OHS Code Explanation Guide

Published Date: July 01, 2009
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Part 22 Safeguards

Section 315 Guardrails

Figures 22.15 and 22.16 show guardrails that meet the requirements of this section. Wire rope or other similar material can be used for the horizontal top or intermediate member as long as it

(a) has a nominal diameter or thickness of at least 6 millimetres (¼ inch) to prevent cuts and lacerations, and
(b) is under tension to minimize sag – unloaded sag should be no more than approximately the span length between tensioning devices divided by 60, and the lowest portion of the wire rope must not be less than the required minimum heights above the working or walking surface.

If wire rope or a similar material is used as the horizontal top member, it must be flagged at intervals of at least 1.8 metres (6 feet) with highly visible material so that the wire rope or similar material can be seen.

Figure 22.15 Guardrail specifications

Figure 22.16 Examples of acceptable guardrails

With temporary guardrails, the intermediate horizontal member can be replaced with a substantial barrier such as a wire mesh or solid panel (see Figure 22.17). The alternative must be a substantial barrier that, when positioned and secured between the top member, toe board, and vertical members, will prevent a worker from falling through the space.

Figure 22.17 Wire mesh used as midrail

An often asked question is “How strong should a guardrail be?” As a general guide, a guardrail should be capable of withstanding a force of at least 890 newtons (200 pounds-force) applied within 5 centimetres (2 inches) of the top edge in any outward or downward direction. The guardrail can bend but must not break or separate (dislodge) from the structure to which it is attached.