Intumescent strips are a crucial component of fire safety systems, particularly in fire doors. This comprehensive guide covers everything you need to know about intumescent strips, including their function, installation, and maintenance.
What Are Intumescent Strips?
Intumescent strips are materials that expand significantly when exposed to high temperatures, such as those experienced during a fire. They are typically installed in the edges of fire doors or around door frames. These strips are made from intumescent materials.
Intumescent strips are typically made from materials such as graphite or sodium silicate, which are known for their ability to expand significantly when heated.
How Do Intumescent Seals Work?
When exposed to heat, intumescent materials undergo a chemical reaction that causes them to expand many times their original size. This process is known as intumescence. As the strips expand, they fill any gaps between the door and the frame, or around the edges of the door. This creates a barrier that blocks the passage of fire, smoke, and hot gases.
How Much Fire Protection is Given by an Intumescent Strip?
The effectiveness of a fire door in resisting fire is significantly compromised without intumescent strips. By sealing these gaps, intumescent strips help maintain the integrity of the fire door assembly, ensuring that it can effectively prevent the spread of fire for a specified period, typically 30, 60, or 90 minutes, depending on the rating of the door and strips.
Do All Fire Doors Need Intumescent Strips?
In most cases, fire doors require intumescent strips to ensure they perform effectively in preventing the spread of fire and smoke. However, the specific requirement for intumescent strips can depend on the type and rating of the fire door, as well as applicable building regulations and standards.
Are There Any Regulations Around Intumescent Strips?
Fire safety regulations and building codes often require the installation of intumescent strips in fire doors to comply with standards such as BS 476: Part 22 or BS EN 1634-1.
What’s the Difference Between Intumescent Strips and Smoke Seals?
Intumescent strips are designed to expand when exposed to high temperatures, typically above 200°C (392°F). This expansion seals gaps around the fire door, preventing the spread of fire and hot gases.
Intumescent strips are usually fitted into grooves along the edges of the door or frame. They can also be surface-mounted depending on the design of the fire door.
Smoke seals are designed to prevent the passage of smoke and toxic gases through the gaps around fire doors. Smoke can spread rapidly and is often more dangerous than the fire itself because it can impair visibility and cause respiratory issues.
Smoke seals create a physical barrier that prevents smoke from passing through the gaps around the door. They typically provide an immediate seal without the need for activation by heat. They are often made from flexible materials such as rubber, silicone, or neoprene, which can create a tight seal even when the door is closed gently.
They are typically installed around the perimeter of the door leaf or frame, either in combination with intumescent strips or as a standalone component. They are designed to compress when the door is closed, ensuring a tight seal.
What are Combination Strips?
In many modern fire doors, intumescent strips and smoke seals are combined into a single product to provide comprehensive protection against both fire and smoke. These combination strips simplify installation and ensure that both aspects of fire door performance are addressed.
Can You Paint Intumescent Strips?
You can paint intumescent strips, but you cannot paint intumescent strips if they have a combined smoke seal. Stand alone smoke seals cannot be painted.
Can You Install Intumescent Strips Yourself?
Proper installation is crucial for the strips to perform effectively in the event of a fire. It is important that the same method for that door is used as per its original design and test standard.
The regulations require that the responsible person appoint a competent person to perform this task to ensure they have met their legal requirement. Engaging in third party accredited companies is a sure way of checking competency
Do Intumescent Strips Ever Need Replacing on a Fire Door?
Intumescent strips on fire doors do need replacing under certain conditions such as physical damage, wear and tear, contamination, incorrect installation, or degradation over time. Regular inspection and maintenance are critical to ensure these strips remain effective in providing fire protection. If you are unsure about the condition of your intumescent strips or how to replace them, it is advisable to consult a fire safety professional. If you’d like more information on this, you can get in touch with us here.
How Do You Know When You Need New Intumescent Strips?
Signs That Intumescent Strips Need Replacing
- Physical Damage:
- Cracks or Splits: If the intumescent strips have visible cracks, splits, or other forms of physical damage, they will not be able to expand properly in the event of a fire.
- Peeling or Detached: Strips that are peeling away from the door or frame or have become detached need to be replaced to maintain their effectiveness.
- Wear and Tear:
- Worn Down: Over time, regular use of the door can wear down the intumescent strips, reducing their effectiveness.
- Compression Damage: Strips can become permanently compressed if the door is frequently closed with excessive force, compromising their ability to expand when needed.
- Contamination:
- Paint or Dirt: If the strips are covered in paint, dirt, or other contaminants, they may not function correctly. Cleaning might be an option, but heavily contaminated strips should be replaced.
- Incorrect Installation:
- Improper Fit: Strips that were incorrectly installed or are the wrong size for the door may not provide adequate protection and should be replaced with correctly sized and installed strips.
- Age and Environmental Factors:
- Degradation Over Time: Intumescent materials can degrade over time, especially if exposed to adverse environmental conditions such as high humidity or extreme temperatures. Even if they appear undamaged, older strips may need replacing.
- Exposure to Chemicals: Certain chemicals and cleaning agents can damage intumescent strips, necessitating their replacement.
Regular Inspection and Maintenance
Regular inspection of fire doors, including the intumescent strips, is essential. This should be part of a broader fire door maintenance program. Here are steps to ensure they remain effective:
- Visual Inspections: Conduct regular visual inspections (at least every six months) to check for any signs of damage or wear.
- Functional Tests: Ensure that doors close properly and that the strips create a proper seal without obstruction.
- Professional Assessments: Engage a qualified professional to perform detailed inspections and maintenance annually or more frequently if the doors are in high-traffic areas.
By preventing the spread of fire and smoke, intumescent strips help protect building occupants, providing critical time for evacuation and reducing the risk of injury or death. Effective fire containment also helps limit damage to property and can significantly reduce the overall impact of a fire incident. If you’re unsure of what your next steps should be when it comes to fire safety, you can get in touch with us here and we can help you decide on the right course of action.
