Safe erection of roof trusses checklist

Guidance for employers, including principal contractors and contractors. It provides information and a checklist to help you meet your occupational health and safety (OHS) duties to keep employees safe when erecting timber or lightweight steel roof trusses in domestic housing construction.

Background

The erection of roof trusses is a high-risk activity due to fall hazards associated with working at heights and the potential of structural collapse during the erection process.

This checklist should ensure all safety basics related to the erection of roof trusses have been considered and applied.

This checklist has been developed in consultation with Foundations for Safety members (FFSV).

Employer duties relating to high risk construction work

The erection of roof trusses may place employees at risk of falling from a height that is greater than 2 m. Placing trusses onto housing frames using powered mobile plant, such as a vehicle loading crane, may also be required. In these situations, roof truss erection meets the definition of high risk construction work (HRCW) within Part 5.1 of the Occupational Health and Safety Regulations 2017 (OHS Regulations).

When employees are undertaking HRCW, employers must develop a safe work method statement (SWMS) in accordance with Part 5.1 of the OHS Regulations. Employers should ensure that the SWMS is:

  • prepared in consultation with the employees who will do the HRCW and HSR's
  • implemented in addition to their general duty to provide a safe workplace
  • reviewed when the HRCW changes or there is any sign that the risk controls measures are not controlling risks

Employers must also keep a copy of the SWMS for the duration of the HRCW.

Hierarchy of control

The hierarchy of control is a system for controlling risks in the workplace. The hierarchy of control is a step-by-step approach to eliminating or reducing risks and it ranks risk controls from the highest level of protection and reliability through to the lowest and least reliable protection.

Employers must know the controls covered in Part 3.3 of the OHS Regulations when developing the SWMS and when planning the measures to control any risk of falling (Regulation 44 Control of risk).

Hierarchy of control measures for the prevention of falls

The following measures show the structure of the hierarchy of control, from highest to lowest level of protection.

Checklist

The following checklist covers:

  • truss design
  • preparing the site for truss delivery
  • use of a crane
  • development of site specific erection methods
  • formation and preparation of erection crew
  • Factors that may impact handling and the number of persons required

Work through this checklist to help reduce and manage the risks associated with the erection of roof trusses.

Truss design

Preparing the site for truss delivery

Use of a crane

Development of site specific erection methods

Safe work method statement (SWMS)

A SWMS ensures that the HRCW is documented — it should include specific factors such as:

  • available site access and storage
  • truss size and design
  • type of fall protection to be used for persons working near the external perimeter of the building
  • fall protection to any stair voids
  • type and suitability of any internal platforms to be used
  • type and suitability of any ladders to be used
  • the way in which trusses are to be manoeuvred at ground level and at top plate level
  • additional equipment needed to install trusses
  • identifying the possibility of structural collapse
  • the manner in which truss bracing and spacers are to be installed to minimise fall risks this information — may be found in Truss Installation guides and Australian Std AS4440 (Truss installation)
  • weather conditions that might impact work
  • safe use of power tools including electrical safety

Note: Many employers involved in truss erection will have a basic or generic truss erection SWMS that forms the basis of their work procedure for most sites. However, it is likely that some of the assumptions will vary, including site conditions and truss designs. Employers must ensure that a generic SWMS is reviewed and adjusted as necessary for each specific site. For more information on SWMS, refer to Safe Work Method Statements (SWMS).

Safe Work Method Statements (SWMS)

Truss erection procedure
Figure 1: Truss erection procedure including hanging bracket scaffold as external fall protection, internal working platform with trusses spread as internal fall protection. Note: Internal worker remains behind brace truss and over platform.
  • Trusses to be laid or spread out (preferably from underneath) and overlapped to form a temporary platform or internal fall protection above walls.
  • Worker standing trusses remains central on planks or wall with trusses laid out either side to prevent falling through.
  • Once first truss is erected and braced worker on top remains behind braced trusses standing one truss at a time in a sequential manner.
  • Workers on outside remain on external scaffold to help with erection and bracing of trusses.
  • Process needs to documented in Safe Work Method Statement (SWMS).
Truss erection procedure with workers inside frame
Figure 2: Truss erection procedure including internal trestles and planks so top plates acts as external fall protection, internal worker over internal wall with trusses spread as internal fall protection.

Note: Internal worker remains behind brace truss and over platform. Workers must remain inside frame at all times.

  • Trusses to be laid or spread out (preferably from underneath) and overlapped to form a temporary platform or internal fall protection above walls.
  • Worker standing trusses remains central on planks or wall with trusses laid out either side to prevent falling through.
  • Once first truss is erected and braced worker on top remains behind braced trusses standing one truss at a time in a sequential manner.
  • Workers on trestles/planks remain inside frame with top plate acting as handrail to help with erection and bracing of trusses.
  • Process needs to documented in Safe Work Method Statement (SWMS).
Worker positioning on internal top plate. Worker remains behind braced truss with feet over top plate or work platform.
Figure 3: Worker positioning on internal top plate. Worker remains behind braced truss with feet over top plate or work platform.
  • Trusses to be laid or spread out (preferably from underneath) and overlapped to form a temporary platform or internal fall protection above walls.
  • Worker standing trusses remains central on planks or wall with trusses laid out either side to prevent falling through.
  • Once first truss is erected and braced worker on top remains behind braced trusses standing one truss at a time in a sequential manner.
  • Process needs to documented in Safe Work Method Statement (SWMS).

Formation and preparation of erection crew

Factors that may impact handling and the number of persons required

An assessment of the following factors should be done to determine how roof trusses are to be handled and the number of persons needed at each stage of the process.

Factors to consider include:

  • size of trusses (including span height and weight)
  • restrictions on handling imposed by site or house design
  • cranage availability

More information