Fire safety in buildings often relies on seemingly small components that play a crucial role during emergencies. One such element is intumescent strips, a simple yet highly effective fire protection measure commonly installed in fire doors and partitions. These strips might not look like much, but when a fire occurs, they can mean the difference between life and death. This blog explores how intumescent strips work, their importance, and how they enhance fire safety.
What Are Intumescent Strips?
Intumescent strips are narrow bands made from fire-resistant material designed to be installed along the edges of fire doors, partitions, or glazing systems. These strips are heat-activated, meaning they expand when exposed to high temperatures during a fire. The expansion creates a tight seal that blocks flames, heat, and smoke from spreading to other parts of the building.
They are a key part of passive fire protection systems, designed to contain fires within a specific area, allowing occupants more time to evacuate and reducing damage to the building.
How Do Intumescent Strips Work?
Intumescent strips are made from materials like graphite, sodium silicate, or other compounds that react to heat. When temperatures rise to a certain point—typically around 200°C or higher—the strips begin to expand, often by up to 20 times their original size. This rapid expansion fills the gaps around a fire door or partition, sealing off the area to prevent:
- The Spread of Flames: By blocking gaps, intumescent strips stop flames from moving through doors or partitions into adjacent rooms.
- Smoke Infiltration: Smoke is one of the leading causes of injuries and fatalities during a fire. Intumescent strips with added smoke seals prevent smoke from escaping, ensuring clear escape routes for occupants.
- Heat Transfer: The seal also slows the transfer of heat, giving additional protection to occupants and property on the other side of the door or partition.
Why Are Intumescent Strips Important?
While fire doors and partitions are designed to resist fire, they are only effective if the gaps between the door and the frame—or the edges of a partition—are sealed. Without intumescent strips, these gaps allow fire and smoke to bypass the protective barrier, compromising its integrity. Intumescent strips are essential for several reasons:
1. Enhancing Fire Door Performance
Fire doors are rated for specific time durations, such as 30, 60, or 120 minutes. Intumescent strips help these doors achieve their rated performance by preventing fire and smoke from passing through.
2. Ensuring Safe Evacuation
By blocking smoke and flames, intumescent strips keep escape routes like stairwells and corridors safer and more navigable for longer, allowing occupants to evacuate safely.
3. Complying with Regulations
In the UK, building regulations require fire doors and partitions to meet strict fire resistance standards. Intumescent strips are a critical component of compliance, ensuring that these elements perform as intended during a fire.
4. Protecting Property and Lives
Containing a fire in its place of origin limits the damage to property and gives firefighters more time to extinguish the flames before they spread further.
Where Are Intumescent Strips Used?
Intumescent strips are commonly installed in the following locations:
- Fire Doors: Along the edges of doors and door frames to seal gaps when the door is closed.
- Partitions: In gaps where walls or ceilings meet partitions, particularly in office buildings and industrial facilities.
- Glazing Systems: Around fire-resistant glass to prevent fire and smoke from passing through the frame.
- Lift Shafts: To seal gaps around lift doors, stopping smoke from travelling between floors.
Types of Intumescent Strips
There are several types of intumescent strips available, each designed for specific applications. The most common include:
1. Plain Intumescent Strips
These are simple strips that expand when exposed to heat, used mainly for blocking fire and heat.
2. Intumescent Strips with Smoke Seals
These strips combine fire protection with smoke sealing, featuring additional brushes or rubber fins to block smoke during a fire.
3. Surface-Mounted Strips
Ideal for retrofitting existing fire doors or partitions, surface-mounted strips can be applied without major modifications.
4. Concealed Intumescent Strips
Installed within grooves cut into the door or frame, these strips are less visible but just as effective.
Installation and Maintenance Tips
Proper installation and regular maintenance of intumescent strips are essential to ensure they work when needed.
Installation
- Placement: Ensure the strips are installed along the entire perimeter of the door or partition, with no gaps or overlaps.
- Correct Sizing: Choose strips that fit snugly into the gaps they are meant to seal. Strips that are too small or too large will not work effectively.
- Professional Help: For best results, consider hiring a fire safety professional to install the strips, especially in commercial or high-risk settings.
Maintenance
- Regular Inspections: Check the strips for signs of wear, damage, or detachment. Replace any damaged strips immediately.
- Keep Gaps Clear: Ensure that nothing obstructs the gaps around fire doors or partitions, as this can prevent the strips from expanding.
- Test Fire Doors: Regularly test fire doors to ensure they close properly, as misalignment can compromise the performance of intumescent strips.
The Big Impact of a Small Addition
Intumescent strips may be small, but their role in fire safety is immense. By expanding to block smoke, heat, and flames, these strips enhance the performance of fire doors and partitions, providing critical protection during an emergency. Whether you’re outfitting a new building or upgrading existing fire safety measures, investing in high-quality intumescent strips is a small step that can make a big difference.
For expert advice on intumescent strips and other fire protection solutions, contact Martyn Young Fireproofing Consultancy today.