During construction work, inadequately secured masonry walls (brick or block) can fail due to side loads on the walls, the rate of construction, inadequate foundations or adjacent excavations. Side loads may include wind, inadvertent impact with the walls or leaning materials against them. Such failures can result in serious injuries or fatalities.

Persons are exposed to risk when entering the potential fall zones of incomplete or inadequately secured masonry walls. Potential fall zones include adjoining properties or public areas where there is a risk of the wall falling beyond the construction site.

Persons Conducting a Business or Undertaking (PCBU’s) must manage the risks associated with masonry wall construction to ensure the health and safety of their workers and others.

The safety of masonry walls can be improved during construction work with good planning and preparation, risk management and (where required) temporary supports.

Temporary supports – e.g. braces – are often required until the wall is incorporated into the completed structure and/or the wall has gained sufficient strength to withstand the loads applied to it.

Whilst principal contractors and masonry contractors are primarily responsible for the masonry work on site all PCBUs have an obligation to ensure their workers are not placed at risk.

As part of the planning and preparation principal contractors and masonry contractors should:

• determine who is responsible for assessing the stability of masonry walls prior to tying in to the completed structure
• determine who is responsible for installing, inspecting and removing any temporary supports
• provide designs and materials for temporary supports, considering the particular walls’ characteristics (seek engineering advice if necessary)
• provide materials to identify no-go zones – e.g. fencing, tape or signage
• provide instruction for workers, including site induction and supervision.

If you’re a masonry contractor, you must also prepare a safe work method statement in consultation with workers and get it reviewed by the principal contractor before you start work. Ensure that you use any relevant information from the manufacturer, supplier and site management.

Figure 1 - Illustration of unsupported wall height above a brace

Note 1: The upright member above the diagonal is ignored, as it may not be rigid enough to provide support. If the brace was not in place, the maximum unsupported wall height from table 2 would apply from ground level.

Note 2: Unless the brace is structurally connected to wall near the top of the diagonal, usually a through connection with plate on the far side, it is only preventing the wall falling toward the brace and another brace may be required on the other side of the wall.

A risk assessment considers the severity of any injury or illness that could occur and the likelihood or chance that someone will suffer an illness or injury. The risks associated with masonry wall construction are typically high due to the severity of the injuries that could occur.

Under the WHS Regulations, a risk assessment is not mandatory for construction work except for specific situations. However in many circumstances a risk assessment will assist in determining the control measures that should be implemented.

It will help to:

• identify which workers are at risk of exposure
• determine what factors are causing that risk
• identify if and what kind of control measures should be implemented
• check the effectiveness of existing control measures.

A risk assessment is not necessary if the risk and how to control it is already known.

Having identified the hazards and assessed the risks, you must manage those risks by implementing control measures. Risk control measures may include:

• designing walls to provide additional stability during the construction phase, such as adding sequential core filling with reinforcing or wall stiffeners (see figures 2 and 3)
• building walls at the same time as cross walls (see figure 4) or returns, or nailing-off frame ties in veneer construction, so that they support each other
• installing temporary supports (see figure 5)
• establishing stop heights to allow mortar to gain adequate strength before further construction – e.g. at lintel height
• storing materials away from unsupported masonry walls – i.e. not leaning materials against walls
• preventing inadvertent impact on walls by plant such as wheelbarrows, cranes or pallet trolleys – e.g. using dedicated travel paths and storage areas
• monitoring weather conditions – e.g. wind (see table 1), extreme temperatures and heavy rain – and amending work practices to suit
• stopping work if the existing top course is affected by rain to the point where the mortar bond strength will be impaired
• preventing the collapse of excavation behind masonry retaining walls
• not backfilling behind masonry retaining walls until they are permanently supported or (for self-supporting walls) have reached their design strength
• installing no-go zones, identified by barricades or other physical identifiers, to keep people outside of potential collapse zones. (This is not an adequate control measure for walls that could fall outside the construction site). Prevent such walls from falling under all likely conditions
• communicate the adopted risk control measures to all relevant people on site via site-specific induction training. Also communicate any changes to the controls – e.g. via toolbox talks.

Figure 2: Sequential core filling with reinforcing

Figure 3: Wall stiffener – open-ended blocks used to build around stiffener

Figure 4: Cross walls

Figure 5: Examples of typical types of temporary supports (not to scale).

(A) Metal triangular brace

(B) Timber triangular brace

(C) Metal prop brace

Ensure that any no-go zone extends – at right angles to the wall on both sides – a least the distance equivalent to the total unsupported wall height plus 1.2 m.

If winds exceed ‘fresh winds’ (see table 1), establish a no-go zone – regardless of any wall supports already in place.

Consider individual no-go zones for each wall, isolating specific areas or isolating the entire site.

Do not let anyone within the no-go zones.

A no-go zone can be removed once the reason for it no longer exists, eg - wind no longer exceeds ‘fresh winds’.

Note: You may need no-go zones for issues other than masonry wall failures eg - for falling objects.

The control measures used, e.g. temporary supports, must be monitored and reviewed to make sure they remain effective. Walls and temporary supports should be inspected for damage and/or movement on a regular basis, typically at the start of each day and after adverse weather conditions. If repairs are required, maintain no-go zones until it is safe to approach.

When reviewing control measures, the SWMS must also be reviewed and revised where necessary.

If problems are found, go back through the risk management steps, review your information and make further decisions about control measures.

Temporary supports must be maintained until the wall is incorporated into the completed structure or alternative support is provided e.g. a cross wall.

• Call us on 13 10 50
• Dangers from masonry walls on construction or demolition sites safety alert
• Think Brick Australia – Manual 10: Construction guidelines forclay masonry
• National Construction Code 2016
• Australian Standards: 
  • AS 1170 - Structural design actions (series)
  • AS 3600 - Concrete structures
  • AS 3700 - Masonry structures
  • AS 4055 - Wind loads for housing
  • AS 4455 - Masonry units, pavers, flags and segmental retaining wall units – Part 1: Masonry units

Contributors to the 2009 edition of this guide included:

• Austral Bricks
• Australand
• CFMEU
• Concrete Masonry Association
• CSR
• Department of Justice – Workplace Standards Tasmania
• Fugen
• Housing Industry Association Ltd
• Masonry Contractors Association
• Master Builders Association NSW
• Mirvac Limited
• SafeWork South Australia
• Workplace Health and Safety Queensland, Department of Justice and Attorney-General
• WorkSafe Western Australia.

This guide was first published in 2009 by WorkCover NSW.

This revised edition, published September 2017, has been updated to reflect changes in NSW Work Health and Safety legislation (WHS legislation).