Fire door - Revision history

Emma: Revise Basic article against FSE writing guidelines: sourced explanations, examples and references (GPT-6)

2026-11-02T18:42:08Z

Revise Basic article against FSE writing guidelines: sourced explanations, examples and references (GPT-6)

Emma: Revise Basic article against FSE writing guidelines: sourced explanations, examples and references (GPT-6)

2026-11-02T18:14:22Z

Revise Basic article against FSE writing guidelines: sourced explanations, examples and references (GPT-6)

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Sanne: Add diagrams fse-fire-door-v1.svg, fse-fire-door-v2.svg, fse-fire-door-v3.svg (level-1 visual plan)

2026-11-02T07:07:13Z

Add diagrams fse-fire-door-v1.svg, fse-fire-door-v2.svg, fse-fire-door-v3.svg (level-1 visual plan)

← Older revision		Revision as of 08:07, 2 November 2026
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	The door allows normal passage while preserving the separation during fire. Its rating and operation therefore depend on the complete installed assembly and on whether it actually closes in the scenario. A door leaf alone does not demonstrate performance of the opening.<ref name="CVM2-64" /><ref name="CVM2-14">Ministry of Business, Innovation and Employment (2025), p. 14.</ref>		The door allows normal passage while preserving the separation during fire. Its rating and operation therefore depend on the complete installed assembly and on whether it actually closes in the scenario. A door leaf alone does not demonstrate performance of the opening.<ref name="CVM2-64" /><ref name="CVM2-14">Ministry of Business, Innovation and Employment (2025), p. 14.</ref>
			[[File:fse-fire-door-v1.svg\|thumb\|upright=1.5\|alt=Fire door with labelled leaf, frame, intumescent seal, closer and latch in a fire separation.\|A fire door is a complete doorset, not only a leaf. Based on Ministry of Business, Innovation and Employment (2025), p. 64 and U.S. Nuclear Regulatory Commission (2005), p. C-9.]]

	Fire doors are not identical to smoke control doors. Fire doors with smoke-control capability must satisfy both sets of requirements in C/VM2, while smoke control doors have a specific smoke-control function and need not provide the same fire-resistance rating. The intended duty must be identified.<ref name="CVM2-64" /><ref name="NUREG-1805-F-19">U.S. Nuclear Regulatory Commission (2005), p. F-19.</ref>		Fire doors are not identical to smoke control doors. Fire doors with smoke-control capability must satisfy both sets of requirements in C/VM2, while smoke control doors have a specific smoke-control function and need not provide the same fire-resistance rating. The intended duty must be identified.<ref name="CVM2-64" /><ref name="NUREG-1805-F-19">U.S. Nuclear Regulatory Commission (2005), p. F-19.</ref>
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	C/VM2 assumes self-closing fire and smoke control doors are closed except when being used. At low occupant load it allows three seconds per occupant, while expected queuing keeps the door open for the queue duration. This creates a time-dependent boundary rather than a permanently closed one.<ref name="CVM2-14" />		C/VM2 assumes self-closing fire and smoke control doors are closed except when being used. At low occupant load it allows three seconds per occupant, while expected queuing keeps the door open for the queue duration. This creates a time-dependent boundary rather than a permanently closed one.<ref name="CVM2-14" />
			[[File:fse-fire-door-v2.svg\|thumb\|upright=1.5\|alt=Door opens for three seconds per occupant and remains open during a queue before closing.\|Fire-door state changes during evacuation. Based on Ministry of Business, Innovation and Employment (2025), p. 14.]]

	For bedrooms in care settings, smoke control doors without self-closers are considered closed once evacuation from the bedroom is complete. This is a specific modelling rule in C/VM2 and should not be applied to every occupancy. It illustrates how door state is linked to the evacuation scenario.<ref name="CVM2-14" />		For bedrooms in care settings, smoke control doors without self-closers are considered closed once evacuation from the bedroom is complete. This is a specific modelling rule in C/VM2 and should not be applied to every occupancy. It illustrates how door state is linked to the evacuation scenario.<ref name="CVM2-14" />
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	For most ratings, the door assembly is then subjected to impact, erosion and cooling from a hose stream. This tests performance after the fire-endurance period and shows that evaluation includes more than temperature exposure alone. The 20-minute assembly is an exception for which this step is optional in the cited summary.<ref name="NUREG-1805-C-9" />		For most ratings, the door assembly is then subjected to impact, erosion and cooling from a hose stream. This tests performance after the fire-endurance period and shows that evaluation includes more than temperature exposure alone. The 20-minute assembly is an exception for which this step is optional in the cited summary.<ref name="NUREG-1805-C-9" />
			[[File:fse-fire-door-v3.svg\|thumb\|upright=1.5\|alt=Door in furnace followed by hose-stream impact, erosion and cooling.\|Fire-door testing includes endurance and hose-stream response. Based on U.S. Nuclear Regulatory Commission (2005), p. C-9.]]

	NUREG-1805 also lists temperature increases of 121 °C, 232 °C and 343 °C, with no temperature rating indicating an increase above 343 °C on the unexposed surface after 30 minutes. These are source-specific test criteria and should not be used as universal door-safety temperatures.<ref name="NUREG-1805-C-9" />		NUREG-1805 also lists temperature increases of 121 °C, 232 °C and 343 °C, with no temperature rating indicating an increase above 343 °C on the unexposed surface after 30 minutes. These are source-specific test criteria and should not be used as universal door-safety temperatures.<ref name="NUREG-1805-C-9" />

Jan: Repair new FSE wiki article: Fire door (written by Kimi Code CLI)

2026-11-02T04:24:19Z

Repair new FSE wiki article: Fire door (written by Kimi Code CLI)

← Older revision		Revision as of 05:24, 2 November 2026
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	* [[Fire resistance criteria]]		* [[Fire resistance criteria]]
	* [[Fire-resistant glazing]]		* [[Fire-resistant glazing]]
	* [[~~Means of escape~~]]		* [[Stair pressurisation]]

	== Notes ==		== Notes ==

Jan: New FSE wiki article: Fire door (written by Kimi Code CLI)

2026-11-02T00:55:52Z

New FSE wiki article: Fire door (written by Kimi Code CLI)

New page

A '''Fire door''' is a doorset with a specific fire resistance rating that forms part of a fire separation and, in certain situations, also provides smoke-control capability. It protects an opening in a fire-resistive wall and, if not already closed, closes automatically and latches when required. The complete assembly includes the door leaves, frame, seals, hardware and closing mechanism.<ref name="CVM2-64">Ministry of Business, Innovation and Employment (2025), p. 64.</ref><ref name="NUREG-1805-C-9">U.S. Nuclear Regulatory Commission (2005), p. C-9.</ref>

The door allows normal passage while preserving the separation during fire. Its rating and operation therefore depend on the complete installed assembly and on whether it actually closes in the scenario. A door leaf alone does not demonstrate performance of the opening.<ref name="CVM2-64" /><ref name="CVM2-14">Ministry of Business, Innovation and Employment (2025), p. 14.</ref>

Fire doors are not identical to smoke control doors. Fire doors with smoke-control capability must satisfy both sets of requirements in C/VM2, while smoke control doors have a specific smoke-control function and need not provide the same fire-resistance rating. The intended duty must be identified.<ref name="CVM2-64" /><ref name="NUREG-1805-F-19">U.S. Nuclear Regulatory Commission (2005), p. F-19.</ref>

== Role in compartmentation ==

[[Fire compartmentation]] depends on complete boundaries, and doors create openings that must operate for occupants. A fire door restores that boundary after passage and limits fire and smoke spread for the rated period. Its condition during the entire evacuation sequence matters, not only its normal appearance.<ref name="IFEG-1.6-7">Australian Building Codes Board et al. (2005), p. 1.6-7.</ref><ref name="CVM2-14" />

[[Fire resistance criteria]] apply to the doorset's fire-resistance rating and to the surrounding assembly. The rating should be compatible with the wall and the required function of the opening. Frame, hardware, seals and installation all influence whether the door meets that criterion.<ref name="CVM2-64" /><ref name="NUREG-1805-C-9" />

A fire door can also limit temperature transmission and flame passage, but conduction through the door and wall can still expose the other side. Insulation and integrity therefore need to be evaluated separately from the door merely remaining in its frame.<ref name="IFEG-1.6-7" /><ref name="Rockett-Milke-1-29">Rockett and Milke (2002), p. 1-29.</ref>

The door is part of a wider passive-protection system. It does not suppress the fire or remove the need for detection and response, but it can provide time for evacuation and intervention. A closed fire door should not be credited with reducing heat release unless the scenario supports that effect.<ref name="NUREG-1805-F-44">U.S. Nuclear Regulatory Commission (2005), p. F-44.</ref><ref name="Grant-4-152">Grant (2002), p. 4-152.</ref>

== Intumescent seals and glazing ==

[[Intumescent material]] can expand during heating and help close gaps around the door or frame. This can improve the seal and reduce heat transfer, but its continuity, adhesion and compatibility with door movement determine performance. A damaged or misplaced seal can create a leakage path.<ref name="Beyler-Hirschler-1-110">Beyler and Hirschler (2002), p. 1-110.</ref><ref name="CVM2-13">Ministry of Business, Innovation and Employment (2025), p. 13.</ref>

Seals must allow the door to close and latch correctly. An oversized or degraded seal can obstruct movement, while an insufficient seal can allow smoke and hot gases through. Inspection should include both closing function and the seal's fire condition.<ref name="CVM2-14" /><ref name="Beyler-Hirschler-1-110" />

[[Fire-resistant glazing]] provides a specified fire resistance rating for fixed or openable glazed elements, including frames and fixings. It is evaluated as an assembly, not just as the glass material. Any door vision panel or adjacent glazed element must match the required rating and installation.<ref name="CVM2-64" />

Glazing can also fail earlier than the surrounding door or wall, creating a new path for flame and smoke. C/VM2 treats some smoke separations as remaining only until a rated temperature or flashover, and simpler non-rated construction until an average upper-layer temperature of 200 °C. These are model-specific assumptions, not universal breakage criteria.<ref name="CVM2-14" />

== Smoke movement and escape ==

[[Smoke movement]] through a doorway depends on whether the door is open, its leakage and the pressure difference across it. A closed door restricts that path, but an open door can allow substantial smoke transport. The door's state during evacuation therefore changes tenability on both sides.<ref name="VR-6.6">Van Rossum (2027), §6.6.</ref><ref name="IFEG-2.5-6">Australian Building Codes Board et al. (2005), p. 2.5-6.</ref>

[[Means of escape]] requires occupants to be able to open and pass through the door safely. Self-closing action must not prevent evacuation, and the opening must remain available for the required flow. Fire protection and escape function should be assessed together rather than treated as competing labels.<ref name="CVM2-14" /><ref name="Purser-2-85">Purser (2002), pp. 2-85–2-86.</ref>

C/VM2 assumes self-closing fire and smoke control doors are closed except when being used. At low occupant load it allows three seconds per occupant, while expected queuing keeps the door open for the queue duration. This creates a time-dependent boundary rather than a permanently closed one.<ref name="CVM2-14" />

For bedrooms in care settings, smoke control doors without self-closers are considered closed once evacuation from the bedroom is complete. This is a specific modelling rule in C/VM2 and should not be applied to every occupancy. It illustrates how door state is linked to the evacuation scenario.<ref name="CVM2-14" />

== Operation and hardware ==

A fire door must close automatically and self-latch if it is not already closed. Electromagnetic holders can keep it open during normal use and release after a fire signal, while a self-closer returns it to the closed position. Correct operation includes both movement and final latching.<ref name="CVM2-64" /><ref name="NUREG-1805-F-7">U.S. Nuclear Regulatory Commission (2005), p. F-7.</ref>

Door hardware must withstand the expected use and incident conditions. Hinges, locks, closers and latches can affect whether the door closes fully and remains closed against pressure. A door that swings closed but fails to latch may leave a significant opening.<ref name="CVM2-14" /><ref name="NUREG-1805-C-9" />

Fusible links provide another release mechanism in some assemblies, melting at a predetermined temperature. They should be suitable for the application and should not be obstructed or replaced with an incompatible component. The activation mechanism belongs in the reliability assessment.<ref name="NUREG-1805-F-32">U.S. Nuclear Regulatory Commission (2005), p. F-32.</ref>

Normal operation can be changed by occupants, maintenance or refurbishment. A door wedged open cannot provide the intended barrier, and an altered frame or hold-open device can prevent closure. The actual installed and maintained condition must be established.<ref name="CVM2-13">Ministry of Business, Innovation and Employment (2025), p. 13.</ref><ref name="CVM2-14" />

== Fire-resistance testing ==

The [[Fire resistance test]] for door assemblies evaluates endurance under specified exposure and performance criteria. NFPA 252 includes cellulosic-fire rating periods from 20 minutes to 180 minutes and higher hourly increments in the NUREG-1805 summary. These periods belong to that test method and do not guarantee performance in every installation.<ref name="NUREG-1805-C-9" />

For most ratings, the door assembly is then subjected to impact, erosion and cooling from a hose stream. This tests performance after the fire-endurance period and shows that evaluation includes more than temperature exposure alone. The 20-minute assembly is an exception for which this step is optional in the cited summary.<ref name="NUREG-1805-C-9" />

NUREG-1805 also lists temperature increases of 121 °C, 232 °C and 343 °C, with no temperature rating indicating an increase above 343 °C on the unexposed surface after 30 minutes. These are source-specific test criteria and should not be used as universal door-safety temperatures.<ref name="NUREG-1805-C-9" />

C/VM2 requires fire-rated closures to be tested in accordance with an internationally recognised standard to confirm the rating. It also requires construction detailing to match the design and appropriate proprietary products for orientation and use. This ties product evidence to the installed assembly.<ref name="CVM2-13" />

== Reliability and maintenance ==

Inspection should confirm that the door closes and latches, that seals are continuous and that the frame and hardware remain suitable. Damage, paint, obstruction, wedges and altered hold-open devices can all defeat the intended function. Maintenance must address operation as well as material condition.<ref name="CVM2-14" /><ref name="CVM2-13" />

The surrounding wall and penetration must also remain compatible. A door installed in an altered or weaker partition may not achieve the intended separation, and a repaired frame can change leakage and closing geometry. Review should include the whole assembly rather than the door leaf alone.<ref name="CVM2-64" /><ref name="CVM2-13" />

Fire-door reliability is scenario-dependent. A door can work during a routine test but fail when occupants hold it open, when a queue forms or when a hold-open device does not release. The evacuation and detection sequence should therefore be represented in the assessment.<ref name="CVM2-14" /><ref name="Purser-2-85" />

Any replacement should preserve the rated assembly. Substituting a leaf, closer, seal or latch with an incompatible part can change performance, even if the door still looks similar. Product specifications and installation requirements must be checked before accepting the modification.<ref name="CVM2-13" /><ref name="NUREG-1805-C-9" />

== Limits and common misunderstandings ==

A fire door is not simply a door made from noncombustible material. It is a rated doorset whose performance depends on the complete assembly and its operation. Noncombustibility alone does not establish integrity, insulation or self-closing performance.<ref name="CVM2-64" /><ref name="Kodur-Harmathy-1-155">Kodur and Harmathy (2002), p. 1-155.</ref>

A closed door is not a guaranteed smoke or fire barrier in every situation. Leakage, frame gaps, open periods and failed components can create paths, and other penetrations can bypass the door. The complete compartment boundary must be assessed.<ref name="IFEG-1.6-7" /><ref name="CVM2-14" />

A fire door is also not the same as a smoke control door. Smoke control capability has its own requirements, and fire doors with that capability must satisfy both. Using one label for every door can hide missing fire-resistance or smoke-control criteria.<ref name="CVM2-64" /><ref name="NUREG-1805-F-19" />

Finally, a fire door does not replace suppression or safe escape design. It supports compartmentation and can provide time for response, but occupants still need usable exits and the fire still requires appropriate detection and control. Those functions must be coordinated.<ref name="IFEG-1.6-3">Australian Building Codes Board et al. (2005), p. 1.6-3.</ref><ref name="Grant-4-152" />

== Assessment and review ==

A door assessment should follow the entire opening and closing sequence. It should establish who uses the door, how long it remains open and whether it then closes and latches. This connects the fire-resistance rating with the actual evacuation and firefighting scenario.<ref name="CVM2-14" /><ref name="IFEG-1.6-3">Australian Building Codes Board et al. (2005), p. 1.6-3.</ref>

For low occupant loads, C/VM2 uses a three-second opening per occupant, while expected queues keep the door open continuously. Those assumptions affect the duration and direction of smoke flow. The assessment should state which applies and should not replace them with an assumed permanently closed door.<ref name="CVM2-14" />

For escape, the door must remain usable without trapping occupants or preventing the required flow. Self-closing and latching functions must be compatible with passage, accessibility and the exit strategy. A door that protects only after everyone has left can still be useful, but the analysis must account for the period of use.<ref name="CVM2-14" /><ref name="Purser-2-85" />

The complete assembly should be compared with the test evidence. Leaves, frame, seals, hinges, closer and latch all affect performance, and substituting one can change the result. A rating for a doorset should not be assigned to an individual leaf or an incompatible frame.<ref name="NUREG-1805-C-9" /><ref name="CVM2-13" />

Glazed elements require separate attention because they can fail before the rest of the doorset. Frames and fixings are part of their rating, and the model may treat smoke separations as lost after a selected temperature or flashover. The assessment should not assume that glazing remains intact by default.<ref name="CVM2-64" /><ref name="CVM2-14" />

Intumescent seals should be checked for movement as well as fire response. They must expand without preventing closure and must remain continuous under the expected deformation. A seal that is intact during a static inspection can still fail when the door is used or the frame moves.<ref name="Beyler-Hirschler-1-110" /><ref name="CVM2-13" />

For maintenance, the actual installed and operating condition should be demonstrated. Wedges, damage, paint, altered hold-open devices and incomplete repairs can all prevent closure or sealing. Any change should be reviewed against the rated assembly rather than accepting a visually similar replacement.<ref name="CVM2-13" /><ref name="NUREG-1805-C-9" />

A final review should state which functions were evaluated: fire resistance, smoke control, escape and normal use. Satisfying one does not prove the others, and a fire door with smoke-control capability must meet both relevant requirement sets. This keeps the doorset's role clear within compartmentation and evacuation.<ref name="CVM2-64" /><ref name="Purser-2-85" />

The door's rating should not be separated from its operation in the incident. A closed doorset can satisfy a furnace test but fail to protect if it is wedged open, held by a queue or unable to latch. The assessment must therefore include occupancy, maintenance and the actual opening history.<ref name="CVM2-14" /><ref name="CVM2-13" />

Evidence should also be assigned to the complete doorset rather than to a material or component. A fire-resistant leaf cannot compensate for an unsuitable frame, seal or closer, and a smoke-control function cannot be inferred from the door's presence alone. All relevant criteria must be demonstrated.<ref name="NUREG-1805-C-9" /><ref name="CVM2-64" />

For final acceptance, the report should link the tested assembly, installation, opening sequence and acceptance criteria. This shows whether fire resistance, smoke control and safe escape are achieved together or whether one remains unresolved. That integrated view is the practical meaning of a fire door in compartmentation.<ref name="CVM2-64" /><ref name="IFEG-1.6-3" />

The assessment should also state which criteria were verified for the actual opening. A fire-resistance rating, a smoke-leakage requirement and an escape requirement measure different things, and one cannot be inferred from the others. The doorset must satisfy each applicable criterion in its installed condition.<ref name="CVM2-64" /><ref name="Purser-2-85" />

For final acceptance, the tested assembly, installation and incident sequence should remain linked. A door that closes and latches correctly but is held open by occupants or damaged by use cannot provide the expected separation. Maintaining those operational conditions is part of achieving the fire door's rated performance.<ref name="CVM2-14" /><ref name="CVM2-13" />

== See also ==

* [[Fire resistance criteria]]
* [[Fire-resistant glazing]]
* [[Means of escape]]

== Notes ==

<references />

== References ==

* Australian Building Codes Board, National Research Council of Canada, International Code Council, & Department of Building and Housing New Zealand. (2005). ''International fire engineering guidelines'' (2005 ed.). Australian Building Codes Board.
* Beyler, C. L., & Hirschler, M. M. (2002). Thermal decomposition of polymers. In P. J. DiNenno (Ed.), ''SFPE handbook of fire protection engineering'' (3rd ed.). National Fire Protection Association.
* Grant, C. C. (2002). Halon design calculations. In P. J. DiNenno (Ed.), ''SFPE handbook of fire protection engineering'' (3rd ed.). National Fire Protection Association.
* Kodur, V. K. R., & Harmathy, T. Z. (2002). Properties of building materials. In P. J. DiNenno (Ed.), ''SFPE handbook of fire protection engineering'' (3rd ed.). National Fire Protection Association.
* Ministry of Business, Innovation and Employment. (2025). ''C protection from fire: Verification method C/VM2'' (2nd ed.). New Zealand Government.
* Purser, D. A. (2002). Toxicity assessment of combustion products. In P. J. DiNenno (Ed.), ''SFPE handbook of fire protection engineering'' (3rd ed.). National Fire Protection Association.
* Rockett, J. A., & Milke, J. A. (2002). Conduction of heat in solids. In P. J. DiNenno (Ed.), ''SFPE handbook of fire protection engineering'' (3rd ed.). National Fire Protection Association.
* U.S. Nuclear Regulatory Commission. (2005). ''Fire dynamics tools: Quantitative fire hazard analysis methods for the U.S. nuclear regulatory commission fire protection inspection program'' (NUREG-1805). Author.
* Van Rossum, E. (2027). ''Introduction to Fire Safety Engineering''. Fire Safety Academy.

[[Category:Passive Fire Protection]]

← Older revision		Revision as of 19:42, 2 November 2026
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	A '''fire door''' is a rated doorset that protects an opening in a fire separation. It allows access through the boundary while providing specified resistance when closed. The thermal and integrity functions concern the complete construction, while closing and latching establish the operating state on which that performance depends.<ref name="KH_1-155">Kodur and Harmathy (2002), p. 1-155.</ref><ref name="CVM_64">Ministry of Business, Innovation and Employment (2025), p. 64.</ref>		A '''fire door''' is a rated doorset that protects an opening in a fire separation. It allows access through the boundary while providing specified resistance when closed. The thermal and integrity functions concern the complete construction, while closing and latching establish the operating state on which that performance depends.<ref name="KH_1-155">Kodur and Harmathy (2002), p. 1-155.</ref><ref name="CVM_64">Ministry of Business, Innovation and Employment (2025), p. 64.</ref>

	A door is consequently more than its leaf material~~. Its~~ installation, associated components and evidence of assembly performance matter to the claimed rating. Smoke control may require additional performance beyond the fire-resistance function. New Zealand's C/VM2, second edition of 2025, distinguishes those requirements explicitly.<ref name="CVM_13">Ministry of Business, Innovation and Employment (2025), p. 13.</ref><ref name="CVM_15">Ministry of Business, Innovation and Employment (2025), p. 15.</ref><ref name="CVM_64" />		A door is consequently more than its leaf material: its installation, associated components and evidence of assembly performance matter to the claimed rating. Smoke control may require additional performance beyond the fire-resistance function. New Zealand's C/VM2, second edition of 2025, distinguishes those requirements explicitly.<ref name="CVM_13">Ministry of Business, Innovation and Employment (2025), p. 13.</ref><ref name="CVM_15">Ministry of Business, Innovation and Employment (2025), p. 15.</ref><ref name="CVM_64" />

	A fire door also forms a changing part of [[Fire compartmentation]]. Occupants open it during evacuation, while pressure differences can move smoke through gaps or the open doorway. Understanding its role therefore requires both the closed-state evidence and the conditions under which it opens and closes during the event.<ref name="IFEG_1.6-7">Australian Building Codes Board et al. (2005), p. 1.6-7.</ref><ref name="Kl_4-277_4-279">Klote (2002), pp. 4-277–4-279.</ref>		A fire door also forms a changing part of [[Fire compartmentation]]. Occupants open it during evacuation, while pressure differences can move smoke through gaps or the open doorway. Understanding its role therefore requires both the closed-state evidence and the conditions under which it opens and closes during the event.<ref name="IFEG_1.6-7">Australian Building Codes Board et al. (2005), p. 1.6-7.</ref><ref name="Kl_4-277_4-279">Klote (2002), pp. 4-277–4-279.</ref>
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	[[File:fse-fire-door-v1.svg\|thumb\|upright=1.5\|alt=Fire door with labelled leaf, frame, intumescent seal, closer and latch in a fire separation.\|A fire door is a complete doorset, not only a leaf. Based on Ministry of Business, Innovation and Employment (2025), p. 64 and Iqbal and Salley (2004), p. C-10.]]		[[File:fse-fire-door-v1.svg\|thumb\|upright=1.5\|alt=Fire door with labelled leaf, frame, intumescent seal, closer and latch in a fire separation.\|A fire door is a complete doorset, not only a leaf. Based on Ministry of Business, Innovation and Employment (2025), p. 64 and Iqbal and Salley (2004), p. C-10.]]

	An [[Intumescent material]] swells during heating and can change the thermal path through an assembly. Van Rossum describes that general protective mechanism without defining the performance of a particular doorset~~. Its~~ presence does not replace evidence for the complete door. The construction, operation and claimed fire performance remain separate parts of the assessment.<ref name="VR_5.2">Van Rossum (2027), §5.2.</ref><ref name="CVM_13" />		An [[Intumescent material]] swells during heating and can change the thermal path through an assembly. Van Rossum describes that general protective mechanism without defining the performance of a particular doorset; its presence does not replace evidence for the complete door. The construction, operation and claimed fire performance remain separate parts of the assessment.<ref name="VR_5.2">Van Rossum (2027), §5.2.</ref><ref name="CVM_13" />

	[[Fire-resistant glazing]] likewise concerns a complete assembly rather than glass alone. C/VM2's definition includes the glazing, frame, fixings and associated components~~. The~~ source therefore distinguishes a rated glazing arrangement from an unspecified glazed opening. A glazed door requires evidence relevant to the assembled construction in which that glazing is used.<ref name="CVM_64" /><ref name="CVM_13" />		[[Fire-resistant glazing]] likewise concerns a complete assembly rather than glass alone. C/VM2's definition includes the glazing, frame, fixings and associated components, and the source therefore distinguishes a rated glazing arrangement from an unspecified glazed opening. A glazed door requires evidence relevant to the assembled construction in which that glazing is used.<ref name="CVM_64" /><ref name="CVM_13" />

	== Fire resistance and smoke performance ==		== Fire resistance and smoke performance ==

	[[Fire resistance criteria]] identify the functions evaluated under the prescribed exposure. Integrity addresses the passage of flames or hot gases, while insulation addresses heat transmission~~. A~~ separating element may require different evidence for these outcomes. Neither can be inferred solely from the appearance or combustibility of the door material.<ref name="KH_1-155" /><ref name="M_4-210_4-211">Milke (2002), pp. 4-210–4-211.</ref>		[[Fire resistance criteria]] identify the functions evaluated under the prescribed exposure. Integrity addresses the passage of flames or hot gases, while insulation addresses heat transmission; a separating element may require different evidence for these outcomes. Neither can be inferred solely from the appearance or combustibility of the door material.<ref name="KH_1-155" /><ref name="M_4-210_4-211">Milke (2002), pp. 4-210–4-211.</ref>

	[[Smoke movement]] introduces leakage paths and pressure differences. Klote identifies cracks around closed doors as paths through which gases can move~~. A~~ closed leaf ~~therefore~~ does not imply an airtight boundary. The amount and direction of movement depend on both the available path and the forces acting across it.<ref name="Kl_4-277_4-278">Klote (2002), pp. 4-277–4-278.</ref>		[[Smoke movement]] introduces leakage paths and pressure differences. Klote identifies cracks around closed doors as paths through which gases can move, so a closed leaf does not imply an airtight boundary. The amount and direction of movement depend on both the available path and the forces acting across it.<ref name="Kl_4-277_4-278">Klote (2002), pp. 4-277–4-278.</ref>

	New Zealand's 2025 C/VM2 explicitly separates fire-door and smoke-control-door provisions. A fire door with smoke-control capability must satisfy both sets of provisions identified by that method~~. This~~ distinction prevents a fire rating from being read as a complete smoke-leakage specification. It also identifies which function is being credited in the analysis.<ref name="CVM_15" />		New Zealand's 2025 C/VM2 explicitly separates fire-door and smoke-control-door provisions. A fire door with smoke-control capability must satisfy both sets of provisions identified by that method; this distinction prevents a fire rating from being read as a complete smoke-leakage specification. It also identifies which function is being credited in the analysis.<ref name="CVM_15" />

	A smoke separation need not have the same fire-resisting capability as a fire separation. C/VM2 applies different assumptions to their continued presence as conditions become more severe~~. Its~~ discussion explains why a boundary credited early in a fire may not be credited after flashover. That is a modelling distinction, not a universal physical failure temperature for every door.<ref name="CVM_14_15">Ministry of Business, Innovation and Employment (2025), pp. 14–15.</ref>		A smoke separation need not have the same fire-resisting capability as a fire separation. C/VM2 applies different assumptions to their continued presence as conditions become more severe, and its discussion explains why a boundary credited early in a fire may not be credited after flashover. That is a modelling distinction, not a universal physical failure temperature for every door.<ref name="CVM_14_15">Ministry of Business, Innovation and Employment (2025), pp. 14–15.</ref>

	== Testing and interpretation of ratings ==		== Testing and interpretation of ratings ==

	A [[Fire resistance test]] places the doorset under a defined exposure and evaluates specified endpoints. The 2004 NUREG-1805 report summarises United States NFPA 252 door-assembly testing~~. It~~ describes tests continuing to the selected rating period or an earlier performance failure. The report is a historical technical summary, not the full standard or a current product approval.<ref name="N_C-10" />		A [[Fire resistance test]] places the doorset under a defined exposure and evaluates specified endpoints. The 2004 NUREG-1805 report summarises United States NFPA 252 door-assembly testing, and it describes tests continuing to the selected rating period or an earlier performance failure. The report is a historical technical summary, not the full standard or a current product approval.<ref name="N_C-10" />

	The summary includes rated periods such as 20, 30, 45, 60, 90 and 180 minutes~~. These~~ durations belong to the reported test framework. They do not establish a universal duration required for every door or every location. The required performance follows the building context and the applicable classification and design provisions.<ref name="N_C-10" /><ref name="CVM_13" />		The summary includes rated periods such as 20, 30, 45, 60, 90 and 180 minutes; these durations belong to the reported test framework. They do not establish a universal duration required for every door or every location. The required performance follows the building context and the applicable classification and design provisions.<ref name="N_C-10" /><ref name="CVM_13" />

	The same summary describes a hose-stream exposure following the fire-endurance test~~. Its~~ purpose is to apply impact, erosion and cooling to the heated assembly. The report identifies an exception in which the hose stream is optional for the stated 20-minute-rated assemblies. It is therefore inaccurate to describe this stage as mandatory for every door test worldwide.<ref name="N_C-10" />		The same summary describes a hose-stream exposure following the fire-endurance test, and its purpose is to apply impact, erosion and cooling to the heated assembly. The report identifies an exception in which the hose stream is optional for the stated 20-minute-rated assemblies. It is therefore inaccurate to describe this stage as mandatory for every door test worldwide.<ref name="N_C-10" />

	[[File:fse-fire-door-v3.svg\|thumb\|upright=1.5\|alt=Door in furnace followed by hose-stream impact, erosion and cooling.\|Fire-door testing includes endurance and hose-stream response. Based on Iqbal and Salley (2004), p. C-10.]]		[[File:fse-fire-door-v3.svg\|thumb\|upright=1.5\|alt=Door in furnace followed by hose-stream impact, erosion and cooling.\|Fire-door testing includes endurance and hose-stream response. Based on Iqbal and Salley (2004), p. C-10.]]

	Test evidence also retains its construction context. New Zealand's 2025 verification method requires details during construction to match the developed design~~. Its~~ commentary connects rated closures to testing under an internationally recognised standard. This links the installed doorset to its evidence instead of assigning a rating from its thickness or material name alone.<ref name="CVM_13" />		Test evidence also retains its construction context. New Zealand's 2025 verification method requires details during construction to match the developed design; its commentary connects rated closures to testing under an internationally recognised standard. This links the installed doorset to its evidence instead of assigning a rating from its thickness or material name alone.<ref name="CVM_13" />

	== Door use during evacuation ==		== Door use during evacuation ==

	A door protecting [[Means of escape]] must be considered in both its closed and open states. When occupants pass through, they temporarily change the separating boundary~~. The~~ International Fire Engineering Guidelines therefore obtain opening times from the evacuation analysis. A closed-door furnace result does not describe those periods of use.<ref name="IFEG_1.6-7" />		A door protecting [[Means of escape]] must be considered in both its closed and open states. When occupants pass through, they temporarily change the separating boundary, and the International Fire Engineering Guidelines therefore obtain opening times from the evacuation analysis. A closed-door furnace result does not describe those periods of use.<ref name="IFEG_1.6-7" />

	C/VM2, second edition of 2025, provides a specific modelling convention for this interaction. Fire and smoke-control doors with self-closers are assumed closed unless occupants are using them. For low occupant demand, the model allows three seconds of opening per occupant. The commentary connects that interval to opening the leaf, passing through and allowing it to close.<ref name="CVM_15" />		C/VM2, second edition of 2025, provides a specific modelling convention for this interaction. Fire and smoke-control doors with self-closers are assumed closed unless occupants are using them. For low occupant demand, the model allows three seconds of opening per occupant. The commentary connects that interval to opening the leaf, passing through and allowing it to close.<ref name="CVM_15" />
Line 49:		Line 49:
	[[File:fse-fire-door-v2.svg\|thumb\|upright=1.5\|alt=Door opens for three seconds per occupant and remains open during a queue before closing.\|Fire-door state changes during evacuation. Based on Ministry of Business, Innovation and Employment (2025), p. 15.]]		[[File:fse-fire-door-v2.svg\|thumb\|upright=1.5\|alt=Door opens for three seconds per occupant and remains open during a queue before closing.\|Fire-door state changes during evacuation. Based on Ministry of Business, Innovation and Employment (2025), p. 15.]]

	For smoke-flow calculations during egress, C/VM2 represents the open door using half its width. The commentary explains that the moving leaf and occupants obstruct part of the opening~~. This~~ is an effective opening assumption for that analysis. It does not redefine the constructed door width or the width available under separate escape provisions.<ref name="CVM_15_16">Ministry of Business, Innovation and Employment (2025), pp. 15–16.</ref>		For smoke-flow calculations during egress, C/VM2 represents the open door using half its width. The commentary explains that the moving leaf and occupants obstruct part of the opening; this is an effective opening assumption for that analysis. It does not redefine the constructed door width or the width available under separate escape provisions.<ref name="CVM_15_16">Ministry of Business, Innovation and Employment (2025), pp. 15–16.</ref>

	== Pressure differences and open doorways ==		== Pressure differences and open doorways ==
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	A closed door and an open doorway present different airflow problems. With a closed door, the paths may consist mainly of small gaps. With an open door, a much larger passage connects the spaces. Klote distinguishes pressure control across mostly closed barriers from airflow control through large openings.<ref name="Kl_4-278_4-279">Klote (2002), pp. 4-278–4-279.</ref>		A closed door and an open doorway present different airflow problems. With a closed door, the paths may consist mainly of small gaps. With an open door, a much larger passage connects the spaces. Klote distinguishes pressure control across mostly closed barriers from airflow control through large openings.<ref name="Kl_4-278_4-279">Klote (2002), pp. 4-278–4-279.</ref>

	Mechanical pressurisation can oppose smoke entry through leakage paths~~. Its~~ intended airflow is from the protected side towards the smoke-exposed side. When a door opens, however, low air velocity may permit smoke to flow back through part of the opening. The closed-door pressure condition does not by itself establish the open-door performance.<ref name="Kl_4-278">Klote (2002), p. 4-278.</ref>		Mechanical pressurisation can oppose smoke entry through leakage paths, and its intended airflow is from the protected side towards the smoke-exposed side. When a door opens, however, low air velocity may permit smoke to flow back through part of the opening. The closed-door pressure condition does not by itself establish the open-door performance.<ref name="Kl_4-278">Klote (2002), p. 4-278.</ref>

	The forces moving smoke can also come from outside the mechanical system. Buoyancy, stack effect and wind affect the pressure field within a building. Klote explains that fan shutdown alone does not stop movement through all available paths. A door's leakage and operating state therefore interact with the surrounding building conditions.<ref name="Kl_4-274">Klote (2002), p. 4-274.</ref><ref name="Kl_4-277">Klote (2002), p. 4-277.</ref>		The forces moving smoke can also come from outside the mechanical system. Buoyancy, stack effect and wind affect the pressure field within a building. Klote explains that fan shutdown alone does not stop movement through all available paths. A door's leakage and operating state therefore interact with the surrounding building conditions.<ref name="Kl_4-274">Klote (2002), p. 4-274.</ref><ref name="Kl_4-277">Klote (2002), p. 4-277.</ref>