How do fire door manufacturers test fire resistance?

Fire door manufacturers test fire resistance through standardized fire performance tests conducted in certified laboratories. These tests involve exposing the door assembly to extreme heat in a controlled environment, simulating real fire conditions. The door is evaluated for how long it can withstand fire, prevent flame spread, and maintain structural integrity—typically rated for 30, 60, 90, or 120 minutes. Manufacturers follow national and international standards like BS 476, EN 1634, or UL 10C. In addition to fire exposure, some tests also assess smoke control. Only doors that pass these rigorous tests receive certification, ensuring they meet safety and building code requirements.