Why it matters

The WSH Council counted 20 deaths from falls during roof work between 2007 and 2011. Falls through fragile surfaces caused about half of the fatal roof falls from 2009 to 2011.

Many of these were short jobs. Someone checked a gutter, fixed an air-conditioner or ran a cable. The roof looked solid. A sheet broke, and the worker fell through to the floor below.

How people fall from roofs

Before any roof job, look at the roof type, the slope, the height, the material, and how long the work will take. Then plan for these four ways to fall.

  • Over an open edge. Often at the point where the worker steps on or off the roof.
  • Through a fragile surface. Skylights, plastic sheets and corroded or old cement sheets.
  • Through an opening. A hatch, a gap left by a removed sheet, or an unfinished canopy.
  • After a slip. Wet or smooth surfaces, above all on pitched tile roofs.

Spotting a fragile roof

A fragile surface is one that may fail under any load you could reasonably expect, such as a person's weight. Skylights, glass, fibreglass, polycarbonate and acrylic sheets are likely to be fragile. So are old ceramic tiles and corrugated cement sheets. Sound sheets also turn fragile as they age, rust or crack.

Treat the whole roof as fragile until a competent person confirms it is not. Check from below or from a safe spot without stepping on it. Ask the owner what the roof is made of, how old it is, and where past repairs and patches are. Old cement sheets may contain asbestos. That work needs a contractor competent in asbestos removal.

The bolt line is not safe

Do not assume a sheet will hold you along the line of bolts above the purlins. The purlin edge can tear the sheet. Old repairs may have bolts with nothing underneath. A stumble adds enough load to break through.

Order of controls

The WSH Council sets out this order for fragile roofs. Combine steps where one alone is not enough.

  • Work from underneath. Use a suitable platform below the roof.
  • Work from a MEWP basket. The worker reaches the roof without standing on it.
  • Spread the load and guard the edge. Fit perimeter edge protection. Work from staging, crawl boards or platforms that span the supports. Unless all work is on guarded platforms, add harnesses or safety nets under the roof.
  • Harness last. It needs a proper anchor, a clipped-on worker the whole time, and close supervision.

Getting on and off the roof

Put the access in place before work starts, at the spot where the work begins. A scaffold or tower with guard-rails is better than a ladder. For new roofs or big repairs, plan an access tower or a hoist.

Keep the gap between a scaffold and the roof edge to 300 mm or less. A ladder must be tied and reach at least 1 metre above the landing for a handhold. Never climb from the top of an A-frame ladder onto a roof.

Climbing out of a MEWP onto a roof is a last resort. The maker must approve it, the worker stays tied off the whole time, and a written method covers the transfer. Control who goes up. A permit or locked access stops casual visits.

Edges, openings and crawl boards

Where there is no solid parapet, fit guard-rails on the inside of the roof edge. The top rail must be at least 1 metre high. No gap between rails, or between the roof and the lowest rail, may exceed 600 mm.

Cover openings in the roof. A cover must carry at least twice the expected load, bear on all four edges, be fixed down, and carry the word HOLE or COVER.

On fragile or pitched roofs, run crawl boards from ridge to eaves and fix them with ridge hooks. String a lifeline beside each board. Roof brackets must fit the pitch and give a level platform.

Travel restraint keeps a worker away from an edge. It is not for fragile roofs, because the danger is underfoot. There, use fall arrest with enough clearance, or nets fitted close under the work.

Weather, materials and people

Stop roof work in bad weather. That includes straight after rain, when the surface is slick, and when lightning is about.

Plan deliveries so the right materials arrive at the right spot. That cuts walking on the roof. Before stacking anything up there, check that the structure can carry it. Keep loose materials back from the edge.

Never let one person work alone on a fragile roof. A second person must be present to raise the alarm and start the rescue. New workers stay where the supervisor can see and talk to them.

What the rules require (Singapore)

Roof work falls under the WSH (Work at Heights) Regulations 2013. The WSH Council roof guidelines and the Code of Practice for Working Safely at Heights explain how to comply.

  • Roofs (reg 16). Where someone could fall off or through a roof more than 2 metres, the responsible person must provide protection against sliding or falling, such as crawl boards or roof brackets. They must also provide secure anchorage for a harness or restraint belt, and see that the worker uses both.
  • Avoid fragile surfaces (reg 17(1)). Nobody should cross, work on or work near a fragile surface where the job can reasonably be done another way.
  • Support the load (reg 17(2)). Where that cannot be avoided, provide platforms, covers, guard-rails or similar so any foreseeable load is carried.
  • Warning notices (reg 17(3)). Fix prominent notices at the approach to a fragile surface. If that is not practicable, tell the worker some other way.
  • Fall prevention plan and permit. A fall prevention plan applies at the workplaces listed in the regulations, and the permit-to-work rules cover hazardous work at height in factories.
Penalties

Breaking regulation 16 or 17 can bring a fine of up to $50,000, up to 2 years in jail, or both (reg 31).

Common mistakes

These show up again and again in roof falls.

  • Stepping on a skylight hidden under dust or paint.
  • Walking the bolt line because "that is where the purlin is".
  • A sheet lifted for replacement and the gap left open.
  • A ladder that stops short of the gutter, so there is nothing to hold at the top.
  • A harness clipped to a vent pipe or a gutter bracket.
  • One worker sent up alone for a "five-minute" aircon check.
It held me last time

Roof sheets weaken with age and sun. A sheet that took your weight last year may not take it today.

In other countries

  • Indonesia: Permenaker No. 9 of 2016 requires the employer to make sure no worker approaches, crosses, or works on or near a fragile surface (Article 14). Source: Permenaker 9/2016 (BPK database).

Use it on site: the roof work and fragile roofs checklist and the toolbox talk to brief your crew.

Sources

  1. Workplace Safety and Health (Work at Heights) Regulations 2013, Singapore Statutes Online (AGC).
  2. WSH Guidelines: Working Safely on Roofs (revised 2013), WSH Council.
  3. Code of Practice for Working Safely at Heights, WSH Council.
  4. Working Safely on Roofs, WSH Council.
  5. Permenaker No. 9 Tahun 2016 tentang K3 dalam Pekerjaan pada Ketinggian, Kemnaker (via BPK JDIH).

This is practical guidance, not legal advice. Laws and codes of practice change; always check the current official text and your site's own procedures.