When Does a Door Need an Intumescent Seal?
Why Are Intumescent Seals Important?
Building regulations require that fire doors be equipped with intumescent seals to slow the spread of fire and smoke. Without these seals, the small gaps around a door and its frame would allow fire to spread rapidly, putting lives at risk.
Fire doors are designed to move freely within the frame, which means there must be a small gap around the perimeter. However, if this gap is too wide, the door may fail to contain fire and smoke effectively. Intumescent seals play a crucial role in preventing fire and smoke from spreading, helping to protect both property and lives.
How Do Intumescent Seals Work?
Intumescent seals are installed on either the door or the door frame. When exposed to heat, these seals expand to fill the gap between the door and the frame, preventing fire and smoke from passing through. This containment helps keep fire restricted to one room or compartment, giving occupants more time to escape and firefighters more time to respond.
How to Install an Intumescent Seal
Tools You’ll Need
Depending on your installation method, you may need the following tools:
Knife or scissors – For cutting the seal to size
Router – Needed only for rebated installation (option 2)
Clean, damp cloth – To remove dirt and grease before installation
Installation Methods
Option 1: Surface-Mounted Intumescent Seal (Attaches to the Door Frame)
This is the easiest and most common installation method.
Clean the door frame with a damp cloth to remove any dirt or grease.
Measure the height of the fire door and cut the intumescent seal accordingly, ensuring it aligns with the lock position.
Test fit the seal by placing it in position and opening/closing the door without adhesive.
Peel off the adhesive backing and attach the seal to the hinge side of the door frame.
Press firmly to ensure full contact with the frame.
Option 2: Rebated Intumescent Seal (Fits into the Door Itself)
This method requires a groove in the door to house the seal.
Measure the door height and cut the seal to the correct length.
Ensure a proper gap so the seal fits snugly while maintaining contact with both the door and frame.
Use a router to create a groove in the door and clean the surface.
Test fit the seal before affixing it by opening and closing the door.
Make necessary door adjustments if the seal is too tight or prevents the door from self-closing.
Fine-tune the door closer if needed, ensuring the seal allows the door to function properly without jamming.
What About Batwing Smoke Seals?
Batwing smoke seals are another option, providing both smoke and acoustic protection. They are typically installed along the corners of the door frame.
How to Install a Batwing Smoke Seal
Measure the frame (top and both sides) and cut the seal to fit.
Miter the corners for a precise fit.
Peel off the adhesive backing (one section at a time).
Firmly press the seal into place along the exact installation location.
Do not remove and relocate once installed.
Ensure the door operates smoothly without obstruction.
Final Thoughts
Fire protection is not just about compliance—it’s about safety. Installing intumescent seals is an essential step in making sure your fire doors perform effectively. Whether you opt for surface-mounted or rebated installation, a properly fitted seal can make all the difference in a fire emergency.
Would you like to explore different types of fire door seals for your project? Contact us today for expert guidance!
