Composite panels, also known as sandwich panels, are a popular construction material consisting of an insulation core sandwiched between two metal or plastic facings.

They are used extensively for external walls, internal structures and roof construction within a variety of industries, including cold storage, warehousing, food, hotels and other environments which adhere to stringent hygiene standards. Composite panels are a more favourable choice because of the following characteristics:

• Thermal insulation properties that curb heat and cold transmission
• Ability to muffle sound
• Light weight
• Easy construction
• Non-porous exterior that enables quick washing
• Lower cost compared to other materials

These factors can reduce initial construction costs and other ongoing expenses such as energy bills. While the benefits are clear, there also are serious risks involved with using composite panels. Depending on the core, panels can actually create a substantial fire hazard. As a business owner, you need to identify the risks of using composite panels and learn how to safely capitalise on this efficient resource.

Fire Risks

The combustibility of composite panels depends on the material their core is made from. The main combustible cores are made from one of the following:

• Expanded polystyrene
• Fire retardant expandable polystyrene
• Polyurethane
• Polyisocyanurate (standard)
• Polyisocyanurate (approved) – Provides some fire resistance

On the other hand, non-combustible cores consist of one of the following materials:

• Foamed glass
• Glass fibre
• Mineral wool – Mineral wool panels are insurers’ preferred option because these panels can contain the spread of fire. Unfortunately, they are not recommended for cold storage facilities, they cost more and are significantly heavier than other types of panels.

Most new construction projects will use panels with non-combustible cores, while older buildings containing panelling with combustible cores are exposed to severe fire risks, including:

• The potential of rapidly spreading fire
• Difficulty of fighting fire due to the chemical and concealed nature of the combustible core
• Liquid fire produced from melting cores
• Creation of dense, corrosive and toxic smoke
• Material breakdown which can expose panels’ cores and exacerbate the spread of fire

When a panel core catches fire, its chemical nature makes it difficult to extinguish and contain—think of it as molten fire that bursts forth from the walls. This can make it very dangerous for Fire and Rescue Service workers, and they may be limited to using only defensive fire-fighting tactics to prevent the spread of fire. In fact, except when human lives are at stake, the Fire and Rescue Service is reluctant to enter buildings in which combustible panels are on fire due to their high combustibility.

These risks are even greater in food factories, where composite panels are everywhere. Many factories rely on composite panels to cheaply establish diverse environmental conditions in different rooms within the same building.

Although combustible composite panels can be less expensive, owners may end up paying more in insurance premiums due to the panels’ increased risk. Some insurers do not insure premises with combustible panels. Others might, as long as the owners have an advanced fire prevention programme in place to reduce the risk of total loss.

Other Safety Risks

Even if composite panels are non-combustible, they still can cause fall injuries when they are used for roof and false ceiling construction in commercial buildings.

Because workers routinely need access to the ceiling for maintenance, some composite panels allow limited ‘walk-on’ access, which is determined by the manufacturer. However, this access is sometimes described using only vague terms such as ‘one man and one toolbox per panel for occasional access’. Unspecified phrases like ‘occasional access’ leave room for different interpretations and subsequent injuries. Always request the accurate load-bearing capacity of composite panels from the manufacturer and provide training for your employees so they know how to safety work on and around composite panels.

Reducing Your Risk

Although using composite panels in building construction can be risky, with adequate planning and a robust risk management programme you can capitalise on the material’s numerous benefits. Consider the following tips to help reduce your risk:

• Identify every panel core installed in the building
• Classify the fire rating of every installed panel
• Check for damage to the panels which increases fire risk
• Replace all combustible panels with non-combustible panels
• Construct two-hour firewalls, which retard the spread of fire, to compartmentalise fire risk
• Install a sprinkler system throughout the premises
• Purchase heat and smoke detectors that can be monitored off-site
• Appoint a manager to be responsible for creating a fire prevention programme and regularly conducting fire risk assessments
• Avoid placing flammable materials near, or running electrical cables through, panels