Confined space work on residential construction sites in Australia

What it is

A confined space sounds like a tunnel or a tank but in residential construction it is more often a rainwater tank, a sewer pit, a stormwater inspection chamber, an underfloor crawl space, a basement plant room, a fuel tank or a roof void. Under the model WHS Regulations a confined space is an enclosed or partially enclosed space that is not designed for continuous human occupancy, that is or is likely to be at atmospheric pressure and that has a restricted means of entry or exit. It also has to be capable of presenting a risk to health and safety from an oxygen problem, a contaminant, engulfment or fire and explosion. A space that fails the test in the regulation is not a confined space, even if it feels tight.

When residential work triggers the rules

Residential builders trigger the confined space rules when a worker needs to enter a space that meets that definition to do their work. Examples on a typical block include cleaning out a poly water tank before commissioning, installing a sewer pump in a pit, repairing a stormwater pit, working inside a roof space with poor ventilation in summer or accessing a subfloor on stumps. A roof void is the most common space residential builders forget about, particularly during retrofit insulation, antenna installation or air conditioner duct work in older Federation and post war homes.

What is not a confined space

A trench is not a confined space under the WHS Regulations even though excavation rules apply. An open balcony or a partially open verandah is not a confined space. A bathroom under construction is not a confined space. The test is the four part definition in the regulation, not whether the room feels small.

AS 2865 and the model Code of Practice

AS 2865 Confined spaces is the standard that sits behind the model Code of Practice for confined spaces published by Safe Work Australia. The code gives practical guidance on how to identify, assess and control the risks. Both documents work together. The PCBU uses the code to set up the system of work and uses AS 2865 to size the controls, train workers and write the entry procedure.

The permit to work system

Entry to a confined space must use a written entry permit. A competent person prepares the permit. The permit records the space being entered, the work to be done, the hazards identified, the controls in place, the atmospheric test results before entry, the workers entering, the standby person outside and the rescue arrangements. The permit is signed before entry, displayed at the entry point and signed off when everyone has exited. It is a record, not just a form.

Atmospheric testing

The permit cannot be signed until the atmosphere has been tested. A four gas meter checks oxygen, lower explosive limit, carbon monoxide and hydrogen sulphide as a minimum. Oxygen between 19.5 and 23.5 per cent, LEL below 5 per cent and toxic gases below the workplace exposure standards. If the space cannot be made safe by ventilation, respiratory protection moves up the hierarchy and rescue planning has to assume an unbreathable atmosphere.

Training and competency

Workers entering a confined space, standby persons and the issuer of the permit all need confined space training. The nationally recognised units of competency are RIIWHS202 enter and work in confined spaces and RIIWHS210 issue permits for confined space entry. Standby persons need rescue training that matches the rescue plan for the actual space they are watching, not generic first aid.

Rescue planning

The PCBU must have a rescue plan in place before entry. The plan covers self rescue, non entry rescue using a tripod and winch with a full body harness and entry rescue as the last option. Calling triple zero is part of the plan, not the whole plan. Fire and rescue response times in outer suburbs and rural residential areas can exceed the survivable time for an oxygen deficient atmosphere, which is why the standby and the equipment on the ground matter so much.

Common residential rescue gaps

The most common rescue gaps on residential confined space work are no standby person, a standby person who is also doing other tasks, a tripod set up but no rescue practice, no atmospheric monitor during the work and no plan for an unconscious worker in a roof void where a winch cannot reach. Each of those gaps shows up regularly in regulator incident notifications.

Records to keep

For each confined space entry on a residential build the builder should keep the risk assessment, the written entry permit, the atmospheric test record, the training records for workers involved, the rescue plan and any sign in or sign out log. SafeWork NSW, WorkSafe Victoria and WorkSafe Queensland all publish residential builder facing guidance that aligns with the model code.