What is passive fire protection?
Passive fire protection is the act of preparing a building to ensure that a fire can be contained and delayed by the design and structure of the building itself. In this sense, it’s passive because it doesn’t involve anyone doing anything at the time of the fire. Click on the graphic below to see where passive fire protection can be implemented.
Prevent gaps through air sealing, ensure compartmental rooms are safe from smoke.
Where you have cabling, ensure it is properly coated to avoid the spreading of flames and to preserve vital cables.
Apply special, chemically enhanced coatings to the walls to maximise the time people can stay in a compartment and allow for rescue while the fire is kept at bay.
Compartmentation divides a building so that a fire can be contained and managed over longer periods, providing safe spaces for people and assets.
These are placed inside air conditioning and heating ducts, closing when there is a high rise in temperature to seal off ducts and prevent the spread of smoke and fire.
Whether kept closed at all times or auto-closing, in the event of a fire, fire doors provide resistance to keep a fire contained and preserve exit routes.
Where doors or windows are used as part of containment of a fire, the glass in them must meet certain fire resistance levels.
Materials used as insulation will have different fire resistance ratings and can play a key role in preventing a fire spreading from room to room.
Air sealing, as a passive fire protection technique, simply reduces the number of ingress points for the smoke in the event of a fire. Smoke inhalation can kill just as easily as the fire itself, so by sealing off open gaps where cabling or pipework runs out of the room, you can keep the compartment safe from smoke for a longer period. These areas can be filled with cavity barriers, pipe collars and wraps, but might not be something you’ve thought of when it comes to fire safety.
To a lesser extent, this also keeps the flames themselves at bay if there is no easy path for them to spread through.
When a fire breaks out, it is easy for it to travel quickly along things like cables which run through multiple spaces or rooms, and can decimate essential cabling. With special fire-resistant cable coatings, the spread of flames is stopped and the integrity of an area is retained.
When the coating reacts to a fire, it expands and protects the cables inside. This often means that the cables are still usable after the fire and maintains power and service for a building.
Intumescent seals can be applied to walls as a coating which then expands in a fire to preserve the compartmentation of an area for longer. This then allows others to escape the building through safe exit routes. The coatings can be applied as a spray using a number of materials.
An important part of passive fire protection, compartmentation keeps the divided areas safe from the rapid spread of fire. By sealing off areas, the flames and smoke are held at bay, allowing for the people in the building to leave calmly and securely, as well as allowing the fire and rescue services to salvage more of a building.
Many businesses don’t have an alternative base to operate from, so preserving as much of their building and the assets within is key.
Many buildings will have connecting HVAC (Heating, Ventilation and Air Conditioning) systems, which could be an easy route for flames and smoke to spread quickly during a fire. Fire dampers can be put in place to prevent this, allowing for air and heat to be transferred normally until a rapid rise in heat, presented by a fire, causes the damper to close and shut off this route for smoke and flames.
One of the most well-known parts of passive fire protection, fire doors come in a variety of fire-resistance ratings depending on the composition of the materials used to build them and any additional components. In the event of a fire, these doors can be triggered to close automatically, helping to seal off areas of a building and preserve evacuation routes out of the building. The resistance to fire means they can withstand the heat and flames for longer periods when compared with normal doors.
Fire-resistant glass – sometimes called fire-rated glazing – comes in a variety of forms, but is intended to offer additional protection for compartments in the event of a fire. Withstanding heat and flames, whether built into a fire door as a window or as floor-to-ceiling glass, the specially designed glass provides a barrier which stops the spread of fire and smoke to preserve exit routes.
There are three main glass classifications when it comes to fire-resistant glass, all manufactured in different ways for different benefits:
- Integrity – Basic, only stops flames penetrating the glass
- Radiation Control – Stops both flames and heat
- Insulation – The most resistant, prevents flames and heat as well as a lower temperature for the side of glass not facing the fire
Due to specific materials used in the composition, insulation in your walls can add to your passive fire protection arrangements. From the boards to the padding within the walls, there are materials with a higher-than-average fire rating to help maintain compartments and protect evacuations routes from the spread of fire.
These non-combustible materials are also designed with toxic smoke in mind and, as such, don’t add to the danger when they come into contact with flames.