Fire Rating of Steel Doors Compared to Other Materials

July 18, 2023

 


Fire-rated assembly doors play a vital role for commercial buildings. These doors not only save lives by slowing down the spread of smoke and fire, but also provide a safer way for people to exit the building. That’s why the choice of material for both interior and exterior doors is an important consideration for almost any project.  

To help make the right choice on your next commercial building project, let’s explore the fire rating of steel doors and how it compares to other materials.  

What to Know About the Fire-Rating of Steel Doors

While a variety of doors can be fire-rated, hollow metal is the only material that is regularly granted a three-hour label. To reach this label in testing, the door, frame, opening size, jamb depth, and assembly work together to provide reliable protection in the event of a fire. In fact, one of the best options for commercial building projects are steel temperature rise doors.  

Temperature rise doors are designed to reduce the transfer of heat on the cooler side of the entryway. By capping the rate of heat transfer, people in the building can more safely pass through a fire’s point of origin. It’s one of the reasons why temperature rise doors are often used in stairwells. These types of steel doors come with a range of heat transfer ratings, with the lowest preventing the unexposed side of door from getting hotter than 250 degrees.  

How Other Common Door Materials Compare to Steel

Now that we have a baseline on the fire-rating of steel doors and frames, let’s look at how the other materials used for commercial building projects compare.   

  • Fire-Rating of Wood Doors: On average, wood doors have a fire-rating of 90 minutes compared to the three hours of steel. It’s also worth noting that wood is often more costly to use on projects that call for fire rated doors. That’s because wood might require the use of intumescent seals and a 5-inch metal edge to be installed where the door meets the jamb. Typically, the cost of wood doors will increase the higher the fire-rating, with 90-minute ratings being the most expensive.  

  • Fire-Rating of Aluminum Doors: Aluminum doors are popular in certain projects like retail business that are designed with glass storefronts. The fire-rating of aluminum is also 90-minutes and is more durable than wood.  However, these types of doors and frames don’t have much installation flexibility in the field. One of the main reasons behind this is because aluminum frames are extruded using dies during manufacturing process. This process limits the customization options for the doors and frames on your project.  

  • Fire-Rating of Fiberglass Doors: While fiberglass is more durable than wood and aluminum doors, it still has the same fire-rating of 90-minutes. Fiberglass doors will often require an intumescent seal to reach that fire-rating. Since the material is difficult to trim, it can get costly to have them specially made for commercial building projects.  

What’s the Best Fire-Rated Door and Frame Material for Your Building Project?

When you need fire-rated doors for a commercial building project, steel is the best choice in many situations. Not only does it have the longest fire-rating out of the materials we’ve covered but can also be easily customized to meet any specific need. For example, many steel door and frame manufacturers offer a variety of cores like steel stiffened or temperature rise to help manage heat transfer during a fire.  

The hardware like the hinges, pivots, closers, and locks that go into a steel door are also fire-rated, which isn’t always the case for other materials. If you’re interested in learning more about the value of fire-rated steel doors and frames offer your project, HMMA is here to help.  

Learn More About Fire-Rated Steel Doors and Frames Today

HMMA is here to provide resources to learn more about fire-rated steel doors and frames. We have a fire-rating AIA continuing education course and a variety of specs to help you make the best decision for your commercial building projects.