Fire separation: the importance of keeping fire contained

• Fire can spread rapidly depending on building design and fire load.
• Effective fire separation slows its spread, limiting smoke and heat damage to the property, contents, and stock.
• Regular monitoring and maintenance help ensure fire separation remains effective.

Fires can move quickly. In a residential property, it can take just 60 seconds for flames to take hold, and within three minutes, temperatures can exceed 800°C.¹ In commercial buildings, large open areas and interconnected spaces can make containment even more challenging.

That’s where fire separation comes in. Fire-resistant barriers such as walls, floors, and ceilings help slow or stop the spread. This can protect both occupants and property by limiting damage and giving people more time to evacuate.

However, effective fire separation isn’t just about the construction of a building; it requires ongoing monitoring and maintenance to remain effective.

What is fire separation?

If a fire starts in a building, slowing or stopping its spread is crucial. Fire separation is the use of fire-resistant materials and structures designed to contain flames, smoke, and heat within a specific area. This includes fire-rated walls, ceilings, doors, and flooring, which can act as passive fire barriers to limit the spread of fire.

Why is fire separation needed in a building?

Fire separation is essential for protecting lives and minimising property damage. It can help to contain a fire at its source, slowing its spread and reducing risk to occupants.

By creating barriers that limit fire movement, effective fire separation can mean more time for evacuation and can help prevent flames and smoke from reaching critical areas, such as plant rooms.

“For example, if a fire starts on one floor of an office building, fire-rated walls and floors can slow its spread to other levels. That extra time can make all the difference for the people evacuating and for the emergency crews responding,” said David Sullivan, Practice Lead, Property Risk Management, QBE Australia Pacific.

What type of buildings need fire separation?

Fire separation is required in a wide range of buildings, from residential to commercial and industrial.

In residential buildings, it is commonly used between adjoining properties, such as townhouses and apartment complexes, to prevent fire from spreading between the buildings.

In commercial and industrial buildings, fire separation is often used to protect specific areas, such as warehouses, plant rooms, or server rooms, where the fire risk and potential impact may be greater. It can also help limit the impact of fire in shared commercial spaces, such as shopping centers or office buildings with multiple tenants.

For specific requirements relating to fire separation in different building types, refer to the National Construction Code (NCC), available on the Australian Building Codes Board website.

When should fire separation be considered in a building?

Fire separation is a key consideration during the design and construction of a building. Many elements—such as fire-rated walls, ceilings, and doors—are built into the structure to help contain fire from the outset.

While some fire separation features, like fire doors, can be retrofitted, fully compartmentalising an existing building can be difficult. However, there are ways to improve fire separation, even in older structures.

“As an example, one of our customers needed to store flammable liquids within their building, so they constructed a dedicated cut-off room using fire resistant materials and sliding fire doors to protect openings. This provided fire separation between the storage of flammable liquids and adjacent production areas,” said Sullivan.

What are some of the ‘hidden’ risks in fire separation?

Some fire risks aren’t immediately obvious, but they can make a big difference in an emergency. For example, cables, pipes, and ductwork that pass-through walls and floors can leave hidden openings if they aren’t properly sealed. Fire-resistant walls can also be compromised if gaps are filled with combustible foam or if contractors fail to replace fire stopping after completing their work.

Other risks include shared structures like pedestrian bridges, tunnels, or conveyor belts, which can allow fire to travel between buildings. Even storage choices matter – keeping combustible materials too close to walls can accelerate fire spread, reducing the effectiveness of fire separation.

What are some day-to-day fire separation tips?

While fire separation is often a design and construction consideration, small daily actions can still help minimise the risk of spread should a fire take hold.

• Keep fire doors closed. Propping them open reduces their ability to contain fire.
• Check for unsealed gaps. These can occur around cables, vents, or piping, especially after maintenance work.
• Store flammable materials properly. Avoid stacking paper products near walls and store flammable liquids according to safety guidelines.

Why does fire separation need ongoing maintenance?

Even well-designed fire separation can become ineffective over time without proper maintenance. Fire-rated walls and structures can deteriorate and essential fire-stopping features can be accidentally removed or damaged during renovations or general use.

“Fire doors, for example, need to be inspected every six months, and fire dampers require checks every four years to ensure they still function as designed,” said Sullivan.

“When working with customers, we often find issues like unsealed openings in firewalls, unprotected ducting and vent work, or doors that aren’t actually fire-rated. That’s why regular inspections and maintenance are so important, they can help identify and address potential risks ahead of time.”

Whose responsibility is fire separation?

In commercial buildings, the building owner is typically responsible for ensuring fire separation is in place and maintained. This includes meeting fire safety regulations and submitting the required annual fire safety statement.²

However, tenants also play a role, especially if they make modifications to the building.

“Ultimately, the building owner is responsible for fire separation. But if a tenant is undertaking renovations for example, they need to make sure any penetrations—like cabling or ductwork—are properly sealed. Otherwise, they could be creating fire risks without realising it,” said Sullivan.

Strengthen your fire protection plan with insurance

Even with the right fire separation measures in place, fires can still happen – and when they do, they can result in significant property damage, loss of stock or equipment and interruption to your business operations.

After an event, your insurance can help get you back to the position you were in previously. Of course, this means having the right asset values in place – and if your business is affected, having a business continuity plan will also help you to get back on your feet faster.

Learn more about QBE’s Commercial Property insurance for medium and large businesses.

QBE Commercial Property insurance

¹ Fire Rescue Victoria, Home fire safety booklet
² Department of Planning and Environment, Fire safety statements FAQs