Preventing electric shocks when working in ceiling spaces

Electric shock hazards in ceiling spaces

Electric shock and electrocution are serious workplace health and safety risks. This guidance is for people who work in ceiling spaces, including:

• employers (including labour hire providers and host employers)
• employees
• contractors
• self-employed people

In most buildings, especially houses, much of the electrical wiring is run, or partly run, through the ceiling space. This includes electrical wiring for:

• lights
• socket outlets
• air conditioning
• other electrical equipment.

When people enter ceiling spaces to conduct installation, maintenance or repair work, there is an increased risk of electric shock and electrocution. Many people have been electrocuted inside ceiling spaces.

Causes of electric shock

The following hazards can cause electric shock or electrocution.

Worn electrical wiring insulation

Electrical wiring insulation can become brittle when it has:

• deteriorated
• been exposed to excessive heat

Brittle insulation can break into pieces when disturbed. This can expose the live conductors.

Vermin

Vermin can damage electrical wiring by chewing insulation. This can expose the live conductors.

Damage to the earth conductor or bonding

Hazards can develop from:

• damage to the main earth conductor or earth electrode
• main neutral faults

This may cause current to flow in the earth conductors, or metallic parts such as metal pipes, exposing someone to a risk of electric shock or electrocution.

Previous electrical work

Hazards can develop from:

• Illegal or sub-standard electrical work on the electrical installation.
• Older properties where lower standards applied to previous electrical work. For example, lights that did not have to be earthed.
• Other electrical work completed in the ceiling. For example, installing air conditioning or television cables.

Energy sources

Alternative sources of electricity, like solar panels and solar battery storage, may also be a hazard.

Controlling the risk of electric shock

An employer (including a labour hire provider and host employer) or self-employed person must eliminate the risk of electric shock or electrocution. This must be done so far as is reasonably practicable.

If risks cannot be eliminated, they must be reduced so far as is reasonably practicable.

The ways of controlling risks can be ranked from the highest level of protection and reliability to the lowest. This ranking is known as the hierarchy of control. Always start at the most effective control – Level 1, eliminate the hazard – and work down the hierarchy.

Safe elements of electrical isolation

It's important to isolate and test before any work begins. Follow these steps.

Residual current devices

While RCDs are designed to minimise the risks of electric shock, they should not be the only control used. This is because they:

• do not eliminate electric shock risks – they only reduce the risk of the shock being fatal
• may not protect all wiring in the ceiling space
• will only function in specific electric shock situations

Safe work method statements

Working in a ceiling space may be considered construction work.

Any construction work may also be considered high-risk construction work (HRCW). Examples of HRCW include when:

• it occurs on, or near, an energised electrical installation
• there is a risk of someone falling more than two metres

Employers, labour hire providers and self-employed people must prepare a safe work method statement (SWMS) for any HRCW before the work starts. They must also follow it during the work.

The SWMS must describe:

• the hazards and risks, including risk of electric shock
• what measures will be used to control the various risks
• how the controls will be applied

The SWMS should also outline a process for checking that the isolation was successful before any work begins.

Working in a ceiling space may include other HRCW that must also be addressed in the SWMS. See 'Related information' below to learn more about SWMS.

Controlling other risks

Working in a ceiling space may involve other risks that must also be controlled, so far as is reasonably practicable. These include:

• falls from height
• excessive heat
• dust
• biological hazards (vermin, insects, moulds)