Guardrail Systems

A compliant guardrail system has:

• A top rail 42 inches (plus or minus 3) above the walking surface.
• A midrail about halfway up, around 21 inches, when there's no wall or equivalent below the top rail.
• A toeboard (at least 3.5 inches) where tools or material could fall on someone below.
• Enough strength to take a 200-pound force in any outward or downward direction on the top rail without dropping below 39 inches.

If a rail flexes below 39 inches under that push, it's not protecting anyone — it just looks like it is.

• Guard every open side and edge 6 feet or more above a lower level.
• Cover openings and holes with guardrails or a secured cover.
• Surfaces must be smooth enough not to cut hands or snag clothing.
• Banding is not a top rail; wire rope used as a top rail must be flagged and kept tensioned.

A guardrail only works if it stays up and complete. The common failures:

• A section removed for a material delivery and never put back.
• A gap at a ladder or hoist point left unguarded.
• Material leaned or stored against the rail so it can't take the load.
• Sitting, standing, or climbing on the rail.

If you remove part of a guardrail to move material or reach a point, that edge is now unprotected — anyone working there needs personal fall arrest until the rail goes back. Put it back the moment the task is done. Most guardrail-related falls are through a gap someone meant to close later.