Opening New Doors: Rethinking Fire Protection with Oversized Entrances

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Oversized warehouse door and frame assemblies.
Oversized warehouse door and frame assemblies.

Fire safety regulations and standards have long been a deeply rooted practice in North America. While regular fire-rated door openings are widely available, options for fire-rated oversized doors are limited. Recognizing the need for oversized fire-rated doors AMBICO engineers designed AMBICO Oversized Fire Rated Doors.

As a longstanding expert in the industry, AMBICO understood the importance of oversized fire-rated doors, especially in industrial settings where the risk of fire incidents is higher. Environments that require large, oversized openings often contain valuable resources, large equipment, and/or numerous personnel, thus significantly increasing the need for fire protection on oversized doors.

AMBICO Oversized Fire-Rated Doors and Frames provide the accessibility and functionality required of oversized doors, as well as the protection of a fire-rated door opening. This blog, as the second in the oversized door series, will explore the importance of fire-rated performance in oversized doors, their features, and popular applications, along with insights into their testing standards.

The Significance of Fire Protection in Oversized Openings

Fire-rated doors are a crucial component of any fire separation system. They are specifically designed to prevent the spread of fire, providing a safe means of egress for building occupants. In industrial settings such as manufacturing facilities, warehouses, and power plants, where oversized doors are necessary, the importance of oversized fire-rated solutions is amplified. These environments house valuable assets, equipment, as well as large numbers of working personnel. Therefore, the doors installed in these environments require features that not only allow access to the space but also provide protection for the valuable assets, equipment, and, more importantly, help ensure the safety of personnel in the event of a fire.

AMBICO Oversized Fire-Rated Doors

AMBICO’s Oversized Fire-Rated Doors and Frames are engineered with precision to meet the highest standards of fire protection. They are available in sizes up to 5’x12’ for singles and 10’x12’ for pairs, offering up to 90 minutes of fire protection. These steel doors are constructed using special welded stiffened construction and insulated cores and can also be furnished with a temperature rise of 450° F at a 30-minute rating.

The fire-rated paired oversized assemblies are available either active x inactive or active x active, with a mullion splitting the door leaves. Additionally, oversized fire-rated doors can be constructed with vision lite; however, they are limited to sizes up to 100 sq. inches per vision lite.

To accommodate the size and weight of the oversized doors and frames, splicing may be required for certain configurations. Therefore, oversized frames may be shipped in pieces for site assemblies.

Overall, fire-rated oversized doors are not significantly different from regular oversized doors. What truly sets them apart is the stringent testing procedure they have undergone to offer precise and guaranteed fire protection. As they are similar in structure and overall configuration to regular oversized doors, they offer the same ease of operation and access, allowing them to cater to their environment and applications no differently than regular oversized doors.

Supported by Rigorous Testing Standards

AMBICO’s Oversized Fire-Rated Door and Frame assemblies are tested to NFPA 252, Standard Methods of Fire Tests of Door Assemblies, or UL 10 C, Standard for Positive Pressure Fire Tests of Door Assemblies.  Fire-rated door assembly testing includes the fire endurance test and hose stream test.

Learn more about our Fire-rated testing in our blog on Fire Rated Door and Frame Assemblies.

Beyond Industrial Applications

Oversized fire-rated doors commonly find use in industrial applications; however, it is not the only application for oversized fire-rated assemblies. While Oversized fire-rated openings are popular in manufacturing facilities, warehouses, and power plants with large equipment or machinery that require fire protection, they are also particularly well-suited for buildings with high occupant loads, such as theaters, stadiums, and convention centers.


Fire protection in door assemblies is a non-negotiable component of fire protection systems, and oversized doors will not be an exception. AMBICO is committed to providing durable and reliable fire-rated door solutions for large openings. Whether to protect valuable assets or ensure the life safety of occupants, AMBICO’s Oversized Fire-Rated Doors and Frames are a trusted solution for all fire protection needs.