Scaffold Edge Protection: Guardrails, Toeboards and Brick Guards — NASC SG4:22 Requirements

Quick Answer: Under Work at Height Regulations 2005 Schedule 2 and NASC SG4:22, scaffold working platforms require a top guardrail at minimum 950mm above the platform, an intermediate guardrail positioned so no gap exceeds 470mm, and a toeboard of at least 150mm height. Brick guards (mesh infill panels) are required where materials could fall onto people below — particularly over pedestrian routes.

Summary

Edge protection on scaffolding is not optional — it is a legal requirement under the Work at Height Regulations 2005 and is specified in detail in NASC SG4:22 (Preventing Falls in Scaffolding and Falsework). The purpose is twofold: to prevent operatives from falling off the platform edge, and to prevent materials and tools from falling onto people below.

The standard three-component edge protection system — top guardrail, intermediate guardrail (or infill panel), and toeboard — has been the UK industry standard for decades. SG4:22:2022 introduced updated requirements on advance guardrail installation (fitting the top rail before stepping onto the newly erected lift level) which changed erection practice significantly.

Understanding edge protection requirements matters to scaffolding contractors, site managers, and every trade that works on scaffolding. Removing, displacing, or modifying guardrails is a compliance breach and one of the most frequent WAH Regulations enforcement actions taken by HSE inspectors.

Key Facts

Quick Reference Table: Edge Protection Requirements

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Component Minimum Specification
Top guardrail height 950mm above platform surface
Intermediate rail gap No gap >470mm above or below
Toeboard height 150mm minimum
Guardrail horizontal load capacity 0.74 kN/m
Brick guard mesh size Maximum 50mm × 50mm recommended
Debris net aperture Per EN 1263-1 (typically <100mm)
Inner edge gap requiring protection >150mm from wall face

Detailed Guidance

Guardrail Configuration

The standard UK scaffold guardrail configuration:

        ← min 950mm →
Platform │     TOP RAIL (≥950mm above platform)
  ↑      │     (gap ≤470mm)
  │      │     MID RAIL
  │      │     (gap ≤470mm above toeboard)
  │      │     TOEBOARD (≥150mm)
Platform surface

Where the top rail is set at 950mm, and the intermediate rail positioned such that neither the gap from platform-to-mid-rail nor mid-rail-to-top-rail exceeds 470mm:

Note: Many firms set the top guardrail at 1050mm or above as a matter of good practice — this is compliant and reduces the risk of an operative overbalancing over the rail.

Advance Guardrail Systems — SG4:22:2022 Requirement

NASC SG4:22:2022 (and its predecessor SG4:15) requires that the guardrail for a new lift is installed before the scaffolder steps onto that lift. This is achieved by:

This represents the application of the WAH hierarchy: collective protection (the guardrail) is installed before the person is exposed to the risk. The "old" practice of erecting a lift without guardrails and then fitting them while exposed is not compliant with SG4:22.

For dismantling, the same principle applies in reverse: guardrails are the last component removed, not the first.

Toeboards

Toeboards (also called kickboards or toe boards) prevent materials, tools, and waste falling off the platform edge. Requirements:

Common omissions or defects:

Brick Guards and Debris Netting

Brick guards are rigid mesh panels fitted to the face of the scaffold guardrails. They prevent small items (brick fragments, screws, mortar, tools) from passing through the guardrail gap and falling. Requirements:

Debris nets (also called containment nets or safety nets) are installed across the entire scaffold face or below scaffold platforms. They are required for:

Debris nets are specified in EN 1263-1 (Safety Nets — Safety requirements, test methods). Standard nets have mesh aperture ≤100mm. Net design, attachment, and inspection by competent person is required.

Scaffold Fans (Overhead Protection)

A scaffold fan is a projecting horizontal platform extending from the scaffold out over the public footway below, providing overhead protection from falling objects. Requirements:

Local authority (highways authority) scaffold licence conditions often specify fan requirements. Always check licence conditions before erection.

Inner Edge Protection

Often overlooked: if the inner edge of the working platform (closest to the building) has a gap of more than 150mm between the boards and the building face, inner edge protection may also be required. This is common when:

WAH Regs Schedule 2, paragraph 4 addresses this. The 150mm limit is not explicitly stated in the Regulations but is widely adopted as the practical threshold below which the gap is not considered a significant fall risk.

Frequently Asked Questions

Can other trades remove guardrails to make it easier to load materials?

No. Only the scaffolding contractor may modify or remove guardrails, and only when there is a safe system of work in place (typically with edge restraint, harnesses, or a temporary barrier). Any trade that removes a guardrail without scaffolding contractor involvement is in breach of the Work at Height Regulations and assumes liability for any subsequent incident.

Does the top guardrail have to be a full tube, or can a proprietary rail system be used?

Either is acceptable, provided the rail meets the load capacity requirement (0.74 kN/m horizontal) and height requirement (≥950mm). Many proprietary guardrail systems use mesh infill or folding panels. These must meet BS EN 13374 (temporary edge protection — performance requirements, test methods) or the equivalent load requirement via calculation.

Are brick guards required on all scaffolds?

No — only where there is a risk of materials falling onto people. A scaffold around a domestic rear extension with no public access below may not require brick guards. A scaffold on a busy high street at height, used for masonry work, definitely does. The risk assessment for the project should determine whether brick guards are required. Local authority licence conditions may impose them regardless of the formal risk assessment.

What is the difference between a brick guard and a debris net?

A brick guard is a rigid or semi-rigid mesh panel fitted to the guardrail of the working platform, preventing items passing through the rail gap. A debris net is a softer net system installed across the full face of the scaffold or below platforms, designed to catch falling items over a larger area. Brick guards are simpler and more common; debris netting is used on larger refurbishment projects with significant facade debris generation.

Regulations & Standards