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HKIE Professional Assessment - Fire Discipline study materials
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HKIE Professional Assessment - Fire Discipline practice questions

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Question 1Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

In a compartment fire, which stage is characterised by the simultaneous ignition of all combustible surfaces and a rapid rise in temperature to several hundred degrees Celsius?

  1. Backdraught
  2. Decay
  3. Flashover Correct answer.
  4. Smouldering

Explanation

Flashover marks the transition from a growth-stage fire to a fully developed fire, driven by the feedback of thermal radiation from the hot smoke layer onto the fuel surfaces. The upper layer reaches the order of 500 to 600 degrees Celsius and heat flux at floor level typically exceeds about 20 kW/m2, causing simultaneous ignition of all exposed combustibles.

Question 2Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

Which of the following best describes the fire triangle as applied to flaming combustion?

  1. Fuel, nitrogen, and a catalyst acting together
  2. Heat, pressure, and humidity acting together
  3. Fuel, oxidiser, and an ignition source acting together Correct answer.
  4. Fuel, inert gas, and a heat sink acting together

Explanation

Flaming combustion requires fuel, an oxidiser (normally oxygen from air) and an ignition energy source to be present together; removing any one leg stops flaming. The fourth element of the fire tetrahedron, the chemical chain reaction, is what dry chemical agents interrupt.

Question 3Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

A fire in a sealed room is burning steadily and the oxygen concentration falls below about 10 percent. What is the most likely consequence?

  1. The heat release rate becomes fuel-controlled and rises steadily
  2. The fire transitions immediately to flashover
  3. The heat release rate becomes ventilation-controlled and flaming may cease Correct answer.
  4. The neutral plane rises to the ceiling and smoke production stops

Explanation

When oxygen falls to roughly 10 percent or below, flaming combustion in a compartment cannot be sustained and the fire becomes ventilation-controlled, producing unburnt fuel-rich gases. These gases create the backdraught hazard when air is later admitted.

Question 4Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

Which mode of heat transfer is dominant in preheating remote fuel surfaces ahead of a growing compartment fire?

  1. Latent heat release from condensing smoke
  2. Thermal radiation from the hot smoke layer Correct answer.
  3. Convection through the solid compartment walls
  4. Conduction through the compartment floor

Explanation

In the growth stage the smoke layer forms a hot radiating plane, and radiation from that layer and the flame is the principal mechanism preheating distant fuel packages. Radiation intensity scales with the fourth power of absolute temperature, so a thickening hot layer rapidly accelerates spread.

Question 5Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

Which quantity expresses the rate at which energy is released by a burning material and is the primary input to most compartment fire models?

  1. Thermal inertia
  2. Specific heat capacity
  3. Lower calorific value
  4. Heat release rate Correct answer.

Explanation

The heat release rate, usually in kilowatts or megawatts, is the energy released per unit time and is the main driver in fire models such as zone and field models. It is measured by oxygen consumption calorimetry, where roughly 13.1 MJ of heat is released per kilogram of oxygen consumed.

Question 6Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

Smoke is rising through a tall atrium with no sprinkler activation. Which statement about smoke movement is most accurate?

  1. Buoyancy drives the smoke upward and it accumulates first at the highest level Correct answer.
  2. Smoke movement is governed solely by wind pressure on the facade
  3. Smoke spreads only by diffusion and remains near the fire origin
  4. Smoke descends to floor level immediately because it is denser than air

Explanation

Hot smoke from a fire is buoyant relative to cool ambient air and forms a rising plume that mushrooms beneath the ceiling and accumulates at the highest level. In tall spaces this produces a descending smoke layer once the reservoir fills, which is the basis for smoke reservoir and natural venting design.

Question 7Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

What does the term 'neutral plane' describe at an opening in a compartment fire?

  1. The level at which combustion becomes stoichiometric
  2. The level at which radiation heat flux falls to zero
  3. The horizontal level where the pressure inside equals the pressure outside Correct answer.
  4. The level at which the smoke temperature equals ambient temperature

Explanation

At a compartment opening, hot gases flow out above the neutral plane and cool air flows in below it because the pressure difference reverses sign at that height. The neutral plane position shifts with fire size, ventilation and wind, and is a key indicator for firefighters.

Question 8Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

Which fuel property most directly governs how quickly a solid combustible reaches sustained flaming ignition when exposed to a constant radiant flux?

  1. Lower calorific value of the fuel
  2. Time to ignition under that flux Correct answer.
  3. Smoke yield of the fuel
  4. Total mass of the fuel package

Explanation

Time to ignition at a given irradiance integrates the surface heating and pyrolysis needed to produce a flammable vapour mixture, so it is the property used in fire growth and spread modelling. It depends on thermal inertia, ignition temperature and critical heat flux.

Question 9Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

A compartment has a single door opening of area 1.6 m2 and height 1.9 m. Using the ventilation factor A times the square root of H, what is the value in m to the power 2.5?

  1. Approximately 3.0
  2. Approximately 1.6
  3. Approximately 4.1
  4. Approximately 2.2 Correct answer.

Explanation

The ventilation factor is A multiplied by the square root of H. The square root of 1.9 is about 1.38, and 1.6 multiplied by 1.38 gives approximately 2.2 m to the power 2.5. This factor appears in classical correlations for ventilation-controlled burning rate.

Question 10Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

According to the classical correlation for ventilation-controlled burning, the mass burning rate is proportional to which expression?

  1. A plus H
  2. A divided by H
  3. A times H squared
  4. A times the square root of H Correct answer.

Explanation

For a ventilation-limited compartment fire the fuel mass loss rate is approximately 0.09 times A times the square root of H in kilograms per second, where A is opening area and H is opening height. The square-root dependence arises from the buoyancy-driven flow through the opening.

Question 11Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

In a two-zone compartment model, which assumption is fundamental?

  1. The upper layer is well mixed at one temperature and the lower layer is at ambient Correct answer.
  2. Smoke production is ignored below the ceiling
  3. The whole compartment is at a single uniform temperature
  4. The fire is always fuel-controlled throughout

Explanation

Zone models divide the compartment into a hot upper layer and a cooler lower layer, each treated as homogeneous in temperature and composition, with mass and energy exchanged across the interface and at openings. This simplification makes them fast enough for engineering design compared with field models.

Question 12Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

A field model such as CFD is preferred over a zone model in which situation?

  1. Establishing a design fire heat release rate from a code table
  2. Estimating bulk upper-layer temperature in a single rectangular room
  3. Checking a simple hand calculation of ventilation factor
  4. Predicting smoke movement in a large complex geometry with atria and multiple levels Correct answer.

Explanation

Field models solve the conservation equations on a fine grid and resolve local flow features, which is necessary in complex geometries where zone models cannot capture channelling, stratification and multi-level smoke spread. The cost is much greater computation and expertise.

Question 13Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

A fire in a room with a closed door but a partly open high-level window continues to burn. Which hazard is most associated with later opening the door?

  1. Reduction of the fire to a smouldering state
  2. Spontaneous ignition of the smoke layer
  3. Backdraught from sudden air ingress into a fuel-rich compartment Correct answer.
  4. Flashover caused by loss of fuel

Explanation

An oxygen-starved fire generates large quantities of unburnt pyrolysis products and carbon monoxide that accumulate in the compartment. When air is admitted, the incoming oxygen can mix with this fuel-rich gas and deflagrate, producing a backdraught that can force flame and pressure out of the opening.

Question 14Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

Which statement correctly distinguishes a flashover from a backdraught?

  1. Flashover occurs only in sealed compartments; backdraught occurs only in well-ventilated ones
  2. Flashover produces no pressure rise; backdraught produces no flame
  3. Flashover involves unburnt gas explosion; backdraught involves radiant ignition of all surfaces
  4. Flashover is driven by radiant heat feedback; backdraught is driven by sudden air ingress into accumulated unburnt gases Correct answer.

Explanation

Flashover results from thermal feedback raising all combustible surfaces to ignition, whereas a backdraught is a deflagration of accumulated unburnt gases when oxygen is suddenly introduced. The two have different precursors: high upper-layer temperature for flashover, and a starved fire with dense fuel-rich smoke for backdraught.

Question 15Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

Which of the following is the standard method used to measure heat release rate of a burning material in a furniture calorimeter?

  1. Oxygen consumption calorimetry Correct answer.
  2. Differential scanning calorimetry
  3. Gas chromatography of the smoke
  4. Thermogravimetric analysis

Explanation

Oxygen consumption calorimetry measures the depletion of oxygen in the exhaust duct and uses the Huggett relation, about 13.1 MJ released per kilogram of oxygen consumed, to compute the heat release rate. This is the basis of cone calorimeter and furniture calorimeter testing.

Question 16Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

A growing fire follows a t-squared growth curve with a growth coefficient of 0.047 kW/s2. Approximately what heat release rate is reached 300 seconds after ignition?

  1. About 42 MW
  2. About 0.42 MW
  3. About 4.2 MW Correct answer.
  4. About 0.14 MW

Explanation

For a t-squared fire the heat release rate equals the growth coefficient multiplied by the square of time. Here 0.047 multiplied by 300 squared, which is 90,000, gives approximately 4,230 kW or about 4.2 MW. This corresponds to a fast-growing fire typical of upholstered furniture.

Question 17Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

Which parameter is used to characterise the tendency of a compartment fire to reach flashover, based on upper-layer temperature and heat release rate?

  1. The Reynolds number of the smoke layer
  2. The smoke yield per unit mass
  3. The MQH correlation relating heat release rate, opening height and layer temperature Correct answer.
  4. The stoichiometric ratio of the fuel

Explanation

The McCaffrey, Quintiere and Harkleroad correlation predicts upper-layer temperature from heat release rate, opening area and height, and flashover is commonly associated with an upper-layer temperature around 600 degrees Celsius. It is widely used to judge whether a design fire will lead to flashover.

Question 18Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

In a compartment fire, what does the term 'vitiation' refer to?

  1. The depletion of oxygen and build-up of combustion products in the compartment atmosphere Correct answer.
  2. The ignition of soot in the upper layer
  3. The evaporation of water from sprinkler discharge
  4. The collapse of the compartment structure due to heat

Explanation

Vitiation describes the reduction in oxygen concentration and increase in carbon dioxide and other products in the compartment air, which reduces combustion efficiency and can extinguish flaming. It is a key reason fires become under-ventilated and produce large amounts of carbon monoxide.

Question 19Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

Which statement about the effect of a sprinkler system on fire growth in a compartment is correct?

  1. It controls or suppresses the fire before flashover by cooling the fire plume and wetting fuels Correct answer.
  2. It prevents smoke production entirely once activated
  3. It increases the heat release rate by adding water vapour to the smoke layer
  4. It guarantees structural stability without any other measures

Explanation

Sprinklers operate on the fire plume, cooling the burning fuel and pre-wetting surrounding combustibles, which reduces the heat release rate and prevents the radiant feedback needed for flashover. Smoke is still produced, and design must account for smoke management independently.

Question 20Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

A design fire is described as 'fast' in the t-squared classification. Which growth coefficient in kW/s2 corresponds to this classification?

  1. 0.003
  2. 0.19
  3. 0.012
  4. 0.047 Correct answer.

Explanation

The NFPA t-squared classifications are slow at about 0.003, medium at about 0.012, fast at about 0.047 and ultrafast at about 0.19 kW/s2. These correspond to times to reach 1 MW of roughly 600, 300, 150 and 75 seconds respectively.

Question 21Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

Why does a compartment fire with limited ventilation often produce higher carbon monoxide concentrations than a well-ventilated fire?

  1. Incomplete combustion under oxygen deficiency produces more carbon monoxide per unit fuel burned Correct answer.
  2. Higher temperatures always destroy carbon monoxide
  3. Carbon monoxide is produced only when the fuel is fully oxidised
  4. Water vapour reacts with fuel to form carbon monoxide

Explanation

When oxygen is limited, combustion is incomplete and a larger fraction of the carbon in the fuel is converted to carbon monoxide rather than carbon dioxide. This raises the toxicity of the smoke and is a principal life-safety concern in under-ventilated compartments.

Question 22Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

A fire grows in a compartment with a ceiling height of 3 m. Using the common plume correlation, the smoke layer descent rate depends most strongly on which factor?

  1. The ambient humidity in the compartment
  2. The moisture content of the fuel
  3. The heat release rate of the fire Correct answer.
  4. The colour of the smoke

Explanation

The rate at which the smoke layer descends is governed by the volumetric flow in the fire plume, which scales with the convective heat release rate raised to the one-third power and with the height above the fire. Larger fires fill the compartment with smoke faster.

Question 23Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

In a compartment fire, the phenomenon in which flames rapidly spread across the ceiling away from the seat of the fire is known as what?

  1. Flashover
  2. Backdraught
  3. Smouldering
  4. Ceiling jet flame spread, often called rollover Correct answer.

Explanation

Rollover occurs when the accumulating hot upper layer reaches its ignition temperature and flames sweep across the ceiling, indicating the fire is approaching flashover. It is a warning sign for firefighters that the compartment is heating rapidly.

Question 24Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

Which statement about the influence of opening size on a post-flashover compartment fire is correct?

  1. Opening size has no effect once flashover has occurred
  2. Larger openings reduce the mass loss rate of the fuel
  3. Increasing ventilation increases the burning rate until the fire becomes fuel-controlled Correct answer.
  4. Increasing ventilation always decreases the compartment temperature

Explanation

After flashover the fire is typically ventilation-controlled, so enlarging the opening admits more oxygen and raises the mass burning rate and heat release rate. Once the fuel surface area becomes the limiting factor, the fire becomes fuel-controlled and further ventilation does not increase burning.

Question 25Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

A zone model predicts a hot upper-layer temperature of 620 degrees Celsius in a room with a 2.4 m ceiling. What is the principal engineering implication?

  1. The fire is likely to have reached or be close to flashover conditions Correct answer.
  2. The compartment must be fully ventilated to survive
  3. The smoke layer is too cool to cause radiant ignition
  4. The fire is certainly still in the incipient stage

Explanation

An upper-layer temperature of about 600 degrees Celsius is the widely used flashover criterion because radiant feedback to floor-level fuels then becomes sufficient for ignition. A prediction of 620 degrees Celsius therefore signals likely flashover and drives the choice of fire protection and egress strategy.

Question 26Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

In a compartment fire, which quantity expresses the energy released per unit time and is the parameter most directly used to size smoke control and structural fire protection?

  1. Fire load density
  2. Mass loss rate
  3. Lower calorific value
  4. Heat release rate Correct answer.

Explanation

Heat release rate (HRR, in kW or MW) is the energy released per unit time and is the primary design parameter for smoke control, tenability and structural protection. Fire load density instead describes total potential energy per unit floor area, while mass loss rate and calorific value are inputs used to compute HRR rather than the rate itself.

Question 27Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

A fire in a room grows from ignition and the hot upper smoke layer descends. Which condition is the essential trigger for flashover in a ventilation-limited compartment?

  1. The neutral plane rises above the top of the door opening
  2. The upper layer reaches a critical temperature of roughly 500 to 600 degrees Celsius and radiant heat flux to the floor fuels ignites Correct answer.
  3. The fire becomes fuel-controlled with excess air available
  4. The lower layer oxygen concentration falls below 15 percent

Explanation

Flashover is a transition to full room involvement driven by feedback from the hot upper layer; radiant heat flux to the floor of roughly 20 kW/m2, corresponding to upper-layer temperatures near 500 to 600 degrees Celsius, ignites all combustible surfaces. Oxygen depletion and neutral plane position influence the fire but are not the defining trigger.

Question 28Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

A compartment 5 m by 4 m by 2.5 m high has a single door opening 0.9 m wide and 2.0 m high. Using the ventilation factor A times the square root of H, what is the approximate value in m to the power 2.5?

  1. 1.80
  2. 2.55
  3. 1.27 Correct answer.
  4. 0.90

Explanation

The ventilation factor is A times the square root of H, where A is the opening area and H its height. The opening area is 0.9 times 2.0, equal to 1.8 m2, and the square root of 2.0 is about 1.414, so the factor is approximately 1.8 times 1.414, equal to about 2.55 m to the power 2.5.

Question 29Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

A CFD field model and a zone model are both available for a design analysis. Which situation makes the field model the more appropriate choice?

  1. Estimating the mass burning rate of a ventilation-controlled fire in a single compartment
  2. Producing a quick parametric estimate of time to flashover for a simple office
  3. Estimating the average upper-layer temperature in a single rectangular room with one door
  4. Predicting smoke spread through a large complex atrium with irregular geometry and multiple connected volumes Correct answer.

Explanation

A field model resolves the flow field on a computational grid, so it captures irregular geometry, multi-room coupling and local phenomena such as stratification and ceiling jets. Zone models assume uniform well-mixed layers and are adequate and far cheaper for simple single-compartment cases.

Question 30Fire science and fire dynamics (combustion, fire growth, flashover, smoke behaviour, compartment fire modelling)

A compartment fire is under-ventilated and the door opening is the only air supply. Which change in behaviour is expected as the opening is progressively reduced while the fuel supply remains constant?

  1. The burning rate rises because the reduced opening concentrates the hot gases and increases combustion efficiency
  2. The burning rate becomes limited by air inflow and unburnt fuel and carbon monoxide in the exhaust increase Correct answer.
  3. The heat release rate remains constant while the smoke layer temperature falls sharply
  4. The fire becomes fully fuel-controlled and combustion efficiency approaches unity

Explanation

Once the air supply falls below what stoichiometric combustion of the fuel requires, the fire becomes ventilation-controlled: the mass burning rate scales with the air inflow, and incomplete combustion raises carbon monoxide and unburnt fuel yields. This is why under-ventilated compartment fires are a greater toxicity hazard.

Question 31Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

Under the Hong Kong Code of Practice for Minimum Fire Service Installations and Equipment, a sprinkler system is classified as which type of fire service installation?

  1. A structural fire resisting element
  2. An active fire service installation Correct answer.
  3. A means of escape provision
  4. A passive fire protection measure

Explanation

Sprinkler systems detect or suppress fire using water delivered under pressure and therefore count as active fire service installations, because they require operation of equipment rather than relying on fixed construction. Passive protection instead refers to elements such as fire resisting construction and compartmentation.

Question 32Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

In a building with a single protected staircase serving multiple storeys, what is the primary purpose of providing a protected lobby at each storey entrance to the staircase?

  1. To store firefighting equipment near the stair
  2. To limit smoke entry into the staircase enclosure Correct answer.
  3. To provide a refuge space for wheelchair users
  4. To increase the usable floor area of the storey

Explanation

A protected lobby acts as a buffer zone between the accommodation and the stair enclosure, restricting the migration of smoke into the staircase so that the escape route remains tenable. It supplements, but does not replace, the fire resistance of the enclosing construction.

Question 33Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

A compartment wall separating two parts of a building must resist fire from either side. Which property of the wall is being described?

  1. Insulation only
  2. Fire resistance including both integrity and insulation from each side Correct answer.
  3. Surface spread of flame classification
  4. Integrity only

Explanation

A compartment wall must maintain integrity, preventing passage of flame and hot gases, and insulation, limiting temperature rise on the unexposed face, and it must do so when exposed from either side. Surface spread of flame is a separate reaction-to-fire property of lining materials.

Question 34Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

A fire door is fitted with a self-closing device and is held open by a fusible link release. What is the main function of this arrangement?

  1. To allow the door to close automatically on fire detection or link fusion Correct answer.
  2. To reduce the acoustic performance of the wall
  3. To permit the door to be locked during escape
  4. To increase the fire resistance rating of the door leaf

Explanation

Hold-open devices linked to a fusible link or detection system allow the door to be kept open in normal use while ensuring it closes to restore the compartment line when fire occurs. The rating of the door leaf comes from its construction and certification, not from the release mechanism.

Question 35Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

In means of escape design, what does the term travel distance refer to?

  1. The width of the escape route measured at the narrowest point
  2. The vertical distance from the top floor to the discharge point
  3. The length of the fire hose route from the street hydrant to the building
  4. The distance an occupant travels from any point to a place of safety Correct answer.

Explanation

Travel distance is measured along the actual route an occupant would follow from any point in the accommodation to a place of safety, such as a protected exit or open air. It is a key parameter because longer routes expose occupants to fire and smoke for longer.

Question 36Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

Which of the following best describes a fire resisting period expressed as 60/60/60?

  1. Sixty minutes detection, sixty minutes alarm, sixty minutes suppression
  2. Sixty minutes stability, sixty minutes integrity, sixty minutes insulation Correct answer.
  3. Sixty litres per minute flow for three hose reels
  4. Sixty decibels attenuation for three octave bands

Explanation

Fire resistance is conventionally stated as the period of stability, integrity and insulation achieved under test, so 60/60/60 means sixty minutes for each criterion. Stability applies to load-bearing elements, while integrity and insulation apply to separating elements.

Question 37Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

A required exit route passes through a room used for storage of flammable liquids. What is the correct principle for means of escape design?

  1. The route is acceptable if the door is self-closing
  2. The route is acceptable if the room has a sprinkler system
  3. The route should not pass through a room of higher fire risk than the accommodation it serves Correct answer.
  4. The route may pass through if the storage is limited to the daytime

Explanation

Escape routes should not pass through areas of higher fire risk, because a fire there could cut off the only route before occupants have escaped. Where such a route is unavoidable, the risk room should be separated and alternative protection provided.

Question 38Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

Which component is specifically intended to prevent the spread of fire and smoke through a ventilation duct where it passes through a compartment wall?

  1. A break-glass call point
  2. A fire damper Correct answer.
  3. A hose reel
  4. A smoke detector

Explanation

A fire damper closes automatically on detection of fire or on fusible link operation to maintain the integrity of the compartment where a duct penetrates it. Detectors, hose reels and call points serve other functions and do not seal the penetration.

Question 39Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

A designer is assessing a 20-storey office building and must determine the fire resistance period for the structural frame. Which factor has the greatest influence on the required period under a performance-based approach?

  1. The type of window glazing used on the facade
  2. The number of parking spaces in the basement
  3. The building height and the time needed for full evacuation Correct answer.
  4. The colour scheme of the internal finishes

Explanation

Fire resistance periods are set so that the structure remains stable for the duration of evacuation and firefighting, which increases with building height and occupancy. Height and evacuation time are therefore the dominant determinants, while finishes and glazing affect other aspects of fire safety.

Question 40Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

In a building where the exit route width is determined by occupant capacity, a route serving 300 occupants is required to provide a certain aggregate width. If the code allows 5 mm per person, what minimum aggregate exit width is required?

  1. 2500 mm
  2. 2000 mm
  3. 1000 mm
  4. 1500 mm Correct answer.

Explanation

Multiplying 300 occupants by 5 mm per person gives 1500 mm of aggregate exit width. The result must still be checked against minimum individual exit widths and the number of available exits.

Question 41Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

A protected exit staircase in a high-rise building discharges at ground level into a lobby that opens directly onto a public street. Why is this arrangement preferred over discharging the staircase directly into an internal corridor?

  1. It allows occupants to reach a place of safety without re-entering the building Correct answer.
  2. It removes the need for any fire doors in the building
  3. It reduces the construction cost of the staircase
  4. It increases the fire resistance rating of the staircase walls

Explanation

Discharge to open air or a protected lobby leading to open air ensures occupants reach a place of safety and do not have to re-enter the building at risk. This principle underpins the design of exit discharge at ground level.

Question 42Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

A compartment floor is penetrated by a services riser containing plastic drainage pipes. What is the appropriate treatment to maintain compartmentation?

  1. Installing a smoke detector inside the riser
  2. Sealing the penetration with a tested fire stopping system around the pipes Correct answer.
  3. Painting the pipes with intumescent paint only
  4. Leaving the penetration open for future maintenance

Explanation

Penetrations through compartment floors must be sealed with a fire stopping system tested for the pipe material and diameter so that the fire resistance of the floor is maintained. Intumescent paint on pipes alone does not seal the annular gap, and detectors do not restore compartmentation.

Question 43Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

A single-storey workshop has one exit and a maximum travel distance of 20 m to that exit. Which additional measure most directly compensates for the limited number of exits?

  1. Reducing the ceiling height
  2. Increasing the fire resistance of the roof
  3. Providing an automatic sprinkler system and early warning Correct answer.
  4. Adding more windows for natural light

Explanation

Where the number of exits is limited, active protection such as sprinklers and early warning reduces the likelihood that the single exit becomes unusable before occupants escape. Structural or geometric changes do not address the risk of the exit being blocked.

Question 44Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

A fire door on a corridor is required to have a fire resistance period of 60 minutes. Which of the following is the most appropriate way to demonstrate compliance?

  1. Select a door set with a certified test rating to the relevant standard for the required period Correct answer.
  2. Choose a solid timber door of any thickness
  3. Assume that a metal door automatically achieves 60 minutes
  4. Rely on the door being closed during a fire

Explanation

Compliance is demonstrated by a door set certified by test to the relevant standard for the required period, including the frame, hardware and seals. Material type alone does not establish a fire resistance period.

Question 45Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

A basement shop has no direct access to open air and relies on a protected staircase. What additional provision is typically required to protect occupants and firefighters in such a basement?

  1. A larger shop frontage
  2. A higher ceiling finish classification only
  3. Additional display lighting
  4. A smoke ventilation system for the basement accommodation Correct answer.

Explanation

Basements present a high risk because smoke and heat cannot vent naturally, so smoke ventilation or equivalent provisions are typically required to keep escape routes and firefighting access tenable. Shop frontage, lighting and finishes do not address the smoke logging problem.

Question 46Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

In a performance-based fire engineering approach, a designer proposes a smoke control system to maintain a tenable layer above the escape route. Which acceptance criterion is most directly relevant?

  1. The fire resistance of the floor slab
  2. The number of fire extinguishers provided
  3. The colour of the smoke
  4. The maintained smoke layer height and visibility along the escape route Correct answer.

Explanation

Smoke control designs are assessed against criteria such as maintained smoke layer height, visibility and temperature along the escape route for the required evacuation time. These criteria directly relate to tenability for occupants.

Question 47Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

A building is to be provided with a dry rising main. In which situation is a dry rising main most appropriate rather than a wet rising main?

  1. Where the building is a single-storey warehouse
  2. Where the building is tall and the water supply is reliable throughout the year
  3. Where the building height exceeds the threshold but the water supply cannot be guaranteed to be permanently charged Correct answer.
  4. Where the building has no staircase

Explanation

A dry rising main is used where a permanently charged wet system cannot be assured, for example because of frost risk or unreliable supply, so firefighters can charge it from a fire service connection. A wet main is preferred where the supply is reliable and the building is tall.

Question 48Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

A fire compartment boundary is formed partly by a wall and partly by a glazed screen. What principle governs the fire performance of the glazed screen?

  1. The glazing can be ignored if it is laminated
  2. The glazed screen must achieve fire resistance equivalent to the compartment boundary it forms Correct answer.
  3. The glazing may be omitted from the assessment
  4. The glazing only needs to resist surface spread of flame

Explanation

Where a compartment boundary includes glazing, the glazing must provide fire resistance equivalent to the rest of the boundary so that the compartment line remains effective. Ordinary glazing may fail rapidly under fire conditions unless it is specifically rated.

Question 49Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

A designer is considering using a fire engineering analysis to justify a longer travel distance than the prescriptive limit. Which condition is essential for such an alternative approach to be accepted?

  1. The analysis must be prepared by the contractor rather than the designer
  2. The analysis must rely only on the prescriptive codes
  3. The analysis must reduce the construction cost
  4. The analysis must show that occupants can reach a place of safety before conditions become untenable Correct answer.

Explanation

An alternative approach is acceptable only where it demonstrates, by accepted engineering methods, that occupants can escape before tenability limits are exceeded. The qualification of the preparer and the cost outcome are not the acceptance criteria.

Question 50Fire safety design and codes (means of escape, fire resisting construction, compartmentation, active and passive fire protection)

In a building with a phased evacuation strategy, what distinguishes phased evacuation from simultaneous evacuation?

  1. Evacuation is carried out only by the fire service
  2. Only the floor of fire origin and adjacent floors are evacuated initially Correct answer.
  3. Occupants remain in place indefinitely
  4. All occupants evacuate at the same time using all exits

Explanation

Phased evacuation moves the fire floor and immediately affected floors first, with other floors evacuated later if required, which suits tall buildings with protected stairs and voice alarm systems. Simultaneous evacuation moves all occupants at once.