Intumescent seals are a critical component of any compliant fire door set, designed to protect lives and property in the event of a fire. These seals are typically installed along the edges of the door frame—on both vertical stiles and across the top head of the door. Under normal conditions, they remain inactive, allowing the door to function like any standard door.
When exposed to extreme heat—usually between 180°C and 200°C—the intumescent seals rapidly expand, often growing up to 20 times their original size. This expansion seals the gaps around the door, forming a tight, heat-resistant barrier that helps block the passage of flames, hot gases, and smoke.
This crucial containment slows the spread of fire, buying valuable time for occupants to evacuate safely and for firefighters to respond. To ensure ongoing fire protection, regular inspection and maintenance of intumescent seals is essential. Damaged, worn, or missing seals should be replaced immediately to maintain the full integrity and performance of your fire door set.
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