Wall collapse - 3 September
While being demolished, a seven-metre brick wall collapsed onto a neighbouring property in the Sydney suburb of Balgowlah. Although no-one was injured, occupants were evacuated and Public Works said the property would need to be demolished because of the damage and unstable structure
- SafeWork NSW inspectors responded to the incident.
- SafeWork NSW commenced an investigation to determine the cause and circumstances of the incident.
Consider ‘reasonably practicable’ control measures to manage the risks associated with unplanned structural collapse during demolition and excavation work. Before starting demolition work:
- Collect all structural documentation for the building, such as ‘as-built’ structural drawings, geotechnical reports and designer safety reports.
- Get a competent person to give you an engineering report, if structural or geotechnical information isn’t available, if the structure has been damaged or weakened (by fire or deterioration), or if the demolition method will impose substantial stress on the building.
- Get a competent person to check the building for asbestos, make sure it’s removed and get a clearance certificate before starting to demolish.
- Consult with all relevant competent persons during the planning of the demolition works, considering the structural documentation and/or engineering investigation reports.
When planning the works, consider the:
- effect of the proposed demolition methods and sequence on the stability and integrity of the structure being demolished, and any adjacent or adjoining buildings, at all stages of the demolition
- maximum permissible wind speed for partially demolished structures
- plant to be used for the work, including the size, type, position and reach
- ground conditions and how that may affect the use of plant or other demolition methods
- safe access and safe working areas.
- Tell all relevant people when ‘hold-points’ are required during the demolition sequence, to allow for the inspection and/or testing by competent persons.
- Make sure workers are competent and have received training and instructions on the demolition methods and sequencing.
When undertaking demolition work:
- Make sure the work is supervised by a competent person and done in accordance with the planned methods and sequence.
- Use braces, propping or shoring, to make sure the building and any nearby structures are safe and structurally stable at all times.
- Use exclusions zones to protect workers from falling objects, unplanned structural collapse and moving plant – even when work has stopped for the day, or if the risk of a structural collapse exists.
- Implement fall protection devices if work is done at heights.
- Don’t work from the top of a wall that is being demolished.
- Make sure adequate controls are in place to minimise exposure to silica dust.
- Wear safety glasses, ear muffs, dust masks, gloves and long-sleeved clothing.
When removing entire wall sections using manual demolition methods that incorporate hand tools, such as jackhammers, sledge hammers, and picks, avoid weakening the wall by:
- starting demolition at the top course of bricks using a hammer and chisel
- removing an entire row before starting the next.
- Demolition work code of practice
- Excavation work code of practice
- Wall safety during excavation work guidance material
- AS 2601-2001: The demolition of structures