Fire Doors FAQs

What are fire-rated doors, and how do they work?

Fire-rated doors are specially constructed doors designed to slow or stop the spread of flames, smoke, and heat during a fire. They consist of various materials such as wood, steel, fiberglass, and fire-rated glass. These doors are part of fire-rated assemblies, including the door, frame, hardware, glazing, and other components that work together to provide fire protection.

What is the purpose of fire-rated doors?

Fire-rated doors serve as crucial elements in passive fire protection systems, helping to protect occupants by providing safe passage out of a building during a fire. When installed correctly, these doors remain closed and resist combustion for a specific duration, typically ranging from 20 to 180 minutes, based on code requirements.

Where are fire-rated doors commonly used?

Fire-rated doors are more commonly found in commercial buildings, especially in areas of egress such as lobbies, stairwells, storefronts, and exits. They are essential to meet code requirements and enhance occupant safety.

What components make up a fire-rated door assembly?

A fire-rated door assembly consists of multiple components, including the door, frame, hardware, glazing, and other necessary parts. While these components don't have to be from the same manufacturer, they must be classified and labeled for use in a fire door assembly.

Are there different types of fire-rated doors?

Yes, there are different types of fire-rated doors, such as fire-protective and fire-resistive doors. Fire-protective doors are designed to limit the spread of smoke and flames, while fire-resistive doors offer more extensive protection against radiant and conductive heat transfer.

How can I identify if a door is fire-rated?

To identify a fire-rated door, look for a fire label from an approved testing agency on the door. The label is usually located on the hinge side or top/bottom of the door. Underwriters Laboratories (UL) and Warnock Hersey (WH) are common approved agencies.

What happens if a fire-rated door is modified?

Modifying a fire-rated door with non-fire-rated hardware can nullify its fire rating. Any modifications must adhere to the testing requirements and criteria stated on the fire-rated door label.

Can fire-rated doors have glass components?

Yes, modern fire-rated doors often include fire-rated glass to promote visibility and daylight within the building. Fire-rated glass doors have labels specifying their fire- and life-safety characteristics.

What tests do fire-rated doors undergo?

Fire-rated doors undergo rigorous tests conducted by independent laboratories to achieve fire ratings and supplemental life safety and security ratings.

What is the acceptable gap between leaves on a pair of exterior steel doors?

The maximum clearance between the door and frame for both single swing and pairs of doors is 1/8". Weather-stripping should be provided to seal the perimeter and meeting edge of the opening.

How should the size of leaves be indicated in a schedule?

For unusual dimensions in a pair of doors, specify the dimensions of both leaves. For example, if one leaf is 3'0" wide, and the overall opening is 5'6", state the dimensions of both leaves since they are different sizes.

Can an excessive gap between meeting edges of a pair of doors be remedied with an astragal?

For non-rated doors, the end user or architect may approve clearances greater than 3/16", but it's essential to consider security and appearance. For rated openings, the maximum clearance allowed is 3/16" per NFPA 80, regardless of an astragal.

What is the tolerance on door width for steel doors?

The +/- 3/64” tolerance on door width is determined from the manufacturer's net dimension. It can vary depending on the manufacturer's design, but the tolerances should still fall within NFPA 80 guidelines.

Why choose steel doors for exterior openings over aluminum?

Steel doors offer a wider selection of builders' hardware and more diverse options for fire ratings compared to aluminum doors.

What is the preferred protective coating for grouted frames?

A quality bituminous coating should be applied to the throat of the frame.

What is the difference between face welding and a full profile weld in steel doors?

Face welding is applied only to the face of the frame, usually at the 45-degree joint. Full profile weld is applied to the full contour of the frame at the intersection of the head and jambs. Full profile welding is often used for cosmetic appearance and ease of installation but is not always necessary.

Is galvannealed steel preferable to galvanized steel for fire-rated doors?

Yes, galvannealed steel is preferred due to its better corrosion resistance and paint adhesion properties compared to galvanized steel.

Can fire-rated doors be used in residential structures?

While fire-rated doors are more common in commercial buildings, they can be utilized in residential structures, particularly in specific areas where enhanced fire protection is needed.

Do fire-rated doors require specialized maintenance?

Yes, fire-rated doors should be properly maintained to ensure they continue to function as intended during a fire. Regular inspections, lubrication, and repairs are essential to maintain their fire-rated capabilities.

Who can assist in determining the appropriate fire-rated doors for specific applications?

Consult with a fire safety expert, architect, or local Authority Having Jurisdiction (AHJ) to determine the suitable fire-rated doors for your building's specific needs and to comply with local codes and regulations.