Roofing involves several tasks that potentially expose persons to the risk of falls both through and from the edge of the roof structure. Physical edge protection must be provided for all roofing works so far as is reasonably practicable.

Proper edge protection and scaffolding helps businesses meet legal requirements and protects workers from severe injuries or fatalities. Whether installing, repairing or maintaining a roof, secure temporary edge protection systems provide a safer working environment. Failure to implement these systems can result in legal penalties and increased liability for site managers.

The pitch of the roof is one of the key risk factors to be considered when determining the type of risk control measures to be put in place for roofing work. The critical angle refers to the maximum roof pitch at which workers can safely walk and perform tasks without additional fall protection. Builders and subcontractors should determine the critical angle as part of their risk assessment.

In no case should the critical angle be taken as greater than 26 degrees or 10 degrees where the presence or likelihood of surface moisture, oil or other conditions makes the roof slippery. Consideration should be given to the fact that the critical angle may be reduced in the presence of fully glazed and wet tiles.

Safe access must be provided for workers carrying out work on the roof. Depending on the edge protection system being used, you should ensure that personnel can access the roof through the roof edge protection without having to climb over the top rail or mid-rail. Moreover, you must also verify that:

• Access ladders are secured against movement
• If a platform exceeds 500 mm below the roof edge, an additional access method is provided.
• Elevators, hoists or similar equipment are installed to safely deliver materials directly to the roof level.

Roof safety rail systems should include top, mid and bottom rails or toe boards (see Figure 22). If toe boards are used in place of bottom rails, they must be able to withstand the likely impact loads. Guardrail systems should include the following:

• Toe boards or mesh infill to prevent tools, materials or debris from falling from the roof unless a 2 metre ‘no go’ zone has been established to prevent persons from entering the area below.
• A clear gap between rails not exceeding 450 mm. The clear distance between a mid-rail and a toe board or bottom rail should not exceed 275 mm.
• There is no gap between the roof edge, including the gutter and a guardrail outside the roofline exceeding 100 mm.
• A clear distance between the roof cladding and the bottom rail of not less than 150 mm and not greater than 275 mm.
• An effective guardrail height above the roof surface of not less than 900 mm (for roofs with a pitch over 10 degrees, the effective height must be measured from a point 300 mm inside the roof edge)
• Infill panels where the pitch of the roof exceeds 26 degrees.