Clay vs. Concrete Pavers: Understanding the Differences

Selecting the ideal paving material is a pivotal decision for any landscaping project, and two popular options often deliberated upon are clay and concrete pavers. Both provide visual appeal and lasting performance. However, to make an informed choice for your project, it's essential to understand the unique characteristics, advantages and disadvantages associated with each material.

This article will explore the key differences between clay and concrete pavers, empowering you to confidently choose the most suitable paving material that combines functionality with visual appeal.

Clay pavers boast a rich legacy dating back centuries. The Romans utilized clay bricks for roads and pathways, a testament to their enduring strength and durability. Throughout history, clay has been favoured for its natural aesthetic and resilience, making it a popular choice for paving applications.

Advantages

1) Visual Appeal: Clay pavers offer a plethora of colours, textures, and shapes that exude a desirable rustic quality. The natural hues of clay deepen over time, enhancing the visual appeal of outdoor spaces.

2) Durability: Clay pavers are known for their longevity. There are many historical sites where the original clay pavers are still in place². They can withstand the rigor of both foot traffic and vehicular traffic, along with weather fluctuations making them an ideal choice for both commercial and domestic projects.

3) Reusability: Clay pavers are reusable and recyclable, they can be turned over and reused¹ or broken down into aggregate to be utilised in another function. Having this capability contributes to a circular economy ethos making them a desirable choice for any project that is championing resource conservation.

4) Colour Fastness: Clay pavers will never fade, as the colour is throughout the entire body of the product due to its material composition and manufacturing process.² The colour of a clay paver will remain the same throughout its entire lifecycle, withstanding erosion and other wearing factors such as UV rays. Another contributing factor to their colour fastness, is the fact that they are fired, this keeps the colour consistency and eliminates the need for excessive maintenance and sealing.

Disadvantages:

1) Cost: Clay pavers are perceived to be more expensive than their concrete counterparts due to the intricate manufacturing process and premium quality of raw materials. However, their long-term durability and timeless appeal justify the initial investment.

2) Installation time: Given the intricate nature of good-quality paver laying, the installation of clay pavers may take a little longer, but good site practises soon eliminate any concerns. However, the finished result and the minimal upkeep required, will make it worth it.  

Concrete pavers emerged during the 1800s as a contemporary alternative to traditional paving materials, gaining popularity for their affordability. As advancements in manufacturing technologies have been made, concrete pavers have become a popular choice for both domestic and commercial projects. 

Advantages:

1) Affordability: Concrete pavers are an attractive option for cost-conscious projects. The mass production process and abundance of raw materials contribute to their competitive pricing.

2) Uniform sizing: As concrete pavers are produced using a mould and are not fired, their shape and size is completely uniform. This is purported to make them faster to install.

Disadvantages:

1) Colour loss: It is widely believed that the colour in most concrete pavers will fade several years after installation.¹ The reason being is that the colour is mixed into the top layer of the pavers, penetrating only a few millimetres into the paver making it susceptible to UV bleaching and surface erosion. There are sealant sprays that can be used. However, they only increase the time before the colour bleaches, they do not fix it in place.

2) Susceptible to Erosion:  Concrete blocks are composed of concrete and aggregate mixed together. They are particularly vulnerable to erosion from the elements which degrades the paver, exposing the aggregate within the paver. A phenomenon known as spalling.² This completely changes the aesthetic of the original paver, creating a lighter and speckled look.

3) Prone to Staining: Due to their porous composition, concrete pavers are susceptible to staining from oils, grease, and other substances.³ This contributes to the degradation of the paver and ultimately detracts from their aesthetic appeal over time.

4) High Maintenance: Given their susceptibility to colour loss, erosion and staining, concrete blocks require a high degree of maintenance. A systematic and proactive approach needs to be taken to maintain them, otherwise they will degrade at a much greater speed. The process should involve sweeping, regular pressure washing and applying a protective coating regularly.⁴ All these steps drive up the maintenance cost of concrete blocks.

Comparing the environmental credentials, particularly the carbon impact, of clay and concrete products is becoming more popular. However, the two types of pavers should not be compared on carbon impact alone, because they each have their place in different projects.

The process of creating clay pavers requires them to be fired using natural gas at temperatures of up to 1000 degrees, which results in a higher Global Warming Potential (GWP) figure for the A1-A3 section of a Lifecycle Assessment (LCA). This is the section of the LCA that covers the raw material extraction, transport of materials to the manufacturer and the manufacturing process. However, this figure is mitigated by the clay pavers long life span (125 years) and reusability.

Conversely, concrete pavers do not require firing. Concrete pavers are cured at around 10-30^oC¹so the A1-A3 GWP figure tends to be lower. However, concrete pavers often have a shorter service life (50 years) compared to clay products.

Alongside the embodied carbon impact, the decision-making process should be influenced by the proposed lifespan of the project; how durable the pavers need to be; and how the paving will be maintained in the long term.

Clay pavers are durable, retain their colour and have a long service life at 125 years¹. All these factors mitigate the higher upfront cost and carbon impact of the paver since you should not need to replace them for over a century. Clay pavers can withstand high traffic footfalls and the colour will not fade over time, making them perfect for the use in commercial projects or domestic applications.

In contrast, concrete pavers have a low upfront carbon cost but a shorter service life of 50 years⁸. Concrete pavers are more susceptible to erosion so when used in projects that will have high footfalls, this can result in spalling. When this is combined with their relatively short service life; it increases the frequency of replacement if used in public or commercial projects. The colour and surface texture of concrete pavers will change over time, so maintenance requirements or replacement could undermine the low upfront cost and carbon impact.

Choosing the Right Paving Material for Your Project

Ultimately, both clay and concrete pavers offer viable options for environmentally conscious landscaping. There is no right answer for everyone but there is a right answer for each type of project. The questions you need to consider are:

1) Are you selecting pavers for a domestic, commercial, or public space?

2) How will the space be used?

3) What is the anticipated lifespan of your landscaping project?

4) What is your upfront budget?

5) Who will be responsible for maintenance and how will it be funded?

6) How important are long term aesthetics?

7) How often do you want to have to replace the pavers?

By weighing up the different attributes of clay and concrete pavers through these questions, you can make an informed decision that aligns with your project vision and values. Whether creating a courtyard at home or an urban plaza, the right paving material sets the foundation for the landscape and influences people’s experience of a place.