Which block paving laying patterns should you use for each traffic category?

There are many block paving laying patterns that can be used to help achieve specific aesthetic project goals. However, the patterns must be suitable to withstand the use and loading associated with each traffic category. 

Each traffic category describes the type of traffic which a paved area, whether block paving,  paving slabs or permeable paving are used, will be subjected to. This ranges at one end of the scale to areas that are used only by pedestrians and cyclists (category 1) through to roads that are used by a high number of commercial vehicles (category 9).  

Traffic category areas where vehicles of any type could travel across block paving areas will always require some type of interlocking pattern. For example, 45° herringbone or 90° herringbone. The extra robustness offered by an interlocking block paving pattern helps ensure that the blocks are not moved out of position by the action of vehicles moving, turning, and braking over the area.   

Another factor to consider when choosing the most suitable block paving laying pattern is whether the paving is bound or unbound. In bound paving, the blocks are held together by mortar to create a rigid construction on the surface. The blocks in unbound paving do not use mortar so they form a more flexible construction, relying on their interlocking installation rather than a binder to hold them together. Consequently, suitable laying patterns for each traffic category must also consider whether the blocks are bound or unbound. 

We will cover all these factors in this blog, and we will start by first looking at the definition of each traffic category. 

What are the traffic categories for bound and unbound block paving? 

The traffic categories that are used for bound and unbound block paving are covered by the standard BS 7533-101 ‘Pavements constructed with clay, concrete, or natural stone paving units – Code of practice for the structural design of pavements using modular paving units’. 

The following traffic category table applies to bound block paving: 

Once the traffic category for the area of paving has been identified, the next step is to decide on the most suitable block paving laying pattern based on your choice of either bound or unbound paving. 

What block paving laying patterns are suitable for traffic categories when using bound and unbound paving?  

Here are the maximum traffic categories for ​​typical laying patterns:  

Examples of block paving laying patterns

Always check with the manufacturer to check their recommendations on the block paving laying patterns suitable for their products based on traffic category.   

What are the traffic categories and block paving laying patterns for permeable paving? 

The traffic categories for permeable paving are different to those we have looked at for bound and unbound paving. Although permeable paving is itself classed as unbound paving, it is covered by different part of the same British Standard: BS 7533-13 ‘Pavements constructed with clay, natural stone or concrete pavers – Guide for the design of permeable pavements constructed with concrete paving blocks and flags, natural stone slabs and setts and clay pavers’. 

The block paving laying patterns will be in line with those of unbound paving. 

Stretcher bond – can only be used for Categories A and B. 

Herringbone – must be used for categories C, D, E and F. 

However, once again, always check with the manufacturer of the permeable paving for their recommendations prior to commencement of design and installation. 

What is the importance of the subbase in relation to traffic categories laying patterns? 

The subbase provides the foundation for block paving, and it must be specified and installed correctly if the chosen block paving laying pattern is to provide the robust support required to meet the demands of each traffic category.  

The depth of the subbase and materials required will depend upon factors such as the traffic category, the strength of the sub-grade and whether a permeable or non-permeable system is required.  

Where can I find more information on block paving laying patterns and traffic categories? 

Tobermore has extensive experience in supplying block paving and permeable paving in laying patterns to meet the requirements of all traffic categories. 

To ensure that all the elements of block paving are present to deliver durable, robust and high-performance paved surfaces, Tobermore offers a free subbase specifier tool.  

Craig McBride, Tobermore’s Technical and Product Training Manager, comments:

“We understand the importance of considering all the key elements that make up a block paving solution. Our subbase specifier tool makes it simple for our customers to get an initial design that will help them deliver a robust and aesthetically pleasing Tobermore block paving solution in a laying pattern that meets each traffic category.” 

If you have any questions about our block paving and permeable paving solutions, please contact our sales team who will be happy to guide you through the choices available for your project.