Australian WHS Roof Work Requirements

In Australia, falls during roof work are controlled under the harmonised Work Health and Safety (WHS) laws and supporting codes of practice published by Safe Work Australia and adopted by states and territories. The Preventing Falls in Housing Construction Code of Practice gives detailed, practical rules for residential roofing. Some states and territories publish their own versions, so the local regulator's code should be checked.

Hierarchy of control

The code sets five levels of control for fall risks:

1. Eliminate the risk by doing work on the ground or a solid construction.
2. Fall prevention devices, such as guardrails and catch platforms. Guardrails are the main form of edge protection for roofing.
3. Work positioning (travel restraint), which stops a worker reaching an edge.
4. Fall arrest systems, used only where higher controls are not reasonably practicable.
5. Administrative controls and ladders, used only for remaining risk; ladders are mainly for access and short, light work.

Edge protection details

• Physical edge protection should be provided for all roofing work so far as reasonably practicable.
• Guardrails should have top and mid rails and toeboards or mesh, with the top rail at least 900 mm above the roof surface and gaps between rails no more than 450 mm.
• Guardrails outside the roof line should leave no more than 100 mm between the roof edge (including gutter) and the rail.

Roof pitch thresholds

• Workers may walk and work on roofs below the critical angle, which should never exceed 26 degrees, or 10 degrees on slippery surfaces.
• Catch platforms are set no more than 1 m below the edge on roofs of 26 degrees or less, and no more than 500 mm below on steeper or slippery roofs, with infill panels above 26 degrees.
• Roofs steeper than 35 degrees are treated as unsuitable to stand on even with edge protection; workers need at least two of a work positioning system, a roof ladder or a scaffold platform at the edge.

Harness systems

Travel restraint anchors on metal or tiled roofs may be used for short tasks. The code notes that fall arrest has limited use in housing construction, being generally suited to work above about 6.5 m, and that achieving a 15 kN anchorage on a timber roof is often difficult; any fall arrest use needs a rescue procedure.