Sense and Safety Using Reinforced Engineered Pavers for Pedestal Paving

Pedestal paving is becoming an increasingly popular method of paving for both interior and exterior applications across residential and commercial spaces. Rather than fixing pavers directly to the substrate as in traditional methods, pedestal paving is installed on raised platforms (pedestals) which can sit anywhere up to 900mm above the subfloor. This offers numerous benefits versus traditional paving methods by creating level paved surfaces that still offer excellent drainage, allowing designers and specifiers to create elevated spaces for functional, or purely aesthetic reasons.

However, pedestal paving can pose a danger to public safety if not installed using suitable materials. If a paver is fractured or cracks due to an impact load, a person may fall through the pavement which could result in serious injury. There is currently no Australian Standard that specifies the requirements for pavers in pedestal applications, and the existing strength requirements for pavers installed using the traditional method may not be sufficient. This means that it is of the utmost importance that specifiers choose suitable, highly impact resistant pavers for any pedestal paving applications.

Reinforced engineered pavers are an ideal material choice for pedestal paving. They are designed specifically to mitigate the inherent safety risks of pedestal paving by offering superior strength and impact resistance, and are manufactured to maintain structural integrity even when cracked.

This whitepaper will provide a discussion of the benefits and issues related to pedestal paving and look at how reinforced engineered pavers can provide a safe, effective and sustainable option for pedestal paving applications.

Introduction

There is currently no Australian Standard that specifies the requirements for pavers in pedestal applications, and the existing strength requirements for pavers installed using the traditional method may not be sufficient.

Pedestal paving has rapidly gained popularity in recent years as it has provided a simple, cost effective means of overcoming many of the issues posed by traditional paving methods. Pedestal paving installation involves the placement of pedestals as a support mechanism onto a sub-base. The matrix of pedestals is determined by the size of the paving modules. The pedestals are adjustable, to compensate for any irregularities in the subbase and any gradient for drainage. The paving units are then placed directly onto the pedestals, rather than onto the subfloor as in traditional installations. This allows the pavers to be laid quickly and effectively, eliminating a number of the inefficiencies of traditional paver installation in the process.

Pedestal paving provides added flexibility to architects and designers when designing paving installations. The raised installation of pedestal paving means that pavers do not need to be glued to waterproofing membranes in balcony, basement or rooftop applications. Services and wiring can be run through the void between the pavers and sub-base, potentially saving large amounts of time, money and effort in the installation of these elements throughout the project. Similarly, the costs of installing pedestal pavers are drastically less than installing in the traditional method. As previously mentioned, removing the need to grade the pavers for drainage purposes makes installation a much simpler process. In addition, pedestal installations do not require grouting, resulting in a cleaner overall look and eliminating the unsightly effects of grout haze.

From an accessibility standpoint, pedestal paving can provide a simple method of creating accessible spaces, either in new builds or as a retrofit. The 2010 Disability (Access to Premises) Standards, referencing AS 1428.1 - Design for Access and Mobility - Design for access and mobility-General requirements for access codifies in law the requirement for continuous accessible paths of travel within Class 1b-9 buildings,1,2 where a continuous path of travel is “An uninterrupted path of travel to, into or within a building

providing access to all required accessible facilities”.3 Pedestal paved areas can be raised to meet thresholds, creating flush, wheelchair-friendly access to spaces.

Material Safety and Pedestal Paving

If correct materials are chosen and installed correctly, pedestal paving is entirely safe, offering additional safety benefits not possible with traditional paving methods as described above. However, due to the raised profile of the paving modules, there is a danger that any fractured pavers could break completely, causing pedestrians to fall through to the sub-base.

Depending on the height of the pedestals - which can be up to 900mm - this could cause serious injury. For that reason, it is imperative that pavers of sufficient strength and impact resistance are selected for pedestal installations.

There is currently a regulatory gap in Australia when it comes to the specification of pavers for pedestal installation applications. The flagship standard for concrete and stone pavers is AS/NZS 4456 - Masonry units and segmental pavers and flags, and of particular relevance are parts 4 and 5, which sets out the methods of test and requirements for the breaking load of pavers.4 In line with the standard, the minimum characteristic breaking load for pavers (minimum 40mm thickness) is 2kN - or roughly 202kg. For flags, where a flag is defined as a large format solid paver larger than 400mm x 200mm, the minimum characteristic breaking load is 5kN or roughly 510kg (most pavers used in contemporary landscape applications would be classified as flags). However, this standard assumes that pavers will be set on a solid sub-base and this measure is thus more of an indicator of compressive strength requirement.5

In contrast, pavers used in pedestal paving applications require a high flexural strength and high impact resistance in order to provide adequate safety for pedestrians, as most of the paver span will be unsupported.

Pedestal Paving: A Timely Innovation

Services and wiring can be run beneath pedestal paving, saving time during installation and allowing easy access for future maintenance.

Reinforced engineered paving is a man-made mixture of crushed natural stone types bound together with an adhesive - most often polymer resin or cement mix - that offers a high flexural strength alternative to natural stone. Engineered paving was originally created as a means of overcoming some of the material limitations of natural stone, and can be manufactured in a wide range of colours, sizes and thicknesses to suit any contemporary design aesthetic. Engineered pavers retain all the qualities of traditional pavers in relation to texture and style.

Engineered products are further strengthened by the inclusion of reinforced steel mesh. By inserting a galvanised precast mesh into the paver, the paver’s strength is significantly increased. Importantly, in addition to increasing the flexural strength and impact resistance of the paver, the mesh reinforcement will prevent the paver from failing even if it cracks, creating greater safety and increased durability.

Another benefit of using engineered paving that is locally made and uses locally sourced raw materials, is the reduction of environmental impacts which is not possible with products sourced from overseas. By sourcing stone from local quarries and other raw materials from Australian suppliers, the carbon footprint related to transportation and delivery is minimised and the need for international transit is eliminated. In addition, the processing of Australian raw materials is heavily regulated, meaning that all suppliers must conform with the strict requirements and laws related to mining domestically.

As a material, engineered paving is highly durable, reducing the need for premature replacement or excessive production. It is also recyclable, which means that when sourced from sustainable, production waste minimisation-focused suppliers, it can be a significant contributor to the domestic circular economy, providing better environmental outcomes overall.

Reinforced Engineered Paving: An Ideal Material for Pedestal Paving

Engineered products are further strengthened by the inclusion of reinforced steel mesh. By inserting a galvanised precast mesh into the paver, the paver’s strength is significantly increased.

Anston is the only Australian supplier to offer a reinforced engineered paver designed specifically for pedestal paving applications, which features a sturdy, galvanised steel framework within the body of the paver. This is ideal for pedestal paving for two reasons. First, it significantly increases the flexural strength and impact resistance of the paver. Second, should the paver crack, the steel mesh will maintain the structural integrity of the block and prevent it from splitting.

The product is developed to exceed the strength requirements in existing Australian Standards in order to provide the best possible safety for pedestrians and peace of mind for specifiers and construction industry professionals in pedestal paving applications.

Anston’s pedestal pavers are available precast in more than 50 sizes and 25 colour and finish options with customisation also possible on request. Engineered paving has lower thermal conductivity than most natural stone products, making them cooler to the touch than many natural stone types.

Anston is committed to sustainability through the use of locally sourced natural stones and raw materials, the creation and proper disposal of recyclable products and a manufacturing operation focused on waste minimisation.

Anston Architectural Products

anston.com.au

All information provided correct as of July 2020

REFERENCES

1 Australian Government. “Disability (Access to Premises — Buildings) Standards 2010”. Federal Register of Legislation. Published 15 March 2010. Accessed 17 June 2020. https://www.legislation.gov.au/Details/F2010L00668

2 Standards Australia. “AS1428.1-2009 Design for access and mobility-General requirements for access - New building work”. Accessed 17 June 2020. https://www.standards.org.au/standards-catalogue/sa-snz/building/me-064/as--1428-dot-1-2009

3 Australian Government. “Committee ME-064—Access for People with Disabilities Australian Standard Design for access and mobility Part 1: General requirements for access—New building work”. Accessed 17 June 2020. https://www.aph.gov.au/Parliamentary_Business/Committees/House_of_Representatives_Committees?url=laca/disabilitystandards/exhibits/exhibit09.pdf

4 Standards Australia. “AS/NZS 4456.5:2003 - Masonry units and segmental pavers and flags - Methods of test Determining the breaking load of segmental pavers and flags”. SAI Global. Accessed 17 June 2020. https://infostore.saiglobal.com/en-au/Standards/AS-NZS-4456-5-2003-116256_SAIG_AS_AS_243000/

5 Stone Initiatives. “Choosing the ‘right stone’ for the job”. Accessed 17 June 2020. http://stonemtg.com.au/choosing-the-right-stone-for-the-job.html