In May 2018, two workers fell to the ground when the second storey floor of a residential building under construction collapsed after materials were placed on it by a crane. One worker sustained a broken ankle. Investigations are continuing.
Preventing a similar incident
Multi-storey building construction has working at height risks, including the risk of falling from or through voids in the structure or floor. These are compounded when additional risks are introduced such as overloading the structure with materials or plant needed for the construction work.
A floor or structure collapsing can have devastating outcomes. Principal contractors, PCBUs, contractors and workers must consider the consequences of introducing additional loads to a structure and ensure that it is capable of supporting these loads. Stacks of flooring, framing and other construction materials are regularly lifted onto the second storey of a building as it is being constructed. These stacked materials create point loadings which the floor, joists or structure may not be designed to bear. Materials should be stored only where and when the structure is able to bear the load, in a designated landing area that has been deemed capable of supporting the load by a competent person.
To minimise the risk of collapse:
construction drawings should clearly identify the maximum point loadings for the structure and should show designated landing areas
loads craned onto the structure should not exceed the maximum weight specified
loads should only be placed in designated landing areas.
Suitable controls must also be in place to prevent the risk of a fall by a worker while on a multi-storey building, including:
void protection covers
scaffolding and hoarding.
Part 4.4.1 of the Formwork Code of Practice 2016 provides additional information which may correlate to the point loading of structures.
Since 2012, there has been an average of 28 workers’ compensation claims accepted for injuries received by workers falling through a roof or floor. Of these claims, 56 per cent involved a serious injury and almost 70 per cent were in the construction industry.
In the same period, there have been 139 incidents involving workers or others falling through a roof or floor, of which five were fatal. We issued 624 compliance notices for issues relating to falling through a roof or failure to manage risks associated with working at height.
Prosecutions and compliance
In December 2017 a company was fined $65,000 after an experienced carpenter working at a construction site fell through a stairwell void in the first floor. The worker sustained a fractured skull, cheek and vertebrae, and a brain bleed. The worker and the site supervisor had been carrying a prefabricated wooden frame work without any controls in place to prevent someone falling through the void. The supervisor was walking forward and the worker backwards, when he fell through the unprotected void.
In June 2016, a company was fined $20,000 after two workers were injured when formwork collapsed while a suspended concrete floor was being poured. The defendant allowed the pour to progress without engineering sign-off and the collapse occurred as a result of there not being adequate support for the span of the formwork.