5 . DEMOLITION METHODS
The sequence in which a building or other structure is demolished can be critical for the health and safety of workers and the general public .
The demolition sequence will depend on things like the type of construction , location , and demolition method ( s ) selected . Buildings and structures should generally be demolished in reverse order to their construction , that is , by ‘ sequential demolition ’. In particular :
• sequential demolition should be carried out in reasonably even stages , commencing from the roof or top of the building or structure being demolished
• multi-storey buildings or structures should be demolished storey by storey
• masonry and brickwork should be taken down in reasonably even courses .
There is a range of demolition methods that may be used , either separately or in combination . Control measures should be selected on the basis of the demolition method ( s ) used . However , no matter what method is used , the building or structure to be demolished and all its components should be maintained in a safe and stable condition so as to prevent the unexpected collapse of part or all the structure . Temporary braces , propping , shoring , or guys may need to be added for stability .
Further information on demolition methods can be found in AS 2601 : The demolition of structures .
5.1 Manual demolition
Manual demolition includes any technique where hand tools such as jackhammers , sledge hammers and picks are used .
Manual demolition has many of the hazards that are present in other major demolition activities including unexpected collapse , falls , falling objects , manual handling and exposure to noise , dust and hazardous chemicals .
To manage the risk of unplanned collapses , the condition of roofs , walls and floors of the building should be assessed by a competent person before commencing demolition work .
Where concrete members are being demolished manually , the reinforcement shall not be cut while breaking of the concrete is in progress .
Where pre and post-tension demolition work is undertaken competent person advice should be sought as to demolition sequence . More information on the demolition of pre and posttensioned concrete is at Section 6.1 of this Code .
Areas where debris will fall should be barricaded off and signs erected to prevent persons from entering before demolition starts .
MANUAL DEMOLITION OF ROOFS Controlling the risk of falls of persons or objects is an important consideration for roof work .
Where it is not reasonably practicable to demolish a roof using mechanical means or to remove the roofing from work platforms below the roof , then careful consideration should be given to the most suitable method of protection for workers engaged in the removal of the roofing . For example , roof trusses should be removed using safe temporary work platforms . It is important to ensure that the removal of trusses does not cause wall instability .
CODE OF PRACTICE | DEMOLITION WORK 25