BRE470 is the UK industry standard for designing working platforms for tracked plant. Understanding this guidance is essential for every piling contractor, temporary works coordinator, and site engineer.
Introduction to BRE470
BRE470, formally titled "Working Platforms for Tracked Plant: Good Practice Guide to the Design, Installation, Maintenance and Repair of Ground-supported Working Platforms" and published by the Building Research Establishment (BRE) in 2004, is the definitive UK guidance document for the design of working platforms for tracked plant such as piling rigs, cranes, and drilling equipment.
The document, commonly referred to as BR 470, provides a systematic calculation methodology for determining the required thickness of granular working platforms placed on natural ground to safely support heavy tracked plant. It addresses both cohesive (clay/silt) and granular (sand/gravel) subgrade conditions and includes provisions for geosynthetic reinforcement.
Before BRE470, there was no standardised approach to working platform design in the UK. Contractors and designers relied on experience, rules of thumb, and ad hoc calculations that varied widely in quality and reliability. The publication of BR 470 brought consistency, safety, and professional rigour to an area of temporary works that had historically been under-engineered.
Why BRE470 Matters for Piling Contractors
For piling contractors, BRE470 is not optional guidance — it is the expected standard of care. The Health and Safety Executive (HSE) and the Temporary Works Forum both reference BR 470 as the benchmark for working platform design. Failure to design platforms in accordance with this guidance exposes contractors to significant risks:
Safety risks: An inadequately designed working platform can fail under the weight of a piling rig, leading to rig instability, toppling, or ground collapse. These incidents can cause serious injury or death to operatives and bystanders. The Federation of Piling Specialists (FPS) has documented numerous incidents where platform failure led to rig overturning.
Legal and regulatory risks: Under the Construction (Design and Management) Regulations 2015 (CDM 2015), the principal contractor has a duty to ensure that working platforms are designed and maintained to be safe. A platform that fails because it was not designed to BRE470 would be difficult to defend in any HSE investigation or civil claim.
Commercial risks: Platform failure causes project delays, equipment damage, and potential claims from third parties. The cost of a properly designed platform is negligible compared to the cost of a rig recovery, project delay, or personal injury claim.
Professional reputation: Clients, principal contractors, and temporary works coordinators increasingly require BRE470 compliance as a contractual condition. Contractors who cannot demonstrate compliance risk losing work to competitors who can.
The BRE470 Calculation Methodology
The core of BRE470 is Appendix A, which provides the step-by-step calculation methodology for determining platform thickness. The calculation considers:
Subgrade conditions: The natural ground beneath the platform is characterised by either undrained shear strength (cu) for cohesive soils or angle of shearing resistance (φ') for granular soils. These parameters are typically obtained from ground investigation data.
Platform material properties: The granular fill used to construct the platform is characterised by its angle of shearing resistance (φ'p) and unit weight (γp). Well-graded crushed rock typically has φ'p values of 40-45°.
Plant loading: The track pressures from the piling rig are the primary design load. These are expressed as maximum track pressure (q1k) under outrigger loading and slewing track pressure (q2k). EN 996 provides standardised track pressure data for common piling rigs.
Partial factors: BRE470 applies partial factors to both loads and material properties to achieve a safe design. The load factor (γF) is typically 1.26, and the material factor (γM) is applied to the tangent of the angle of shearing resistance.
The calculation determines the required platform thickness (T) such that the bearing pressure at the base of the platform, spread through the granular fill at an angle related to φ'p, does not exceed the bearing capacity of the subgrade.
Who Needs to Understand BRE470?
Several key roles in the construction industry need a working knowledge of BRE470:
Temporary Works Coordinators (TWCs): Under BS 5975, the TWC is responsible for ensuring that all temporary works, including working platforms, are properly designed, checked, and approved before use. The TWC must understand BRE470 to review and approve platform designs.
Temporary Works Designers (TWDs): The designer who produces the platform calculation must be competent in the BRE470 methodology. The design must be checked by an independent checker before it can be approved by the TWC.
Piling contractors: The contractor installing the piling rig is typically responsible for providing the platform design. They must understand the input parameters required and ensure the platform is constructed in accordance with the design.
Site engineers and agents: Those responsible for day-to-day site operations must understand the platform design requirements, monitor platform condition during use, and ensure maintenance and repair are carried out as needed.
Principal contractors: Under CDM 2015, the principal contractor has overall responsibility for site safety, including the adequacy of working platforms.
How Our BRE470 Design Tool Helps
Our BRE470 Piling Mat Designer automates the Appendix A calculation methodology, making it accessible to piling contractors and temporary works professionals without the need for expensive consultancy. For just £299.99 per design, you receive:
A full interpretive design with all BRE470 Appendix A calculation steps clearly presented, a professional check certificate with unique reference number signed by David Miller (Temporary Works Designer), a cross-section diagram showing the platform layers and dimensions, and instant digital delivery in a print-ready A4 format.
The tool includes 23 pre-loaded piling rigs from Liebherr, Bauer, and Soilmec with EN 996 track dimensions auto-filled, supports both cohesive and granular subgrades, and includes optional geosynthetic reinforcement.
Traditional consultancy designs cost £500–£1,000 per design and can take days to receive. Our tool delivers the same professional output in under 2 minutes at a fraction of the cost.
