The momentum and speed at which a fire can spread inside a building shouldn’t be underestimated. Fires are very difficult to control, particularly if not contained initially, which is why it’s so important to select quality construction materials that will protect occupants in such an emergency.

Fire rated doors not only play a key role in protecting people, but also in minimizing property fire damage. Hollow metal doors and frames are very effective and are composed of the only material widely available with a 3-hour fire rating.

Here’s some helpful information for selecting the proper fire rated doors and frames for your project:

1. The fire rating classification of the wall into which the door is installed dictates the required fire rating of the door. Steel fire doors are rated by the time a door can withstand exposure to fire test conditions.

2. 3-hour rated fire doors are usually required in walls that separate buildings or divide a large building into smaller areas. (The wall rating is 4 hours.)

3. 1-1/2-hour rated fire doors are required in 2-hour rated walls. They are commonly located in stairwells or other enclosures in a building. They’re also in boiler rooms and exterior walls that pose the risk of severe outside fire exposure.

4. 45-minute rated fire doors are used in 1-hour walls and are required in walls of corridors and room partitions. They may also be installed in exterior walls that are subject to moderate outside fire exposure.

5. 20-minute rated fire doors are used in 1-hour walls for corridor applications and other areas where smoke and draft control is a key concern.