How Fire Rated Doors are Made and Tested

Below is a transcription of this video, which was created by the Steel Door Institute.

Today, I’ll be talking about fire-rated doors, including door cores, door construction methods, and the inspection process. Plus, I’ll have a video of an actual fire test for you. Come on; I’ll show you how it’s done.

Three of the most commonly specified cores in fire-rated doors are honeycomd, steel stiffe, and polystyrene. The honeycomb core door is a real simple paper honeycomb core that’s bonded to the steel sheet. The second and second most common one is the steel stiffen door where the steel stiffeners are spot-welded to the steel skin. The third is the polystyrene. However, this door here, because it’s a full glass door, has very little polystyrene in it but we will see this one fire-tested later on in this video.

The testing process can’t begin until the internationally recognized testing agencies send their inspectors out to the review the doors prior to them being assembled. So, they will come out and inspect the cores, the materials, the bonding agents and glues, the steel stiffeners, etc. So, they will come out and inspect all these doors, measure, and document all the door construction prior to them being assembled. Once they’re fully assembled, the inspector will initial and sign off that he wants the assembly of these doors before they go off to the testing laboratory for the fire test.

A fire test must be conducted by an internationally recognized independent testing laboratory. Ratings are given in time increments from 20 minutes to three hours. As the test progresses, the temperature is steadily increased to simulate conditions of a real fire. As you can see, the door is securely positioned in front of the furnace. The furnace is strictly controlled and is continuously monitored for temperature and pressure. The furnace gets extremely hot, reaching up to 1500 degrees in less than 30 minutes. At 90 minutes it reaches 1750 degrees, and then at three hours, it’s more than 1900 degrees. The test isn’t complete until the host stream testing portion of the test is completed.

When you purchase a fire-rated door from an SDI member, you know that your product will meet your specifications, delivering the safety and durability that only a steel door can deliver.

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Updated on November 29, 2023

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