Do Staircase Doors Leading to Rooftops and Outdoors Need to Be Fire Doors?

Do Staircase Doors Leading to Rooftops and Outdoors Need to Be Fire Doors?

This question has long been a topic of debate within the industry, generally categorized into three perspectives:

1. All doors must be fire doors.
2. Fire doors are required for enclosed staircases and smoke-proof staircases, but there are no specific regulations regarding doors leading to rooftops and outdoors.
3. Rooftops should have fire doors, while ground-level doors to the outdoors can be standard doors, as outdoor areas are deemed safe, eliminating the need for fire doors. Conversely, rooftops are not entirely safe and require fire doors to ensure security.

Arguments Supporting All Doors as Fire Doors

Regulations stipulate the following for enclosed staircases (6.4.2):

• For high-rise buildings, crowded public buildings, and multi-story factories classified as types A and B, the doors of enclosed staircases must utilize Grade B fire doors that open in the direction of evacuation. Other buildings may use double-action spring doors.
• The ground level of a staircase may include hallways and lobbies to form an expanded enclosed staircase, but these should also use Grade B fire doors to separate them from other hallways and rooms.

For smoke-proof staircases (6.4.3):

• Doors leading from evacuation corridors to lobbies and from lobbies to staircases must utilize Grade B fire doors.
• Except for lobbies in residential buildings, no other doors, windows, or openings should exist on the walls of smoke-proof staircases and lobbies, aside from evacuation doors and air inlets.

Key Points:

1. The regulations do not explicitly state that staircases can be without fire doors; thus, the absence of fire doors lacks regulatory support.
2. If a staircase uses pressurized ventilation, standard doors cannot ensure automatic closure and seal integrity, leading to pressure loss and ineffective smoke control.

Arguments for Fire Doors Leading to Rooftops

1. Safety Exits: Doors from staircases leading to rooftops and outdoor staircases are safety exits for personnel evacuation.
   • The term “indoor safe areas” includes refuge floors and corridors as per regulations, while “outdoor safe areas” cover outdoor ground, accessible rooftops meeting evacuation requirements, and bridges/corridors complying with the standards outlined in 6.6.4. Although refuge corridors are considered indoor safety zones, their safety differs from outdoor ground; thus, safety exits should directly access the outdoors to minimize the need for additional evacuation routes through refuge corridors.
2. From the definition of safety exits, doors leading to ordinary rooftops are not considered safety exits. Thus, ordinary rooftops are not classified as safe areas (generally understood as rooftops accessible to fire engines being safe), necessitating fire door installation for separation. Conversely, doors leading directly outdoors connect to safe areas and do not require fire doors.

However, a contradiction arises: If rooftops are not safe, what purpose do fire doors serve there?

Arguments Against Fire Doors

1. Regulations stipulate the need for doors at the entrances of enclosed staircases to prevent smoke and heat from entering.
2. Smoke-proof staircases should include facilities like ventilated lobbies or balconies, ensuring that doors leading to lobbies and staircases are fire doors to block smoke and heat ingress.
3. According to 6.4.1, evacuation staircases must be naturally lit and ventilated, ideally positioned against exterior walls. Windows on these walls must maintain a horizontal distance of at least 1.0m from nearby doors and openings.

Interpretation: In the event of a fire, smoke and heat from a fire on either side of the staircase may spread through openings in the external walls into the staircase. This regulation requires a minimum distance between stairwell windows (including those in the lobby or shared lobby) and the nearest edge of adjacent doors, windows, or openings to ensure smoke and fire do not invade the evacuation staircase.

1. The terminology for enclosed staircases and smoke-proof staircases emphasizes the requirement for doors leading to staircases to prevent fire smoke and heat from entering; hence, doors leading to rooftops and outdoors should be considered exit doors rather than “staircase entrances.”
2. Doors leading to rooftops and outdoors correspond to exterior walls; thus, doors on the stairwell’s exterior wall are often standard windows. According to 6.4.1, only when the distance between external windows and adjacent doors and openings is less than 1.0m is the installation of fire-resistant windows required. Therefore, equipping exterior stairwell doors with fire doors seems redundant if the external windows are standard.
3. Insights from 6.4.2 and 6.4.3 highlight that regulations regarding fire doors in staircases and expanded staircases mainly emphasize isolation from other indoor spaces to ensure staircase safety, without explicit requirements for outdoors.
4. For staircases utilizing natural smoke ventilation, the absence of pressure concerns means that, provided the 1.0m requirement is met, there’s theoretically no increased safety risk by not installing fire doors on exits to rooftops or outdoors. This raises the question: can these external doors be eliminated entirely?
5. In staircases using pressurized smoke prevention, to maintain positive pressure, exterior windows are typically fixed and non-opening. If standard doors are installed, they should include automatic closing mechanisms or utilize the regulation’s suggestion of “double-action spring doors” to ensure the door’s seal.

Additional Considerations

Throughout our discussion, a more pressing issue emerged: several colleagues shared that the doors leading from their staircases to rooftops are often locked by property management for various reasons, such as concerns over children playing, fears of people jumping, worries about items being thrown from heights, or potential break-ins via rooftops. Some managers flexibly open these doors during the day for airing out but lock them at night for security.

Optimal Design Recommendations

According to Shanghai’s Residential Design Standards (DGJ08-20-2013):

• At least one staircase should lead to a rooftop platform, preferably with a standard glass door opening toward the roof.

As per Jiangsu’s Residential Design Standards (DGJ32/J26-2017):

• Staircases in residences should lead to rooftops, with doors or windows being standard glass types that open outward.

Coastal regional regulations provide an excellent reference for practice, emphasizing the use of “standard” glass doors and windows. This implies the avoidance of laminated safety glass that could hinder emergency access.

Standard glass doors and windows not only ensure compliance with fire safety regulations but also facilitate quick evacuation in emergencies, even if doors are locked.

Final Thoughts

1. For staircases utilizing natural smoke ventilation, standard doors can be employed.
2. For pressurized staircases, installing standard doors should include automatic closing devices or “double-action spring doors,” ensuring door integrity.
3. For both outdoor and rooftop exits, the use of standard glass doors is highly recommended.