 1

MOT Type 1 is the most widely used sub-base material in construction made from crushed stone, gravel, and recycled materials such as concrete or limestone.

In terms of particle size, MOT Type 1 is generally sized from 40mm down to dust. This means that this particular aggregate includes fine particles for better compaction.

MOT Type 1 uses:

It is ideal for sub-base layers in:

• Driveways
• Patios 
• Pathways
• Roads
  

It is also often used underneath tarmac, concrete, and paving slabs to prevent shifting and sinking.

Key features of MOT TYPE 1:

• Due to the high compaction rate, MOT Type 1 aggregate creates a dense and solid sub-base.
  
• Due to its strength, it has an excellent load-bearing capacity and is often used for road construction as it ensures that surfaces remain level and durable over time.

Sub-base aggregate: MOT Type 2

MOT Type 2 is quite similar to Type 1, but it has a higher proportion of finer materials, and its composition is made with less sharp stone. It has more clay and silt content, making it far less stable than MOT Type 1.

MOT Type 2 uses:

MOT Type 2 has a range of different uses, particularly in areas that require better drainage, where less compaction is necessary, or in lighter load-bearing areas. Such as:

• Footpaths and walkways
• Light-load or private driveways that are built using softer driveway aggregate [link to “How to Choose the Right Gravel for Your Driveway” blog], such as gravel
• Landscaping
• Garden sheds
• Greenhouses
• Stables

Key features of MOT Type 2:

• MOT Type 2 contains more fines (or smaller particles) and, therefore, will be looser than Type 1.
  
• MOT Type 2 allows for better water drainage due to its slightly looser composition. It makes for a better option in areas that are prone to flooding or waterlogging.
• It is ideal for garden areas or landscaping projects where excess water might need to be absorbed.

All things considered, it is safe to say that MOT Type 2 is suitable for softer ground or drainage-friendly sub-base areas. This includes gardens or rural paths, whereas Type 1 may not compact well under those conditions.

MOT Type 1 vs MOT Type 2

MOT Type 1 and MOT Type 2 both have very specific purposes and uses. Depending on your project and your environment, you might need one or the other. In other cases, you might need both. For instance, you might need MOT Type 1 for a heavy-duty driveway or road, while you might need MOT Type 2 for a landscaping project in your backyard.

To sum up, here are the key features of MOT Type 1 and MOT Type 2:

Comparison of MOT Type 2 vs. MOT Type 1 for different uses:

In conclusion, MOT Type 1 is the go-to for high-strength sub-base applications, while MOT Type 2 is more suitable where drainage might be a concern or where a lighter-duty base is needed. If you need an expert’s advice on your building project, contact our aggregate experts, who are waiting to help you.