flammable cladding, construction, aluminium cladding

Managing Flammable Cladding Risk

Earlier this year, the IAG Risk Partners team partnered up with fellow IAG business Strata Unit Underwriters (SUU) to look at the fire risk of Aluminium Composite Panels (ACP).  There has been plenty of media coverage of the risk following the fires at Grenfell Tower in London and the Lacrosse building here in Australia. Read on to find out more about ACP and the risks associated with it, and how to manage it.

What is ACP?

ACP are flat panels consisting of two thin coil coated aluminium sheets bonded to a non-aluminium core creating an aluminium composite material. The standard ACP core is polyethylene (PE) or polyurethane (PU). Typically, these materials are considered combustible by the insurance industry. Today there are over 950 ACP products available on the market. ACP also come in a more fire-retardant product where the core contains a blend of low density polyethylene and 70% or 90% mineral wool to exhibit fire retardant properties. Australian Standard AS5113 (AS5113:2016 Fire propagation testing and classification of external walls of buildings) outlines testing procedure to determine and classify the panels’ combustible nature and tendency to limit the spread of fire via the external wall and between adjacent buildings. ACP construction techniques have experienced considerable development in the last 40 years. Previously considered products suitable only as architectural features, ACP gained widespread use in residential and commercial buildings including hospitals, schools and retail outlets due to it’s good insulation characteristics, versatility, quality and aesthetics.

ACP use

ACP first appeared as architectural features on buildings, but it is now common to see whole buildings covered. It is still mainly used for external architectural cladding, however applications of ACP are not limited to external cladding, it is also used as partitions, false ceilings, etc. ACP is also widely used within the signage industry as an alternative to heavier, more expensive substrates. ACP is a light-weight and weather resistant material with excellent thermal, acoustic and mechanical properties. ACPs cost, durability, efficiency, flexibility, low weight, easy forming and processing  enables innovative design with increased rigidity and durability. The aluminium sheets can be painted in any colour, metallic or non-metallic as well as patterns that imitate other materials, such as wood or marble.

ACP risk

The use of ACP has a significant bearing on the combustibility and spread of fire along or within a building. It can seriously compromise life safety if the installation deviates from the National Construction Code (NCC) requirements. ACP will elicit different fire characteristics, depending on:

  • the core material
  • the metal thickness
  • the coating
  • installation and sealant type
  • tasks undertaken on ACP and around the panels
  • maintenance
  • active and passive risk engineered solutions
  • adequacy of fire protection systems

Other factors such as the cavity design between the cladding and the exterior wall of the building (or its sheath of insulation) are also significant. The cavity spacing can act like a chimney flue and draw flames upwards by convection, elongating flames up the structure. For buildings with Type A or B construction, the NCC requires external cladding to have defined smoke growth and flame propagation rates dictating a non-combustible or fire resistive insulating core to be used to limit vertical fire spread. However, recently fire safety concerns have emerged around the non-compliant application of ACP for external wall cladding.

What can you do to understand and manage your ACP risk?

It is important to understand the type and fire rating of the ACP product installed so that you can make informed decisions about how you manage your exposure. Below are suggested steps you should take:

  • Confirm the brand and specification details of the ACP installed.
  • Understand NCC regulations and if the existing panel installation is compliant with Australian Standards.
  • Ensure the product has been installed correctly and in line with manufacturer’s recommended methods, correct fixings, correct sealants etc.
  • Gain a full understanding of the current maintenance and management practices being undertaken including adequacy of fire suppression installations.
  • Seek guidance from a professional Risk Engineer to assess the above and provide comment on compliance with current regulation, adequacy of current management practices and guidance on best practice for managing the exposure.
  • Provide recommendations for management options available to mitigate the risk to life and property damage.

Questions?

Should you need advice or support from the team at IAG Risk Partners to understand and manage your ACP exposure, please don’t hesitate to contact us.

Source: https://www.suu.com.au/wp-content/uploads/2019/02/ACP-compressed.pdf