Presentation on theme: "NEBOSH Fire Certificate Element 4 Part 1"— Presentation transcript:
1 NEBOSH Fire Certificate Element 4 Part 1 Issue Oct 2011
2 Fire Protection in Buildings We cant see it coming,, we cant hear it, we cant smell it but we know when it gets us.
3 Building Regulations 2000In general covers new builds and modificationsSchedules A-K contain information on structures, fire, moisture, toxic substances, noise, ventilation, hygiene and drainage.
4 Volume 1 - Dwellinghouses Part B (Fire Safety) of the Building Regulations and Approved Document BVolume 1 - DwellinghousesVolume 2 – Buildings Other Than DwellinghousesFlats (including multi-storey flats & mixed-use buildings) can be found in Volume 2
5 Part B (Fire Safety) of the Building Regulations and Approved Document B Schedule B FireB1 Means of warning and escapeB2 Internal fire spread (linings)B3 Internal fire spread (structure)B4 External fire spreadB5 Access facilities for the fire serviceAppendices regarding fire performance materials with regards test methods
6 Fire Resistant Properties of Common Building Materials Resistance to collapse Load BearingFire & Smoke Penetration IntegrityTransfer of Excessive Heat InsulationResistance of Fire Doors Stop the spread of smoke, fumes or heat.
7 Elements of a Structure a. A member forming part of a structural frame of a building or any other beam or columnb. A load bearing wall or load bearing part of a wallc. A floord. A gallerye. An external wallf. A compartment wall
8 Timber Timber burns at the surface Does not expand when heated Does not collapse suddenlyFire resistance depends on: -Thickness & cross sectional areaTightness of jointsType of woodTreatment
9 Reinforced Concrete Frames Types: - Reinforced, Pre-stressed (pre & post tensioned)Resistant to fireFire resistance depends on type & thickness of concrete used & protection afforded by the concrete to the steel
10 Brickwork & Blockwork Resistant to fire Resistance depends on: - ThicknessPlastering or coatingWhether load bearing or notCavities within the bricks or blocks
11 Structural Steel Non-combustible Steel expansion causes buckling can affect stability of buildingSteel looses strength in a fire
12 Sheet Materials Fibre board can be fire resistant if impregnated Plaster boards retard fire spreadPlywood/chipboard depends on properties of woodPlastic has little fire resistanceGlass breaks unless wired or tempered
13 Lining Materials Mostly non-combustible Some older types may contain wood dustPlaster (calcium hydroxide) has good fire resistance
14 B2 Internal Fire Spread (linings) To inhibit the spread of fire within the building the internal linings shall resist the spread of flame over their surfaces and if ignited a rate of heat release or a rate of fire growth which is reasonable in the circumstances.
15 B3 Internal Fire Spread (structure) The building shall be designed and constructed so that in the event of fire, its stability will be maintained for a reasonably period.Consider:DesignMaterialsCompartmentationShaftsConcealed spaces (cavities)Protection of openings and fire stopping
16 CompartmentationTo prevent fire, heat, and smoke from spreading beyond locations of originationBuilding elements such as fire walls, fire dampers, and fire doors, are designed to seal off one location from the next.Increases the safety by allowing evacuating building occupants because smoke and fire are not able to escape into exit passageways.Containment of fire and smoke reduces property damage and prevents small fires from growing.In order for compartmentation efforts to be effectivefire barriers must be maintained
17 Compartmentation 30 min fire resistance Maintains building structure Allows sufficient time to escapeMinimises destructionAssists firefightingTo prevent fire, heat, and smoke from spreading beyond locations of origination.
20 Openings & VoidsThese can eliminate the protection afforded by the compartmentAny opening will allow fire to spread quicklyVoids eg cable ducts, suspended ceilings & floors provide ready routes for fire spread“Fire Stopping” ensures barriers to fire spread are replaced
23 B4 External Fire SpreadThe external walls of the building shall adequately resist the spread of fire over the walls and from one building to another, having regard to the height, use and position of the building.The roof of the building shall adequately resist the spread of fire over the roof, from one building to another, having regard to the use and position of the building.
24 B1 Means of warning and escape The building shall be designed and constructed so that there are appropriate provisions for the early warning of fire, and appropriate means of escape (MOE) in case of fire from the building to a place of safety and effectively used at all times.
25 B1 Means of warning and escape B1 will be met if:There are routes of sufficient numbers and capacity which are suitably locatedThe routes are sufficiently protected from the effects of fire by enclosure where necessaryRoutes are adequately lit and sign postedAppropriate facilities to either limit the ingress of smoke to the escape routes or to restrict the fire and remove the smokeArrangements for early warningProtection of escape routes
26 Means Of Escape“Structural means forming an integral part of the building whereby persons can escape from fire by their own unaided efforts to a place of safety”Consider – structure, travel, fire, place of safety.Main principles BS5588 and Acop’s and The Building Regulations 2000
27 Strategic Factors Affecting Means Of Escape OccupancyConstructionTime of evacuationExitsTravel DistanceManagement
28 Maximum Travel Distances Where more than one route is available25 m – high risk area45 m – normal risk area60 m – low risk areaWhere only single escape route is available12 m – high risk area25 m – normal risk area45 m – low risk area
29 Escape RoutesStairways, corridors and areas near the fire exits should be kept clear of obstructions and material which can catch fire.The escape route should lead to a final exit and a safe place.If the stairway is not protected, the travel distance should be in line with those for single escape routes and the final exit should be easy to see and get to from the stairway at ground-floor level.High-risk rooms should not generally open directly into a fire-protected stairway.Alternate means of escape usually required
30 Stairs & CorridorsMinimum width 800mm stairs (increases with number of persons) but not to exceed 1.4m unless central handrail fitted1.2m corridorsOne stairway up 4 storeys onlyStairways to have handrailsTreads and risers of stairs of correct dimensionsStructure 30 mins fire resistance
31 Stairs, Corridors and Passages Fire Protection 30 minutes minimumBe ventilatedSub-divide corridors (If longer than 12m)Not cause bottle necksHeight 2mBe continuous to the exit pointCorrect lightingManagement actions to maintain MOE
32 Emergency Lighting Aim To indicate clearly the escape route Illuminate routes to allow safe movementTo ensure call points and equipment can be locatedConsider natural light - day/nightSitingEscape route lightingOpen area lighting – anti-panic lightingHigh risk lightingDifferent typesMaintainedSustainedSelf containedLow level lightingTesting – Daily, Monthly, 6 monthly
33 Signage The H&S (Safety Signs & Signal) Regs 96 Two types- EC Pictorial & BS5449 Pictorial and wordsTypes Include -Directional arrows, equipment, alarms, assembly pointsRead from both sidesNot obscured
34 Fire Doors BS 476 Does not obstruct route when open Self closing with smoke stopsThree hinge, Colour coded rawl plugs. i.e FD 30/30Width 850 if more than 50 personsSmoke sealed – intumescent strips30 minutes fire resistanceEasily opened and in direction of travelMagnetic hold-backs are okayFinal exit to unobstructed place of safetyNever lockedHave visibility panels45 degree ruleRoller shutters should be capable of manual operationAmount – 60= =2 More than 600=3
36 APPROVED DOCUMENT M - THE BUILDING REGULATIONS 1.general guidance on Vision Panel dimensions, however if Vision Panels form part of a fire resisting door set then the area of the glass may be determined by the fire resistance properties and the manufactures’ s specifications etc. 2.All door glazing on traffic routes and public areas should be Safety Glazing Standard, in addition to any fire resistance required.
40 MOE For Vulnerable People Evacuation lifts, refuges and chairsUse of graphic, aural, tactile signagePersonal Emergency Evacuation Plan (PEEP)
41 Fire Detection Smoke Detection Heat Detection Flame Detection Optical or ionisationOptical detects obscuration of light by smokeIonisation detects by change in electrical chargeHeat DetectionFixed rate or temperature riseUsed where there is heat under normal conditions (kitchens)Flame DetectionInfra-red or ultra-violetUsually used with other types
42 Ionisation Smoke Detector Americium 241 enables current to flow between the inner and outer chambers.As smoke enters the detector an increase in voltage occurs between the two chambers.The voltage increase triggers the detector at a preset threshold.Ionisation detectors respond well to fast-burning fires
43 Optical Smoke Detector smoke from a fire scatters the light from the LEDif smoke seen on the two following pulses, the alarm lights up.optical smoke detectors respond well to slow-burning fires.
44 Heat Detector Twin thermistors detect change in heat Difference in temperatures triggers the alarmStatic response detectors have one sensor at preset temperatureThey have wide openings to allow good air movement over the sensing thermistor
45 Flame DetectorA flame detector is designed to detect ultraviolet (UV) or infra-red (IR) radiation emitted by fire.Dual IR flame detectors are sensitive to low-frequency, flickering infra-red radiation.Detector can operate even if the lens is contaminated by a layer of oil, dust, water vapour or ice.Flame detectors are effective in protecting areas where flaming fires may be expected.
46 Alarm Systems Components Automatic detector Manual call point Spot (static)Line (linear heat laid around an area)Beam (of light IR large areas)Sampling (pipe work pulling air through a detector)Scanning (moving/sweeping a large area)Manual call pointAlarm sounderControl panel
47 Categories of Fire Alarms & Detection Systems Systems generally designed & installed to BS 5839Property risk/protection (to summon the Fire & Rescue Service in the early stages of a fire)Category P1 installed throughout all areas of the building.Category P2 Systems installed only in defined parts of a building.
48 Life Risk/ ProtectionCategory M Manual system (call points & sounders only)Category L Automatic fire detection systems intended for the protection of lifeL1 Installed throughout all areas of a buildingL2 Installed only in defined parts of the buildingL3 Designed to give a warning at an early enough stage to enable occupants to escape safely before routes are impassable due to fire, smoke or toxic gases. (other than possibly those in the room of the fires origin)L4 Installed in escape routes comprising of circulation areas (stairways and corridors) Objective is to provide warning of smoke within escape routes.L5 Systems in protected areas and or location of detectors designed to satisfy a specific fire safety objective other than the above categories.
49 Fire Alarm ZoningZones are a convenient way of dividing up a building to assist in location of a fire.Zones are not physical features (normally the zone boundary coincide with walls, floors and fire compartments)Zone basic rules:Single zone should not exceed 2,000m2Two faults should not remove protection from an area > 10,000m2 (for addressable systems) Addressable= Gives unique ID to the actuating device detector/call point which has been activated.Floor area < 300m2 regarded as one zone.Total floor area > 300m2 zones restricted to single floor levelsException to above: stairwells, lift shafts or other vertical shafts should be considered as one or separate zonesThe max distance travelled within a zone to locate the fire should not exceed 60m.
50 Alarm Signalling Objective to warm occupants of a fire situation One sounder located near the control panel on a separate circuitSounders should sound similar to avoid confusionMinimum of 65db in general areas or 5 db above background noise.High noise areas visual indication may be required.Sleeping 75db at bedhead (30 db should be allowed per door so sounder per bedroom is recommended)Impaired hearing other means of signalling may be required
51 Alarm Receiving Centres Permanently manned (normally a commercial organisation)Upon receipt of a fire signal notify the fire service
52 Factors in the Selection of Fire Alarm & Detection Systems Life RiskProcess RiskBehavioural issuesSocial Behaviour Minimising false Alarms (unwanted alarms, Equipment false alarms malicious alarms)Requirements for Vulnerable People (disabilities and/or mobility problems)
53 Requirements for Maintenance & Testing RRFSO 2005 States “ equipment & devices are subject to suitable system of maintenance and maintained in an efficient state.... Good repair”One regime to comply with is would be:Daily Check System is not indicating a fault if required corrective actions are taken.Weekly Check Test the system by operation of a call point (different one each week)Periodic Subject to RA (but should not exceed 6 months)Check system log, visually inspect all items of equipment(obstructed or inappropriate due to change of use), amount of false alarms, standby power, remote signalling ,any other checks required (beam detectors for alignment etc) all call points over the 12 months plus cabling, programming and audible checks.