Working at Heights on Roofs

What the law actually asks

There's a persistent belief that fall protection kicks in at a particular height and below it you're fine. That's not how the duty works. You have to manage the risk of a fall wherever a fall could injure someone — and the regulations set specific trigger heights on top of that for particular controls and for when work counts as high-risk construction work. Those heights differ by jurisdiction and get revised, so get the current numbers from your state regulator rather than from a number someone quoted you on site.

What's consistent everywhere is the order you're expected to work in. Reaching for a harness first, because it's what's in the ute, is the single most common failure — and it's the one an inspector will pick up immediately.

The order to work through

Start at the top and only move down when the option above genuinely isn't reasonably practicable. Write down why you moved down — that's the record that shows you assessed it.

1. Do the work from the ground. Prefabricate on the ground, use extension tools, use a camera or drone for inspection, install gutter guard from a platform. The fall risk you eliminate is the only one you never have to manage.
2. Work from a solid construction. A properly designed and installed platform, scaffold or elevating work platform with guardrails. Passive protection that works whether or not anyone remembers to clip on.
3. Use a passive fall prevention device. Perimeter edge protection, guardrails, scaffolding, and safety mesh under the roof sheeting. Nothing to put on, nothing to adjust, nothing to forget.
4. Use a work positioning or travel restraint system. A harness and line set short enough that the worker physically cannot reach the edge or the fragile area. The fall doesn't get arrested — it doesn't happen.
5. Use a fall arrest system. Harness, anchor, energy absorber and line, sized to stop a fall before impact. This catches someone who has already fallen, which is why it sits this far down.
6. Use a ladder or administrative controls. Last resort, for short-duration, low-risk access only. Not a way of working on a roof.

Roof safety mesh, and fragile roofs

Edge protection stops someone falling off a roof. Safety mesh stops them falling through it — a different hazard with a different control, and the one that kills people on re-roofing and maintenance work.

Mesh is a welded wire layer installed over the purlins before the roof cladding goes on, fixed to the structure so it can catch a person and the tools that come down with them. There's an Australian and New Zealand standard covering safety mesh, with requirements for wire diameter, tensile strength and spacing — specify to the standard and get the current version rather than working from a supplier's old data sheet. Mesh gets covered by the cladding as soon as practicable, and it isn't a substitute for edge protection.

The bigger day-to-day issue is existing roofs. Treat a roof as fragile unless a competent person has assessed it and said otherwise. Likely-fragile materials include:

• Asbestos cement sheeting — fragile and a respiratory hazard both. Stop and assess before anyone goes near it.
• Fibre cement sheeting of any age.
• Corroded metal sheeting, and sound sheeting with corroded fasteners.
• Skylights, roof lights and polycarbonate — often painted over, often invisible from above in glare.
• Glass, including wired glass.
• Rotted timber, chipboard, slates and tiles.
• Liner panels on built-up sheeted roofs.

Never walk on a fragile roof to inspect whether it's fragile. Assess it from a platform, from below, or from an elevating work platform.

When a harness system is the answer

If you've genuinely worked down to fall arrest, the system has to be complete and it has to be sized. Four parts, and all four matter:

• The anchor. Fixed to a structural element — a truss, a purlin, a rafter — never to cladding, battens or sheeting. Rated for fall arrest, installed to the manufacturer's instructions, and inspected.
• The harness. Full body, correctly fitted, with the attachment point where the manufacturer specifies. A loose harness transfers the fall load to the wrong place.
• The connector. Lanyard or self-retracting lifeline with an energy absorber sized to the system, and locking connectors that can't roll open.
• The fall clearance. The distance below the working surface has to be greater than the free fall, plus absorber extension, plus harness stretch, plus the worker's height below the attachment, plus a safety margin. On a single-storey house there frequently isn't enough clearance, which means fall arrest is the wrong control and you need restraint or edge protection instead.

Australian and New Zealand standards cover industrial fall-arrest systems and their components, including inspection and the competence expected of users. Use them to specify equipment and to set your inspection regime. Equipment gets checked before every use, inspected periodically by a competent person, and taken permanently out of service after arresting a fall.

The rescue plan nobody has

A harness that catches someone leaves them suspended, and suspension is dangerous on its own. Being held motionless in a harness restricts blood return and a suspended worker can deteriorate quickly — far faster than an ambulance can reasonably be relied on to arrive.

So if you're using fall arrest, you need a rescue plan before work starts, and it can't be "call triple zero". A workable plan covers:

• Who raises the alarm and how, including when the person on the roof is working alone — which is itself a reason not to.
• How the person gets down, with the specific equipment named and on site. An elevating work platform already there beats an improvised rig every time.
• Suspension relief straps fitted to the harness so a suspended worker can take weight off their legs.
• Who's trained to do it, and when they last practised.
• Medical follow-up. Anyone who's been suspended goes to hospital, even if they say they're fine.
• Call 000 as well, always — the plan runs in parallel with emergency services, not instead of them.

Making it part of how you quote and run jobs

Height controls fail commercially before they fail technically. Scaffold costs money, an elevating work platform costs money, and a business that hasn't priced them will find a reason not to use them at eight in the morning with rain forecast.

• Quote the access method as a line item. Scaffold, edge protection or EWP hire, named and priced. If the client wants it cheaper, that's a conversation about scope, not about safety.
• Do the access assessment at quoting time, on site. Roof pitch, condition, fragile elements, anchor availability, ground conditions for a platform.
• Write it into the SWMS. Roof work almost always falls into high-risk construction work, and the SWMS is where the chosen control and the reason for it get recorded.
• Check the gear on a schedule. Harnesses, lanyards and anchors have inspection intervals and service lives.
• Never send one person onto a roof alone where fall arrest is the control. There's nobody to run the rescue plan.

Frequently asked questions