Passive fire protection is the range of fire safety measures built into the structure and fabric of a building to help contain fire and smoke and prevent them from spreading rapidly from one area to another.
Unlike active fire protection systems, such as fire alarms and sprinklers, passive fire protection does not generally need to be manually or automatically activated. Instead, measures such as fire-resistant walls and floors, fire doors, fire stopping and intumescent materials are incorporated into a building to help maintain its fire resistance.
Effective passive fire protection can protect escape routes, give occupants more time to evacuate, reduce damage to a building and help prevent a fire in one area from spreading throughout the premises.
How does passive fire protection work?
A fundamental principle of passive fire protection is compartmentation.
Rather than allowing fire and smoke to move freely throughout a building, the premises can be divided into separate fire-resistant compartments. Walls, floors, doors and other barriers are designed to resist fire for a specified period and restrict its movement from one area to another.
However, these compartments need to remain intact to work effectively. Openings created for doors, pipes, cables, ventilation systems and other building services can provide routes through which fire and smoke can spread if they are not appropriately protected.
Passive fire protection therefore encompasses several different systems that work together to maintain the fire resistance of the building.
What does passive fire protection include?
The passive fire protection required will depend on factors including the building’s construction, use, layout and fire strategy. Common measures include the following:
Fire compartmentation
Fire compartmentation divides a building into separate areas using fire-resistant walls, floors and other construction.
The objective is to contain fire and smoke within a defined area for a specified period rather than allowing it to spread rapidly throughout the building.
Effective compartmentation can help protect escape routes, reduce the number of people immediately exposed to a fire and limit damage to other areas of the premises.
Compartmentation can become compromised over time, particularly when alterations are made to a building. New electrical cables, pipework, ductwork and other services may pass through fire-resistant walls or floors and create openings that need to be appropriately fire stopped.
Fire stopping
Fire stopping is used to seal openings, joints and penetrations in fire-resistant walls and floors so that the required level of fire resistance is maintained.
For example, pipes, electrical cables and ducts frequently need to pass between different areas of a building. The spaces created around these services could allow fire and smoke to move between compartments.
Suitable fire-stopping systems are installed around these penetrations to reinstate the integrity of the fire-resistant construction.
Depending on the application, this can include products such as:
- Fire-resistant sealants
- Pipe collars and wraps
- Fire compounds
- Fire pillows and pads
- Fire-resistant boards
- Cavity barriers
The correct solution depends on the construction, service penetration and required level of fire resistance, so fire-stopping products should be appropriately specified and installed rather than simply used to fill a visible gap.
Fire doors
Fire doors are another important part of a building’s compartmentation.
They are designed to resist the passage of fire and, where applicable, smoke for a specified period while still allowing people to move through the building during normal use.
A fire door is a complete system rather than simply a fire-resistant door leaf. Its effectiveness can depend on the door frame, hinges, glazing, seals, self-closing devices and other components being correctly specified, installed and maintained.
Damage, excessive gaps, defective seals or a door that does not close correctly can compromise its performance, which is why appropriate inspection and maintenance are important.
Intumescent products
Intumescent materials react when exposed to high temperatures by expanding significantly beyond their original size.
This expansion can help seal openings and restrict the movement of fire, smoke and hot gases.
Intumescent materials are used in a variety of passive fire protection applications, including fire door seals, pipe collars, wraps and protection for structural elements.
Fire and smoke barriers
Fire and smoke barriers are used to restrict the movement of fire and smoke through concealed or open areas of a building.
They can form an important part of the overall compartmentation strategy, particularly where large or concealed spaces could otherwise provide a route for fire and smoke to spread beyond the area in which a fire started.
Structural fire protection
Some structural elements may also require protection to help them retain their load-bearing capacity during a fire.
Steel, for example, does not need to burn to lose structural strength. As its temperature rises, its ability to support loads can reduce significantly.
Depending on the building and its fire strategy, structural steel can therefore be protected using systems such as intumescent coatings, fire-resistant boards or other suitable materials designed to delay the effects of high temperatures.
What is the difference between active and passive fire protection?
Active and passive fire protection perform different but complementary roles.
Passive fire protection is primarily concerned with the construction and subdivision of the building. Measures such as compartmentation, fire doors and fire stopping help restrict the movement of fire and smoke.
Active fire protection generally involves systems that detect, warn of, control or suppress a fire and require some form of activation. Examples include:
- Fire alarms and detection systems
- Fire sprinklers
- Fire suppression systems
- Fire extinguishers
A comprehensive fire safety strategy will commonly incorporate both active and passive measures rather than relying exclusively on one or the other.
For example, a fire alarm can alert occupants to a fire while passive fire protection helps protect escape routes and restrict the spread of fire and smoke as people evacuate.
Why is passive fire protection important?
Passive fire protection can significantly influence how a fire develops within a building.
Without effective compartmentation, openings through walls and floors can allow flames, heat and smoke to spread beyond the area where the fire originated.
Appropriate passive fire protection can help to:
- Restrict the spread of fire and smoke
- Protect escape routes
- Provide occupants with more time to evacuate
- Maintain the integrity of fire-resistant compartments
- Protect structural elements
- Limit damage to other areas of a building
- Support an effective overall fire safety strategy
- Help building owners and responsible persons meet their fire safety obligations
Passive fire protection should therefore be considered alongside detection, alarms, firefighting equipment, evacuation procedures and other measures identified through the building’s fire risk assessment.
Why does passive fire protection need to be inspected and maintained?
One of the challenges with passive fire protection is that defects are not always obvious during the everyday use of a building.
A fire-resistant wall may initially have been correctly constructed, for example, but subsequent work could introduce new penetrations for electrical cables, data cabling, pipes or ventilation systems.
Fire doors can also become damaged or altered, while seals, closers and other components can deteriorate over time.
Building alterations and refurbishment work should therefore take existing fire compartments into account, and passive fire protection should be appropriately inspected and maintained.
Where defects are identified, remedial work may be necessary to restore the intended fire resistance of the building.
Who is responsible for passive fire protection?
Under the Regulatory Reform (Fire Safety) Order 2005, the Responsible Person has duties relating to fire safety in non-domestic premises in England and Wales.
Depending on the circumstances, this could include an employer, building owner, landlord, occupier, facilities manager or another person with control of the premises. Where more than one Responsible Person has duties for a building, they are required to cooperate and coordinate with one another.
Responsibilities include carrying out and regularly reviewing a suitable fire risk assessment and putting appropriate fire safety measures in place.
The exact passive fire protection measures required will vary between buildings, which is why fire safety measures should be based on the individual premises and its fire risk assessment rather than applying a single solution to every building.
How can you tell if passive fire protection is inadequate?
Some passive fire protection defects may be visible, although others can be concealed within the building.
Potential warning signs can include:
- Unsealed gaps around pipes, cables or ductwork
- Damage to fire-resistant walls or ceilings
- Fire doors that do not close fully
- Damaged or missing fire door seals
- Holes left following building or maintenance work
- Poorly sealed service penetrations
- Missing or damaged cavity barriers
- Previous alterations where the original compartmentation may have been disturbed
A specialist survey can provide a more systematic assessment of compartmentation and passive fire protection and identify areas where remedial work may be required.
Does every building need the same passive fire protection?
No. The appropriate passive fire protection measures depend on the individual building.
Factors such as its construction, size, layout, occupancy, use, escape strategy and existing fire safety measures can all affect what is required.
A warehouse, office, school, healthcare facility and residential development, for example, may have very different layouts and fire risks.
This is why passive fire protection should be properly assessed and specified for the individual premises.
Get help with passive fire protection
Effective passive fire protection relies on more than installing individual fire-resistant products. Fire doors, compartmentation, fire stopping, barriers and other measures need to work together to maintain the intended fire resistance of your building.
Thameside Fire Protection provides certified passive fire protection services across the UK, including compartmentation surveys, fire stopping, fire doors, fire and smoke barriers, intumescent products, remedial works, inspections and ongoing maintenance.
Our passive fire division holds LPS 1271 and LPS 1197 certification, providing independent assurance of our passive fire protection work.
Whether you need to assess existing compartmentation, rectify defects or install new passive fire protection measures, our experienced team can help identify what your building requires and provide an appropriate solution.
Learn more about our passive fire protection services.
FAQs
Is a fire door active or passive fire protection?
A fire door is a form of passive fire protection. It forms part of a building’s compartmentation and is designed to restrict the spread of fire and, where applicable, smoke between different areas.
What is the difference between fire stopping and compartmentation?
Compartmentation is the wider system of dividing a building into fire-resistant areas using elements such as walls and floors. Fire stopping is used to protect openings and penetrations within those compartment boundaries, such as gaps around pipes, cables and ducts.
What can compromise passive fire protection?
Building and maintenance work is a common cause. Installing new cables, pipes, ventilation or other services can create openings through fire-resistant walls and floors. Damage to fire doors, barriers and other components can also compromise the intended fire resistance, which is why inspection and maintenance are important.
Does passive fire protection need maintenance?
Yes. Passive systems can become damaged or compromised as a building is used, maintained and altered. Regular checks can help identify defects, while specialist surveys may be appropriate where there are concerns about compartmentation or other passive fire protection measures.