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Cleaning a Building after Ashfall


Safety Considerations

Roof clean-up

Working on roofs is highly hazardous, particularly when they are covered in ashfall which makes surfaces slippery. Roof clean-up must be carefully planned and only done if you can do so safely. Many injuries and some fatalities have occurred while clearing ash from roofs, either due to falls or roof collapse. You should do your own risk assessment to see if it is safe to clear ash from your roof.

Suggestions to make working conditions safer:
  • Make sure there is a safe access point to the roof. Access ladders should be secured against movement and extend one metre (3.3 feet) above the stepping-off point.
  • Avoid electrical hazards such as power lines.
  • Be aware that roofs may have reduced capacity due to ash loading.
  • People working on a steel-clad roof should always step along the lines of nails/screws (if visible) and avoid working too closely together.
  • Be aware that ash-covered surfaces are slippery.
  • Place crawl boards or ladders on the roof for more secure footing.
  • Do not use a harness unless you have been trained in their safe use.
  • Do not work on steep roof sections.
  • Avoid any weak sections of the roof such as skylights or Perspex panels.
  • Isolate the area below the roof cleaning work to protect people on the ground from falling debris.
  • A broom is usually the best method for cleaning a roof. Sweep the ash off the roof onto the ground.
  • Lightly dampening the surface of the ash can reduce ash lifting into the air. However, too much water may cause the ash to become cemented and much more difficult to remove.
  • When piling ash on the ground, don't block building entry and exit points.

Physical demands of clean-up

Ash clean-up is physically demanding and time-consuming. Ash is typically much heavier than people expect, and strain injuries are common.
  • Avoid overfilling bags as they will be too heavy to lift safely.
  • Use wheelbarrows to move loads of ash.

For managers of clean-up teams

Clean-up managers may have legal duties under local health and safety regulations.
  • Check local health and safety regulations for any legal duties.
  • Ensure that workers use safe working methods (see above section).
  • Ensure that workers are provided with appropriate personal protective equipment (PPE).
  • Monitor worker fatigue and overheating while wearing heavy PPE.
  • Ensure workers have access to an outer room to remove ashy clothing, access to showering facilities and an eyewash station.
  • For more detailed information on safe working practices at height and on roofs, see the following on the Resources page:
  • For more detailed information on respiratory protective equipment for workers, see the following on the Resources page: