Overview

In March 2021, a worker suffered serious injuries when he fell approximately six metres through a roof after walking on an old skylight panel that had previously been covered. It appears the void cover plate was held in place by pop rivets. These findings are not confirmed, investigations are still ongoing.

Safety issues

Falls, particularly falls through roofing, are a major cause of workplace deaths and serious injuries. The risk from a fall depends on whether fall control measures are implemented, the height involved and the surface directly below the work area. There may be additional risk when working on or near fragile roof surfaces. Roofs are likely to be fragile if they are made with:

• asbestos roofing sheets

• poly carbonate sheets (alsynite) or plastic commonly used in skylights

• fibre cement sheets

• liner panels on built-up sheeted roofs

• metal sheets and fasteners (especially when corroded).

Before commencing any work on a roof or at height, all surfaces must be inspected to identify any potentially fragile spots. All locations and tasks which could lead to a fall should also be identified. This includes access to areas where the work is to be done. Close attention is required for tasks:

• on any structure or plant being constructed or installed, demolished or dismantled, inspected, tested, repaired or cleaned

• on a fragile surface (for example, poly carbonate or cement sheeted roofs, rusty metal roofs, fibre glass sheeting roofs and skylights)

• on a sloping or slippery surface where it is difficult for people to maintain their balance (for example, on glazed tiles or a metal roof that is wet from morning dew or light rain)

• near an unprotected open edge or internal void area (for example, removed roof sheeting).

Possible control measures to prevent similar incidents

The WHS Regulation requires specific fall risk control measures to be implemented, where it is reasonably practicable to do so. For example:

• if the work is construction work, then Chapter 6 of the WHS Regulation applies

• if the work meets the definition for high risk construction work (e.g. if the work is over two metres and it is a complete roof replacement of a large shed) then a safe work method statement must be prepared as provided for in the Work Health and Safety Regulation 2011. Further regulations would also then apply (for e.g. Part 6.3 Sub-division 2 “Falls” which provides prescriptive control measures).

Effective controls for the risk of falling from a height are often made up of a combination of controls. Some common control measures can include but are not limited to the following examples:

• Constructing a roof with the roof structure on the ground and then lifting it into place – this can eliminate many falls from heights hazards but is only suitable for the construction of some roofs on new structures where the roof can be lifted into place. In addition, lifting the roof into place will create other hazards that need to be addressed.

• Using an elevating work platform (EWP) to do work on a roof so workers can remain within the EWP and avoid standing on the roof. This is primarily an example of substituting the hazard for a lesser hazard. However, an EWP design may also be considered an engineering control measure and the EWP must be assessed to determine whether it is the most suitable one for the task/s.

  • The safe operation of EWPs also relies on safe work procedures (i.e. administrative controls), which includes ensuring operators hold the relevant high risk work licence (where required) to operate the particular EWP.

• Ensuring safety mesh, complying with AS/NZS 4389:2015, has been installed under the roofing and skylights and perimeter edge protection (complying with the Work Health and Safety Regulation 2011). Both safety mesh and edge protection are primarily engineering control measures that address the risk of falling through the roof or off the roof edge. However, safe systems of work need to be implemented for the workers installing the safety mesh and edge protection.

• Travel restraint systems intended to prevent a fall from a roof edge by physically restricting how close a worker can get to a roof edge. These systems are generally unsuitable where a fall through a roof can occur (i.e. because the roof is fragile or there is no safety mesh under the roof sheeting). They also largely rely on worker training and the worker following a safe system of work. A travel restraint system is a combination of an engineering control (system design), administrative control and personal protective equipment (i.e. the tethering lines and harness).

• Fall arrest systems for work on roofs are the least preferred risk control measure because they do not prevent a fall occurring but arrest the fall once it has occurred. The worker can still be injured, even if the fall arrest system is set up correctly and the worker's fall is arrested before the worker hits the ground or another obstruction. After the fall, the worker must be rescued both promptly and safely. Fall arrest systems are primarily a form of personal protective equipment but also rely on engineering controls (i.e. anchorage point strength, harness and lanyard design) and administrative controls (e.g. making sure the lanyard is connected and not too long).

In addition to the hierarchy of controls, the manufacturer’s instructions, should be followed, for the safe operation and use of plant, machinery and/or systems engaged by the PCBU.