Platform & edge protection
What is a guard rail?
A guard rail is a horizontal tube along the open edge of a working platform that stops a person falling. A main rail sits at the top, with an intermediate rail below so the gap cannot be fallen through.
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<img src="https://scaffoldoptix.co.uk/glossary/guard-rail/diagram.svg" alt="guard rail — scaffold diagram from ScaffoldOptix" width="880" height="620" loading="lazy">
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<a href="https://scaffoldoptix.co.uk/glossary/guard-rail">What is a guard rail?</a> — diagram by
<a href="https://scaffoldoptix.co.uk">ScaffoldOptix</a>
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</figure>Guard rails are the primary collective fall protection on a scaffold — collective meaning it protects everyone on the platform without anyone having to put anything on or clip anything in. That is why it is preferred over harnesses wherever a platform can be edge-protected.
The arrangement is a main guard rail at the top of the open edge and at least one intermediate rail between it and the toe board, so no unprotected gap is left. Between the toe board, the intermediate rail and the main rail, the edge is closed from the platform surface upwards.
The Work at Height Regulations 2005 set out minimum heights for the main guard rail and maximum gaps between rails. Those are legal minimums rather than design targets, and they are the figures an inspector will measure against.
What goes wrong on site
- Intermediate rails left off, leaving a gap between the toe board and the main guard rail large enough to fall through.
- Guard rails removed at a loading bay and not replaced with an alternative arrangement.
- Rails fitted to the inside face of the standards where the platform is against the building, then removed for access without anything replacing them.