Australian Standard AS1657-2018

Definition 

Guardrail is to provide edge protection at the edge of a floor,  platform or walkway. Handrail is rail that provides a handhold on a platform, walkway, stairway or step ladder. Guardrail can be designed to be suitable for use as a handrail.

General dimensions

• The height of a handrail above the floor or the nosing of a stair tread, shall be between 900mm and 1100mm. Where fall from height is significant it is recommended to increase the height of the guardrail to at least 1000 mm.
• Where circular metal handrails are provided, external diameter shall be 30mm to 65mm.
• Where square or rectangular handrails are provided, the sum of height and width shall be 70 mm to 100mm.
• Unrestricted movement of the user’s hand along the upper surface with a minimum hand clearance of 50mm, with no sharp edges or other features that could cause injury to the user.
• Guardrailing  shall consist of a top rail and a knee rail both parallel to the floor, walkway or platform. Distance between the knee rail and the floor to be ≤ 560mm. Where toeboards are used the distance between the knee rail and top of the toeboard to be ≤ 450mm

Toeboard or Kick plate

• A toeboard shall be installed if there is gap greater than 10mm from a permanent structure. Or if falling objects creates a hazard to personnel accessing the area below.
• Any gap between the underside of the toeboard and the walkway surface shall be within 10mm. The top of the toeboard shall be minimum 100mm above the floor.

Load ratings

• Guardrails shall be designed to sustain a single acting force of 600 N or 350 N/m acting outwards or downwards at any part of the system. No part of the system shall deflect elastically by more than 100mm under the imposed load.
• Other loads to be consider when designing the system are forces imposed by wind loading.
• Any part of the toeboard shall withstand a horizontal force of 100N, with no elastic deflection greater than 30mm and no gap greater than 10mm to be exposed between the inside face of the toeboard and the edge.