Fire Safety Design of Buildings PDF

Chapter 2 Fire Safety Design of Buildings Singapore Institute of Technology Dr. An Hui DID: 6592 2074 E-mail: [email protected] Fire Safety Management Chapter 2 ...

Chapter 2 Fire Safety Design of Buildings Singapore Institute of Technology Dr. An Hui DID: 6592 2074 E-mail: [email protected] Fire Safety Management Chapter 2  SIT Internal LEARNING OUTCOMES At the end of this lesson, you will be able to: 1. Discussion the fundamentals of Fire Safety Design 2. Explain the principles of Fire Safety Tactics and their objectives 3. Explain the building design and construction features influencing Fire Safety 4. Explain the purposes and strategies of structure fire precautions 5. Explain the concepts and components in compartmentation 6. Explain means of escape requirements under the Fire Code 7. Explain travel distance, occupant loading and exit capacity, their definitions and calculation 8. Explain the different types of exit facilities and requirements Fire Safety Management Chapter 2 2  SIT Internal CHAPTER OUTLINE 1. Fire Safety Objectives 2. Fire Safety Tactics 3. Fire Safety Components 4. Structure Fire Precautions 5. Means of Escape Fire Safety Management Chapter 2 3  SIT Internal 1. FIRE SAFETY OBJECTIVES 1.1 Fire Safety Objectives Fire Safety Design is aimed at offering an acceptable level of fire safety in building by minimizing the risks associated with fires. Fire Safety Life Property Safety Protection Protecting people Keeping heat away from smoke from buildings NOT AIMED AT PROVIDING ABSOLUTE SAFETY Fire Safety Management Chapter 2 4  SIT Internal 1. FIRE SAFETY OBJECTIVES 1.2 Life Safety Objectives Designing to ensure life safety – to seek reduction on potential injury or deaths to the occupants of the building within an acceptable limits. Fire Safety Management Chapter 2 5  SIT Internal 1. FIRE SAFETY OBJECTIVES 1.3 Property Protection Objectives o The reduction to acceptable limits of the potential for damage to the building and its contents. o The building should be able to continue to function after a fire. o The building can be repaired. o Remain safe for firefighting operations during the fire. Fire Safety Management Chapter 2 6  SIT Internal 1. FIRE SAFETY OBJECTIVES 1.4 Design Considerations Design Objectives o Aesthetical o Functional o Technological o Economical To be successful these objectives need to be integrated. Fire Safety Management Chapter 2 7  SIT Internal 1. FIRE SAFETY OBJECTIVES 1.4 Design Considerations Architect must be conscious of: o Fire Safety Objectives o Fire Safety Tactics Fire Safety Management Chapter 2 8  SIT Internal 2. FIRE SAFETY TACTICS There are 5 tactics available: i. Prevention ii. Communication iii. Escape iv. Containment v. Extinguishment Fire Safety Management Chapter 2 9  SIT Internal 2. FIRE SAFETY TACTICS Success Failure Life Safety Escape Death Success Success Success Failure Failure Failure Prevention Communication Containment Success Success Success Failure Success Failure Property Extinguishment Destruction Protection Fire Safety Management Chapter 2 10  SIT Internal 3. FIRE SAFETY COMPONENTS 3.1 Fire Safety Components Fire Safety 5 Fire Safety Components Tactics Building, Furniture, Escape, Prevention, Fittings, Occupants, Communication, i.e., sprinkler sys. / Extinguishment & hazard materials ,etc Containment Resultant Alter risk to Life & Property Fire Safety Management Chapter 2 11  SIT Internal 3. FIRE SAFETY COMPONENTS 3.2 Acceptability & Equivalency Fire Safety Life Safety OBJECTIVES Property Protection Prevention. Communication. TACTICS Escape. Extinguishment. Containment. Buildings. Fittings. COMPONENTS Furniture. Occupants Fire Safety Management Chapter 2 12  SIT Internal 3. FIRE SAFETY COMPONENTS 3.2 Acceptability & Equivalency Fire Safety Design / Provisions / Regulations Economics, Cost, Convenience, Aesthetic Performance Based Design Acceptable Level of Safety, e.g., Cost – Benefit Analysis Fire Safety Management Chapter 2 13  SIT Internal 3. FIRE SAFETY COMPONENTS 3.2 Acceptability & Equivalency Equivalency ==== “Trade – Off” Concept: Can one Safety Measure being trade-off for another ?????? Example Sprinkler Provision available, can permit reduce in Travel Distance Requirement? Fire Safety Management Chapter 2 14  SIT Internal 3. FIRE SAFETY COMPONENTS 3.3 Building Design & Construction Influencing Fire Safety: i. Fire Propagation a) Fuel load & distribution b) Finish materials & their location c) Construction details influencing fire and production of combustion movement d) Architectural design features Fire Safety Management Chapter 2 15  SIT Internal 3. FIRE SAFETY COMPONENTS 3.3 Building Design & Construction Influencing Fire Safety: ii. Smoke & Fire Gas Movement a) Generation b) Movement o Natural air movement o Mechanical air movement c) Control o Ventilation o HVAC o Barriers o Pressurisation d) Occupant protection o Egress o Refuge spaces Fire Safety Management Chapter 2 16  SIT Internal 3. FIRE SAFETY COMPONENTS 3.3 Building Design & Construction Influencing Fire Safety: iii. Detection, Alarm & Communication a) Activation b) Signal c) Communication system o To and from occupants o To and from DECAM/fire department o Type (automatic or manual) o Signal (audio or visual) Fire Safety Management Chapter 2 17  SIT Internal 3. FIRE SAFETY COMPONENTS 3.3 Building Design & Construction Influencing Fire Safety: iv. People Movement ⁃ Occupant o Horizonal o Vertical o Control o Life support ⁃ Fire fighters o Horizontal o Vertical Fire Safety Management Chapter 2 18  SIT Internal 3. FIRE SAFETY COMPONENTS 3.3 Building Design & Construction Influencing Fire Safety: v. Suppression Systems ⁃ Automatic ⁃ Manual ⁃ Special vi. Fire Fighting Operations ⁃ Access ⁃ Rescue operation ⁃ Venting ⁃ Extinguishment Fire Safety Management Chapter 2 19  SIT Internal 3. FIRE SAFETY COMPONENTS 3.3 Building Design & Construction Influencing Fire Safety: vii. Structural Integrity ⁃ Building structural system (fire endurance) ⁃ Compartmentation ⁃ Stability viii. Site Design ⁃ Exposure protection ⁃ Fire fighting operations ⁃ Personnel safety ⁃ Miscellaneous (water supply, traffic access, etc.) Fire Safety Management Chapter 2 20  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS Staircase made of Timber (Combustible) Fire Safety Management Chapter 2 21  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS Fire Safety Management Chapter 2 22  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS Openings (Fire Spread through openings without compartmentation) Fire Safety Management Chapter 2 23  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 260 Bangkit Road Fire Safety Management Chapter 2 24  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.1 Introduction o Fire can burnt out by itself or spread o What are the ways that it can spread? Fire Safety Management Chapter 2 25  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.2 Objectives & Strategies a) To prevent the collapse of buildings in the event of fire by the provision of a stable and durable form of construction b) To prevent the spread of fire from one unit to another within the building c) To prevent the spread of fire between adjoining buildings by adequate separation d) To control the use of combustible building materials to control fire development Fire Safety Management Chapter 2 26  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.3 Purpose of Compartment Wall and Floor a) Form a complete barrier to fire between the compartments they separate, b) Have appropriate fire resistance to comply with the relevant requirements of Fire Code, and c) Be constructed of non-combustible materials. Fire Safety Management Chapter 2 27  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.1 Provision of Compartment Walls and Compartment Floors (General) Size Limitation of Building and Compartment Maximum Maximum Compartments Floor Area Cubical Extent Compartment below ground level. No 2000 m2 7500 m3 compartment to comprise more than one storey. Compartments between average ground level and a height of 24m. No compartment to comprise 4000 m2 15000 m3 more than 3 storey. Compartments above a height of 24m from average ground level. No compartment to comprise 2000 m2 7500 m3 more than one storey. Fire Safety Management Chapter 2 28  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.1 Provision of Compartment Walls and Compartment Floors (General) 8th storey 7th storey 6th storey Compartmentation 5th storey by Height 24m 4th storey 3rd storey 2nd storey 1st storey No compartment to comprise > 3 storeys Fire Safety Management Chapter 2 29  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.2 Provision for Atrium Design ATRIUM SMOKE CONTROL SYSTEM REQUIRED Smoke extraction through atrium void 4th storey AUTOMATIC SPRINKLER 3rd storey 6m minium SYSTEM REQUIRED 2nd storey Area of void > 93 m2 1st storey Special consideration for atrium design which comprises more than 3 storeys of interconnecting floor area. Fire Safety Management Chapter 2 30  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.3 Exemption for HDB MSCP Open-sided multi-storey car park Min. 2000 mm < 24 m ❑ Open sided car parking decks having not less than 50% of the sides permanently open and such openings being evenly distributed as to provide cross ventilation to all parts of the car parking areas. Fire Safety Management Chapter 2 31  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.4 Exemption for Basement Car Parking 1st Storey G.L. Ramp Basement 1 Compartmentation is Car park Basement 2 relaxed where Sprinkler System and Rising Main are provided Basement 3 Special consideration for basement used solely for car parking (no occupants). Fire Safety Management Chapter 2 32  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.5 Provision for Separation of Different Usage A A FD1 FD1 FD2 Factory Warehouse Compartment wall FD1 FD1 FD1 FD1: Fire door min. half hour fire resistance rating FD2: Fire door having the same fire resistance rating as the compartment wall Separation of purpose groups Fire Safety Management Chapter 2 33  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.5 Provision for Separation of Different Usage Compartment wall and floors Factory Warehouse Factory Warehouse Factory Warehouse Section A - A Compartment walls and floors shall be constructed of non- combustible materials to have minimum 1 hour fire resistance rating Fire Safety Management Chapter 2 34  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.6 Provision for Fire Command Centre Fire fighters access at ground level Staircase A Fire Fire Lift Lobby Command Centre Fire lift Min. 2 hour fire rated wall Fire doors Line of sight Fire Safety Management Chapter 2 35  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.7 Provision for Kitchen Compartment o In room/space where open-flame cooking activities are carried out, except for residential units in PG I and II buildings, the kitchen shall be separated from other parts of the same building by compartment wall and floor having fire resistance of at least 1 hour; o Doors shall have fire resistance of half an hour and fitted with automatic self-closing device; o Kitchen exhaust (flue) shall be fire rated (same fire resistance as compartment wall) and discharge directly to external. Fire Safety Management Chapter 2 36  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.7 Provision for Kitchen Compartment Roof Flue or duct to be Factory encased in non- combustible material having the same fire resistance as the compartment floor through which it passes Factory Canteen kitchen Corridor corridor Half hour fire door and one hour fire rated wall Fire Safety Management Chapter 2 37  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.8 Kitchen Separation Exemption a) Kitchen is fitted with approved extinguishing system; or b) With at least 25% of the perimeter walls open directly to external and provided any part of the floor space is within 9 m from the nearest opening; or c) With at least 50% of the perimeter walls open directly to the external and provided any part of the floor space is within 12 m from the nearest opening; or d) When an eating establishment is separated from other parts of the same building by walls and floors having fire resistance of at least 1 hour and doors having fire resistance of at least half an hour; and provided - ⁃ For a sprinkler protected building, there is no need to control the floor area of the compartment; or ⁃ For a non-sprinkler protected building, the floor area of the compartment shall not exceed 150 m2. Fire Safety Management Chapter 2 38  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.8 Kitchen Separation Exemption B A The total area of opening (A+B) shall be at least 25% (at least 50%) of the perimeter walls of the establishment Full height Opening B wall Opening A Fire Safety Management Chapter 2 39  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.9 Provision for Cinema FD ❑ A cinema shall be separated FD Stage Cinema 4 FD Stage Cinema 3 FD Stage Cinema 2 FD Stage Cinema 1 from other parts of the same building, which is of a different purpose group. FD FD FD FD ❑ At least 2-hour fire FD FD FD Lobby FD FD Compartment walls resistance for compartment FD walls and floors for non- Car park sprinkler protected FD building. FD Shopping Area ❑ 1-hour fire resistance for a building is protected by an FD: Fire Door automatic sprinkler system. Fire Safety Management Chapter 2 40  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.10 Provision for Spray Painting Room Interior Exterior Spray Painting Room 2 hour compartment wall and door Fire Safety Management Chapter 2 41  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.11 Provision for Hotel LINEN GR GR GR STORE GR GR GR ROOM FD FD FD FD FD FD FD FD FD FD FD FD FD FD FD FD FD FD FD FD GR GR GR GR GR 1 hr fire GR GR GR GR GR rated walls FD: Min. ½ hr fire door GR: Guest room ❑ Each guestroom or accommodation unit shall be individually compartmented (fire resistance rating of at least 1 hour) Fire Safety Management Chapter 2 42  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.12 Provision for Dormitory 1st Storey Plan D D D D Kitchen FD FD S1 FD FD FD FD FD FD FD FD S2 FD FD Cross-ventilated internal corridor FD FD FD FD FD FD FD FD D D D D FD: Min. ½ hr fire door 2nd Storey Plan D: Dormitory S1, S2 = Exit Staircase D D D D D FD S1 FD FD FD FD FD FD FD FD S2 FD FD Cross-ventilated internal corridor FD FD FD FD FD FD FD D D D D ❑ Each dormitory bedroom shall be individually compartmented (fire resistance rating of at least 1 hour) Fire Safety Management Chapter 2 43  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.13 Provision for Store Room Store 2 FD Warehouse FD FD FD Internalcorridor Internal corridor FD FD FD FD FD FD FD FD FD Store 3 Factory Store 1 Factory Factory ❑ For non-sprinklered buildings, if the area of the store room exceeds 10 m², it shall be individually compartmented (1 hour fire resistance). ❑ No compartmentation is required for a store room which is housed within a sprinklered protected building. Fire Safety Management Chapter 2 44  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.14 Provision for Unprotected Openings Examples of Unprotected Areas in External Wall External wall with a combustible material more than 1 mm thick applied or attached to the external face Windows or other opening Panels with a fire resistance of less than that required for external wall Door Fire Safety Management Chapter 2 45  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.14 Provision for Unprotected Openings Unprotected areas and enclosing rectangles Protected Units shaft 8400 1800 Rectangle 1 Wall having required fire 1800 resistance 5400 10800 Rectangle 2 Panel not having the 2400 required fire resistance % of unprotected areas to the area of enclosing rectangle is used to calculate the separation (set back) distance required Fire Safety Management Chapter 2 46  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.14 Provision for Unprotected Openings Notional Boundary Notional Boundary a b Building A Building B Boundary situated such that a and b can comply with regulations Fire Safety Management Chapter 2 47  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.15 Provision for Separating Wall Combustible material Building A Building B shall not be carried over top or through separating wall to prevent the spread of fire 2nd Storey Separating wall (at least 1st Storey 1 hour fire resistance) Opening not permitted. E.g. door Fire Safety Management Chapter 2 48  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.16 Provision for Protected Shaft Construction Shaft containing a lift Shaft containing exit staircase Opening for cables Vent opening Shaft must not contain any pipe conveying gas or oil, nor any ventilation duct Fire resisting doors “Protected Shafts” include staircase, lift shafts, chutes, ducts or any other shaft enabling movement of people, goods, air, pipes, etc. Fire Safety Management Chapter 2 49  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.16 Provision for Protected Shaft Construction Door Protected shaft Protected shaft Compartment wall Compartment floor Door Opening Plan View Section View A door should have the same fire resistance rating as the compartment wall and complies with the relevant requirements of Cl.3.4 Fire Safety Management Chapter 2 50  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.17 Provision for Protected Staircase 10 air change/hr Fire Fire damper Fire-lift lobby Lift Ventilation shaft serves fire lift lobby only Ventilation shaft Protected staircase serves staircase only Fire extinguisher Separate ventilation shafts are required to be provided for the staircase and fire lift lobby. Fire Safety Management Chapter 2 51  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.18 Provision for Concealed Spaces (Raised Floor) Floor finish Metal sheet (Class 0) Cut edges or sides of panel covered Combustible core with metal sheet e.g. chipboard (Class 0) Metal sheet (Class 0) Sprinkler head F.F.L Decking of the raised floor shall be constructed of non-combustible material or where combustible material is used as core material, if allowed in the case of sprinkler protected buildings, the top, bottom, all sides and cut edges shall be covered with material with surface property complying with Class 0 Fire Safety Management Chapter 2 52  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.19 Restriction of spread of flame over surface of walls and ceilings a) Class 0 – Surface of no Flame Spread. b) Class 1 – Surface of Very Low Flame Spread. Those surfaces on which not more than 165 mm mean spread of flames occurs under the test conditions. c) Class 2 – Surface of Low Flame Spread. Those surfaces on which during the 1st 1.5 minutes of test, the mean spread of flame is not more than 215 mm and the final spread does not exceed 455 mm under the test conditions. Fire Safety Management Chapter 2 53  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.19 Restriction of spread of flame over surface of walls and ceilings a) Class 3 – Surface of Medium Flame Spread. Those surfaces on which during the 1st 1.5 minutes of test, the mean spread of flame is not more than 265 mm and during the 1st 10 minutes of test is not more than 710 mm under the test conditions. b) Class 4 – Surface of Rapid Flame Spread. Surfaces on which the spread of flame exceeded the limit of Class 3. Fire Safety Management Chapter 2 54  SIT Internal 4. STRUCTURE FIRE PRECAUTIONS 4.4.19 Restriction of spread of flame over surface of walls and ceilings Fire Safety Management Chapter 2 55  SIT Internal 5. MEANS OF ESCAPE Fire Safety Management Chapter 2 56  SIT Internal 5.1 INTRODUCTION 5.1.1 Introduction o How do we escape? o Corridor/passageway/staircase o Distance to travel o Explain the requirements of means of escape Fire Safety Management Chapter 2 57  SIT Internal 5.1 INTRODUCTION 5.1.2 Objectives o To know i. the calculation of OL Vs EC ii. types of travel distances iii. types of exit facilities Fire Safety Management Chapter 2 58  SIT Internal 5.1 INTRODUCTION 5.1.3 Determination of Exit Requirements Factors affecting the exit requirements are as follows: i. Types of occupancy (purpose group) ii. Floor area iii. Occupant Load (OL) per room/floor iv. Capacity of an exit (EC) of an Exit v. Travel distance to an exit Fire Safety Management Chapter 2 59  SIT Internal 5.2 PURPOSE GROUPS Purpose Groups ❑ PG I Small Residential (eg. bungalow, semi-d, terrace) ❑ PG II Other Residential (residential other than PG I) ❑ PG III Institution ❑ PG IV Office ❑ PG V Shop ❑ PG VI Factory ❑ PG VII Places of public resort ❑ PG VIII Storage See Fire Code, Chapter 1 (Prescriptive Provisions) Fire Safety Management Chapter 2 60  SIT Internal 5.3 OL VS EC Occupant Load (OL) Occupant load of a building, or part thereof, refers to the total number of persons that can occupy such a building, or part thereof, at any one time. The “occupant load” shall be determined by: a) multiplying the floor area(s) available for occupation with the appropriate areas per person as stated in Table 1.4B, unless prior approval is obtained from SCDF for any other occupancy load factors not stated in this table, or b) the number of fixed seating, if applicable, for assembly occupancies. Fire Safety Management Chapter 2 61  SIT Internal 5.3 OL VS EC Capacity of an exit (EC) o Exit capacity is referring to the pre-determined max. no of people that are allowed to use the exit staircases or exit doors. Fire Safety Management Chapter 2 62  SIT Internal 5.3 OL VS EC OL and EC General Criteria o EC > OL (determine the number of exit staircase, width of the exit door and staircase) o Travel Distance (determine the required number and location of the exit staircase) Fire Safety Management Chapter 2 63  SIT Internal 5.3.1 OCCUPANT LOAD (OL) CALCULATION What is Multiple Occupancy? o It is where different types of occupancy (eg office, shops, places of public resorts etc), are co-located in a premises (i.e. floor/building) Exit staircase Smoke free lobby Office S3 7th storey S1 Office Factory Multipurpose S2 hall Factory Factory Factory Factory Restaurant Warehouse Fire Safety Management Chapter 2 64  SIT Internal 5.3.1 OCCUPANT LOAD (OL) CALCULATION What is non-Simultaneous Occupancy? o The floor areas of toilets, locker rooms, lobbies, and corridors that are not occupied at the same time as other rooms or spaces by building occupants, can be omitted from the occupant load calculations of that storey of the building in which the storey is located. Fire Safety Management Chapter 2 65  SIT Internal 5.3.1 OCCUPANT LOAD (OL) CALCULATION Non-simultaneous occupancy Non-simultaneous areas Balcony Pantry Stair A Toilets Office Factory Factory corridor Lift Pantry Factory Factory Storage Stair B Fire Safety Management Chapter 2 66  SIT Internal 5.3.1 OCCUPANT LOAD (OL) CALCULATION Occupant Load (OL) Calculation Effective floor area = Floor Area – non-simultaneous usage OL = Effective Floor Area / OL Factor eg. Office OL = 900(m2) / 10(m2/person)= 90 persons eg. Meeting room OL = 900(m2) / 1.5(m2/person)= 600 persons Fire Safety Management Chapter 2 67  SIT Internal 5.3.1 OCCUPANT LOAD (OL) CALCULATION OL Factor See Fire Code, Chapter 1 Table 1.4B Where to find this? (Prescriptive Provisions) Fire Safety Management Chapter 2 68  SIT Internal 5.3.2 EXIT CAPACITY (EC) CALCULATION Determination of Exit Requirement Available from Fire Code, Chapter 2, Table 2.2 Fire Safety Management Chapter 2 69  SIT Internal 5.3.2 EXIT CAPACITY (EC) CALCULATION Determination of Exit Requirement Staircase width Corridor’s door width Fire Safety Management Chapter 2 70  SIT Internal 5.3.2 EXIT CAPACITY (EC) CALCULATION Exit Capacity (EC) Calculation o Determined by the width of door/corridor and exit staircase. o 1 unit of (x) = 500mm o 0.5 unit of (x) = 250mm Determine EC of Exit door e.g. 850mm width door EC = Actual door width/(x) = 850mm/500mm = 1.7 units of (x) ≈1.5 units of (x) (always round down) EC = 1.5 units of (x) x 80 (persons/unit width (x)) = 120 persons Fire Safety Management Chapter 2 71  SIT Internal 5.3.2 EXIT CAPACITY (EC) CALCULATION Determine EC of Staircase e.g. 1250mm width staircase EC = Staircase width/(x) = 1250mm/500mm = 2.5 units of (x) EC = 2.5 units of (x) x 60 (persons/unit width (x)) = 150 persons Take the smaller EC (limiting factor) EC of door = 120 persons Staircase EC of staircase width = 150 persons Therefore overall EC of this staircase is 120 persons Corridor’s door Fire Safety Management Chapter 2 72  SIT Internal 5.3.3 OL VS EC CALCULATION EXAMPLE Given o 4 factories of gross area 120m2 each. Each factory has a pantry of size 20m2 o Office has an area of 50m2 o Storeroom has an area of 120m2 o OL factor of factory is 10m2/person, storeroom is 30m2/person) o Staircase A and Staircase B are identical in size. Staircase width is 1500mm and door is 1000mm wide. Calculate OL and EC for this floor Fire Safety Management Chapter 2 73  SIT Internal 5.3.3 OL VS EC CALCULATION EXAMPLE Occupant Load (OL) Calculation o OL of 4 factories = [ (120-20)/10m2 ] x 4 = 40 persons o OL of office = 50/10m2 = 5 persons o OL of storeroom = 120/30m2 = 4 persons o Overall OL = 40 + 5 + 4 = 49 persons Exit Capacity (EC) Calculation o EC of staircase width = 1500/500 x 60 = 180 persons o EC of door = 1000/500 x 80 = 160 persons o Overall EC of 2 staircase = 160 x 2 = 320 persons Fire Safety Management Chapter 2 74  SIT Internal 5.3.3 OL VS EC CALCULATION EXAMPLE Fire Safety Management Chapter 2 75  SIT Internal 5.3.3 OL VS EC CALCULATION EXAMPLE Fire Safety Management Chapter 2 76  SIT Internal 5.3.3 OL VS EC CALCULATION EXAMPLE Fire Safety Management Chapter 2 77  SIT Internal 5.3.4 OL VS EC (ADDITIONAL CRITERIA) OL and EC Additional Criteria o Where a room or space is required to be provided with two exits, each exit shall be of sufficient width to accommodate not less than half the total occupant load. Fire Safety Management Chapter 2 78  SIT Internal 5.3.4 OL VS EC (ADDITIONAL CRITERIA) Acceptable Distribution of Exit Capacity Factory production area (Occupant Load = 360 persons) Stair B Exit capacity = 180 persons Exit capacity = 180 persons Stair A Fire Safety Management Chapter 2 79  SIT Internal 5.3.4 OL VS EC (ADDITIONAL CRITERIA) Not Acceptable Distribution of Exit Capacity Stair B Exit capacity = 120 persons Exit capacity = 240 persons Stair A Factory production area (Occupant Load = 360 persons) Fire Safety Management Chapter 2 80  SIT Internal 5.4 TRAVEL DISTANCE 5.4.1 What is Travel Distance? It is an actual distance that is required to travel from the most remote point in any room or space to the edge of a door opening directly to: A. an exit staircase or B. an exit passageway or C. an open exterior space. Fire Safety Management Chapter 2 81  SIT Internal 5.4 TRAVEL DISTANCE Direct Distance Vs Travel Distance Staircase A Staircase B Office Factory Factory Factory Office Lift C B F G Office E Factory Factory D Anc. Factory Factory Storage Office A AB and AC are Direct Distance measurements annotated by DEFB and DEGC are Travel Distance measurement paths annotated by Fire Safety Management Chapter 2 82  SIT Internal 5.4 TRAVEL DISTANCE Measurement of Most Remote Point 400mm Travel distance Measured from here External Corridor Parapet wall Fire Safety Management Chapter 2 83  SIT Internal 5.4 TRAVEL DISTANCE 5.4.2 One Way Travel Vs Two Way Travel o A one way travel or a “common path” exists if a floor space is arranged such that occupants within that space are able to travel in only one direction to reach any of the exits or to reach the splitting point where they have the choice of two or more routes of travel to remote exits. o The travel distance from the most remote point to the splitting point shall not exceed the permissible one-way travel distance. o At the splitting point, the angle of divergence between any two alternative routes shall not be less than 90 degrees in order that the routes originating from the splitting point can be considered as two-way travel. o The aggregate travel distances of the one-way travel from the most remote point to the splitting point and the continuous two-way travel from the splitting point to the nearest exit shall not exceed the permissible two-way travel distance allowed in Table 2.2A. Fire Safety Management Chapter 2 84  SIT Internal 5.4 TRAVEL DISTANCE Determination of Travel Distance Available from Fire Code, Chapter 2, Table 2.2 Fire Safety Management Chapter 2 85  SIT Internal 5.4 TRAVEL DISTANCE Travel Distance DEFB and DEGC must be within two- way travel distance under Fire Code Table 2.2A DE must be within one-way travel distance under Fire Code Table 2.2A Fire Safety Management Chapter 2 86  SIT Internal 5.4 TRAVEL DISTANCE (ADDITIONAL CLAUSES) Where Area of Refuge is provided in lieu of required exits, travel distance shall be measured to the exit door at the corridor leading to the Area of Refuge Doors at Stair A and D onto Bridge Serve as required exits from Building A at least Stair A Stair B one exit A Staircase Building A at least ½ hour fire Cl.2.2.15(e) Door Cl. 2.2.15(d) D Bridge Building B (Area of Refuge) E separation Stair C Fire Safety Management Chapter 2 87  SIT Internal 5.4 TRAVEL DISTANCE (ADDITIONAL CLAUSES) Exit staircase Open-sided corridor For exit staircases to be entered without the provision of an exit door, the travel distance shall be measured to a position where the exit door would be installed if otherwise required. Fire Safety Management Chapter 2 88  SIT Internal 5.5 EXIT REQUIREMENTS 5.5.1 Minimum Width (exit staircase, corridor) o No exit, exit staircase or other exit facilities shall be narrower than the minimum width requirement as specified under Table 2.2A Fire Safety Management Chapter 2 89  SIT Internal 5.5 EXIT REQUIREMENTS 5.5.1 Minimum Width (exit staircase, corridor) A A/c ledge Measurement of clear width Clear width of corridor External corridor Planter box Parapet wall Min. 1200mm PLAN A A/C compressor Corridor Minimum width (corridor) is 1.2 m G.L SECTIONAL ELEVATION Fire Safety Management Chapter 2 90  SIT Internal 5.5 EXIT REQUIREMENTS 5.5.2 Minimum Width (exit door) o The minimum clear width of an exit door opening shall be not less than 850mm o Small room of 2 people or less is min. 610 mm Clear width (min. 850 mm) Wall 90˚ Wall PLAN Fire Safety Management Chapter 2 91  SIT Internal 5.5 EXIT REQUIREMENTS 5.5.3 Maximum Width (exit staircase) o The maximum width of exit staircases shall be not more than 2000mm. Projection of handrail Projection of handrail (clear width max. 2000mm) (clear width min. 1000mm) Fire Safety Management Chapter 2 92  SIT Internal 5.5 EXIT REQUIREMENTS 5.5.3 Maximum Width (exit staircase) o Where staircases exceed 2000mm in width, handrails shall be used to divide the staircase into sections of not less than 1000mm of width or more than 2000mm of width. Handrails Handrails 1250mm 1250mm 1250mm Fire Safety Management Chapter 2 93  SIT Internal 5.5 EXIT REQUIREMENTS 5.5.3 Maximum Width (exit staircase) o For the purpose of determining the exit capacity of a staircase that is wider than 2000mm that forms part of the required means of escape from any storey of the building, that part of its width in excess of 2000mm shall not be taken into account. Fire Safety Management Chapter 2 94  SIT Internal 5.5 EXIT REQUIREMENTS 5.5.4 Minimum No. of Exit Facilities o There shall be at least two independent exit staircases or other exits from every storey of a building, unless otherwise permitted under other subsequent provisions of the code. Office Store Staircase A Smoke-free lobbies Staircase B Factory production area Reception Fire Safety Management Chapter 2 95  SIT Internal 5.5 EXIT REQUIREMENTS 5.5.4 Minimum No. of Exit Facilities When do we allow single staircase? o In an office, shop, factory and warehouse building, one exit staircase is permitted to serve the upper storeys, if the building is: i. Not more than 4 storey ii. Gross floor area (GFA) not more than 200m2 iii. Habitable Height < 15m iv. Non-combustible construction v. Comply with travel distance vi. Access to the building for fire-fighting appliances complied with. Fire Safety Management Chapter 2 96  SIT Internal 5.5 EXIT REQUIREMENTS 5.5.5 Location of Exits & Access to Exits o Every occupant or tenant within a building or storey of a building shall have direct access to the required exit or exits without the need to pass through the spaces or rooms occupied by other occupants or tenants. Fire Safety Management Chapter 2 97  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6 Smoke Free Approach o Entry at every storey level (including 1st storey) to an exit staircase serving more than four storeys above ground level shall be through any of the following: a) External approach (an external exit passageway or external corridor) b) Smoke-free lobby/fire lift lobby Fire Safety Management Chapter 2 98  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.1 External Approach (External corridor) o Approach to an exit staircase through external corridor Exit staircase A B External corridor Parapet wall Industrial units Distance AB is taken as the Travel Distance from point A No fire rating requirement for entrance door Fire Safety Management Chapter 2 99  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.2 External Approach (External exit passageway) Exit staircase C A FD Fire rated FD external wall D FD FD E B FD FD External Exit Passageway FD FD Office units Parapet wall Distance AB = One-way Travel distance from point A Distance CD or CE = Two-way Travel distance from point C All doors opening to external exit passageway shall be fire rated (at least ½ hour) FD – Fire rated exit door Fire Safety Management Chapter 2 10  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.2 External Approach (External exit passageway) Apt A Apt B Min. 3m black wall Fire door 1.8m measured from the External Exit Passageway finished floor level 1m high parapet wall Smoke screen above the external exit passageway External exit passageway is a protected area, which is an extension of the vertical exit staircase. It is used to overcome excessive travel distances. Fire Safety Management Chapter 2 10  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.2 External Approach (External exit passageway) Smoke screen formed by RC, down beam or other non-combustible material Depth to be more than facial beam Min. 3m Min. 1.8m Floor to sill height Fire door Min. 1.8m Section Fire Safety Management Chapter 2 10  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.3 Smoke-free Lobby o When is smoke-free lobby needed? Building more than 4 storeys or below ground level Fire Safety Management Chapter 2 10  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.3 Smoke-free Lobby o Features of smoke-free lobby 1. Wall have at least 1 hour fire resistance. 2. Exit door shall have least half an hour fitted with automatic self-closing device 3. The design of a smoke-free lobby shall be such as not to impede movement of occupants through the escape route 4. The floor area of a smoke-free lobby shall be not less than 3m² and with minimum clear width of 1.2m. 5. Permanent fixed ventilation openings to external > 15% of floor area of the lobby 6. Opening is less than 9m from any part of the lobby 7. When without natural ventilation, mechanical ventilation is required (Emergency to provide 10 air change, normal is 4 air change). 8. Floor gradient shall slope from lift door towards lobby door with a fall not exceeding 1:200 9. A smoke-free lobby, including fire-lift lobby, which acts as buffer space for entry into the protected staircase and use by firefighters during emergency, shall be maintained as common property Fire Safety Management Chapter 2 104  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.3 Smoke-free Lobby o Features of smoke-free lobby Min. 6m Protected staircase width FD Area Unit A 93m2 min. Ventilation opening Max. 9m min. 15% lobby area FD FD Wall of minimum 1 hour fire resistance rating Unit B FD - ½ hr rated self-closing door - Smoke free lobby Fire Safety Management Chapter 2 105  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.3 Smoke-free Lobby o Features of smoke-free lobby served as fire lift lobby 1. Wall have at least 1 hour fire resistance. 2. Exit door shall have least half an hour fitted with automatic self-closing device 3. The floor area of a fire lift lobby shall be not less than 6m² and with minimum clear width of 2m. 4. Permanent fixed ventilation openings to external > 15% of floor area of the lobby 5. Opening is less than 9m from any part of the lobby 6. When without natural ventilation, mechanical ventilation is required (Emergency to provide 10 air change, normal is 4 air change). 7. Floor gradient shall slope from lift towards lobby door with a fall not exceeding 1:200 Fire Safety Management Chapter 2 106  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.3 Smoke-free Lobby o Buildings under Purpose Group II, smoke free approach to exit staircase shall be provided with natural ventilation and lighting. o In the case of Purpose Group III to VIII, smoke free approach to exit staircase, the need to provide mechanical ventilation would be considered if the lobby is internal where natural lighting/ventilation is not possible. Fire Safety Management Chapter 2 107  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.3 Smoke-free Lobby o Mechanically Ventilated Smoke-free Lobby Minimum 4 air change per hour Office Unit A MV Shaft FD Wall of minimum 1 hour fire resistance rating Protected staircase Industrial Unit B FD - ½ hr rated self-closing door - Smoke-free lobby (Min. 3 m2) - Mechanical ventilation shaft serving lobby Fire Safety Management Chapter 2 108  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.3 Smoke-free Lobby o Smoke-free Lobby for Basement Situation 1. In a building comprising single basement storey, the entry to exit staircases need not be through smoke-free lobbies. 2. In a building comprising two, three or four basement storeys, entry at every basement storey level to at least one of the exit staircases serving the basement storeys shall be through a fire lift lobby, even through the exit staircase is not required to be served by a fire lift. However, where the depth of the basement exceeds 9m below the average grade level and fire lifts are required, the entries to the exit staircases with provision of fire lifts at every basement storey level shall be through fire lift lobbies. Fire Safety Management Chapter 2 109  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.3 Smoke-free Lobby o Smoke-free Lobby for Basement Situation 3. In a building comprising more than four basement storeys, the entry to exit staircases serving the basement storeys at every basement storey level shall be through smoke-free lobbies or designated fire lift lobbies. 4. Smoke-free and fire lift lobbies in basement occupancies shall be required to comply with the relevant provisions and shall be mechanically ventilated. Fire Safety Management Chapter 2 110  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.3 Smoke-free Lobby o Smoke-free Lobby for Basement Situation Pressurization shafts Staircase B Fire Lift (Basement storey depth > 9m) Fire lift lobby (6sq.m) Staircase A At least one staircase requires smoke-free lobby, which shall also be served as fire lift lobby. Fire Safety Management Chapter 2 111  SIT Internal 5.6 SMOKE FREE APPROACH TO EXIT STAIRCASE 5.6.3 Smoke-free Lobby o The omission of the smoke-free lobby required leading to the exit staircase of any building exceeding four storeys is allowed under any of the following situations, provided the door opening into the exit staircases shall have 1-hr fire resistance rating and fitted with an automatic self-closing device: i. In an open-sided car park floor where cross-ventilation is provided. In this situation, the fire door to the exit staircase can be ½-hr fire rated. ii. Does not belong to purposes group III & VII. iii. Where the internal exit staircase is provided with pressurization up to (not exceeding) a habitable height of 24m iv. Where an external exit staircase is constructed to comply with the fire code. Fire Safety Management Chapter 2 112  SIT Internal 5.7 PERSON WITH DISABILITIES (PWD) HOLDING AREAS Purpose o A PWD Holding Point shall be provided on all storeys, including all basement levels, except first storey or storey at grade level, for PWDs to safely wait for assistance in evacuation. Siting of PWD Holding Point o There shall be at least two designated PWD Holding Points remotely positioned on every storey of a building except for a building designed with a single exit staircase allowed under this Code. The corridor serving as escape route shall have a minimum clear width of 1.2m. o The PWD Holding Point shall be kept free of obstruction and sited within the following locations/areas in the order of priority: a) Evacuation lift lobby. b) Fire lift lobby. c) Smoke-free lobby or external corridor. d) Exit staircase. Fire Safety Management Chapter 2 113  SIT Internal 5.7 PERSON WITH DISABILITIES (PWD) HOLDING AREAS Siting of PWD Holding Point o The PWD Holding Point located in the above areas shall be positioned away from the edge of the exit staircase and path of person escaping from the occupied space. It shall not reduce/encroach onto the required dimensions/spaces of the above areas. Signage o Where a PWD Holding Point is located, a mandatory sign worded “PWD Holding Point” shall be prominently displayed. Communication o A suitable means of communication, shall be provided between the PWD holding point and FCC or any 24-hourly manned station, for PWDs to call for assistance during a fire emergency. It can be in the form of a distress button or dedicated voice communication. Fire Safety Management Chapter 2 114  SIT Internal 5.7 PERSON WITH DISABILITIES (PWD) HOLDING AREAS Example of incorporating PWD holding area into ERP: o Evacuate any PWD into PWD Holding area within a fire lift lobby o Alert the FCC using the VCS o Wait for rescue from CERT/SCDF o Fire lift can be used for PWD evacuation Incorporate PWD Holding areas into ERP to assist evacuation of PWD Fire Safety Management Chapter 2 115  SIT Internal 5.8 EXIT FACILITIES o Internal exit passageway o External exit passageway o Internal exit staircase o External exit staircase Fire Safety Management Chapter 2 116  SIT Internal 5.8 EXIT FACILITIES 5.8.1 Internal Exit Passageway Clause 2.3.2 (b) External Factory/warehouse FD W Full height FD masonry wall Min. 1.5m - Internal exit passageway FD - Fire door Fire Safety Management Chapter 2 117  SIT Internal 5.8 EXIT FACILITIES 5.8.2 External Exit Corridor/Passageway Ventilation opening permissible 1.1m above corridor floor level Clause 2.3.2 (c) Wall having min. 1 hour fire resistance rating Roof over passageway 1100mm for external corridor and 1800mm for external exit passageway Parapet or balustrade not less than 1m high Fire Safety Management Chapter 2 118  SIT Internal 5.8 EXIT FACILITIES 5.8.3 Internal Staircase & SSL Industrial unit 1 Industrial unit 2 Clause 2.3.3 (a) Pressurized Exit staircase Fire lift Pressurization shaft MV shaft Fire-lift lobby 1-hour rated fire doors Fire Safety Management Chapter 2 119  SIT Internal 5.8 EXIT FACILITIES 5.8.4 External Staircase Clause 2.3.3 (b) 1m Parapet wall Or balustrades wind 1-hour rated fire doors Min 3m separation Industrial Unit 1 Industrial Unit 2 Full height masonry walls Fire Safety Management Chapter 2 120  SIT Internal 5.8 EXIT FACILITIES 5.8.5 Spiral Staircase Clause 2.3.7 Floor line above 10m maximum Tread depth Enlarged for clarity Headroom Max. 175mm 750mm min. 2.1m 300mm Floor line 190mm Min. 750mm Fire Safety Management Chapter 2 121  SIT Internal 5.8 EXIT FACILITIES 5.8.5 Spiral Staircase Fire Safety Management Chapter 2 122  SIT Internal 5.8 EXIT FACILITIES 5.8.6 Exit Ramp Clause 2.3.8 Straight ramp Changes in ramp *Ramp with gradient not greater than 1:12 may be curved to facilitate Change of direction. *Straight ramp shall not be steeper than 1:10 Fire Safety Management Chapter 2 123  SIT Internal 5.8 EXIT FACILITIES 5.8.7 Exit door Exit doors and exit access doors shall open in the direction of exit Clause 2.3.9 travel so that they will not impede the egress Unit A Internal Exit Lobby Staircase Lift Unit B Plan Fire Safety Management Chapter 2 124  SIT Internal 5.8 EXIT FACILITIES 5.8.7 Exit door Clause 2.3.9 Staircase re-entry (1) Every exit staircase enclosure serving more than 7 storeys of a non- residential building, excluding buildings of detention and correctional occupancies, shall allow re-entry from the staircase enclosure to the interior of the building. There shall be at least one level where it is possible to re-enter into the interior of the building from the exit staircase enclosure. (2) The re-entry points shall be located not more than 6 storeys apart. There shall not be more than three storeys above the highest re-entry door in the building. (3) Where re-entry is provided from the staircase enclosure, it shall open into a common corridor that is connected directly to at least one other exit staircase. (4) Exit doors permitting re-entry into the building, shall be identified with a signage “Re-entry door” of at least 50mm lettering height on the staircase side of the exit door. (5) Where locking is required for doors of smoke-free lobby, fire lift lobby or exit staircase on the re-entry floor, they shall be fitted with an electromagnetic/ electromechanical locking device complying with Cl.2.3.9k.(1). For re-entry floor, manual override device shall be provided on both sides of the door. (6) All non-re-entry floors shall be identified with a sign to show the designated re-entry floors on the staircase side of the exit door. Fire Safety Management Chapter 2 125  SIT Internal 6 RECAP 1. Describe the 5 fire safety design tactics 2. Describe the general compartmentation requirements for compartment walls and floors for compartment below ground level. 3. Describe the general compartmentation requirements for compartment walls and floors for compartment above ground level and below 24 m in height. 4. Describe the general compartmentation requirements for compartment walls and floors for compartment above 24 m in height. 5. What is the compartmentation requirement for Fire Command Centre under sprinkler protected building? 6. What is the compartmentation requirement for a cinema under sprinkler protected building? Fire Safety Management Chapter 2 126  SIT Internal 6 RECAP 7. What is non-simultaneous occupancy? 8. A 1.2 m wide exit door is equivalent to ____ units of width (x) 9. A 2.4 m wide exit staircase is equivalent to ___ units of width (x) 10. Where a room or space is required to be provided with two exits, each exit shall be of sufficient width to accommodate _____ total occupant load. 11. The minimum width of an exit door is ____ 12. The minimum width of an exit staircase is ____ 13. The maximum width of an exit staircase is _____ 14. The minimum with of a corridor is ____ 15. When would smoke free lobby be required? 16. What are the general features of a smoke free lobby? 17. What are the general features of a fire lift lobby? Fire Safety Management Chapter 2 127  SIT Internal 6 RECAP 18. What is the smoke free approach and requirement for a building with 4 basement floors? 19. A mixed occupancy floor consists of an office, shop and restaurant with a floor area of 150 m2, 90 m2, and 180 m2, respectively. It is equipped with two exit staircases with the dimensions as shown below. Width Exit door Exit staircase Exit staircase 1 1000 mm 1500 mm Exit staircase 2 1150 mm 1800 mm Please calculate the occupant load and exit capacity of this storey and determine whether the exit staircases are adequate. Fire Safety Management Chapter 2 128