RIBA Guerrilla Tactics Fire Back to basics

Transcription

1 RIBA Guerrilla Tactics Fire Back to basics Geoff Wilkinson MBEng MIFireE MRICS MIOD MCMI ICIOB FRSA FFB

2 Agenda Establishing Control Dwelling Houses Lofts Flats Commercial BS9999 Other considerations

3 Building Regulations Approvals What work is controlled Building Work is defined in Regulation 3 of the Building Regulations. The definition means that the following types of project amount to Building Work : the erection or extension of a building; the installation or extension of a service or fitting which is controlled under the regulations; an alteration project involving work which will temporarily or permanently affect the ongoing compliance of the building,service or fitting with the requirements relating to structure, fire, or access to and use of buildings; the insertion of insulation into a cavity wall; and the underpinning of the foundations of a building.

4 Volume 1 Dwellinghouses Volume 2 Buildings other than Dwellinghouses (including flats)

5 Regulation or Guidance?

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7 Section 1 Fire Detection and Fire Alarm System: Installation of smoke alarms or automatic fire detection and alarm system can significantly increase the level of safety by giving early warning. All dwelling houses should be provided with a fire detection and fire alarm system in accordance with BS :2004 to a least Grade D Category LD3 Standard. Battery backup and located in the circulation spaces. Large dwellinghouse (storey exceeds 200m2) - Grade B, LD3 Large dwellinghouse with 3+ storeys Grade A, LD2 New habitable room provided above ground Fire alarm needed New habitable room on ground with no final exit Fire alarm needed

8 Loft Conversions: The alternative means of escape for loft conversion has been removed For loft conversion within a twostorey dwellinghouse, you should have a protected stairway or the top storey should be separated from the lower storeys by fire resisting construction and be provided with an alternative escape route (Par 2.6 & Diagram 2(a) 2(b) and 3) Doors to be FD20(E20) fire door in suitable frame no self closing device required.

9 Loft Conversions: Building Regulations CPD

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11 Loft Conversions:

12 Open Plan Arrangements:

13 Residential Sprinklers Sprinkler systems installed in dwelling houses can reduce the risk to life. Sprinkler protection can also sometimes be used as a compensatory feature. System should be designed and installed in accordance with BS 9251:2005 Sprinkler systems for residential and domestic occupancies. Where sprinklers are provided then sprinkler protection throughout the building is required. BUT where used as a compensatory feature to address a specific risk or hazard it may be acceptable to protect only part of a building. Many alternative or innovative fire suppression system available. Where these are used it is necessary to ensure that such systems have been designed and tested for use in domestic buildings and are fit for their intended purpose.

14 Fire Alarms in flats: The guidance on smoke alarms in flats has been amended such that alarms should be installed in accordance with BS :2004. Simple guidance has been retained, in the form of a commentary on this standard. All smoke alarms should have a standby power supply. Fire Alarms: The guidance for buildings other than dwellings has been updated to take account of the 2002 edition of BS :2002

15 Means of escape flats: Self closing devices are only required to flat entrance doors and doors enclosing common staircase Locks and child resistant safety stays may be provided on escape windows New guidance has been provided on the provision of inner rooms and galleries.

16 Flats with more than one storey: Four acceptable approaches where no external ground entrance with floor more than 4.5m above ground level Provide alternative exits to all habitable rooms above entrance level. Protected landing and alternative exit If the floor above and below do not exceed 7.5m then provide a protected stair and smoke detection in all habitable rooms and heat in kitchens. Provide a protected stair plus a sprinkler system to BS9251 (some detection still required)

17 Ventilation of stairs: For small single stair building vent of 1m2 free area, each floor or head of stair operated remotely by fire brigade Otherwise Natural:- Vent located in corridor or lobby adjoining the stair at least 1.5m2 And top of stair 1.0m2 In single stair buildings vents on the fire floor and head of stair should be actuated by smoke detection in common areas.if 2 stairs then vents may be manual.

18 Ventilation of common corridors: New diagrams for both single stair and more than one stair. Grey shaded areas denote zone requiring ventilation, either wall vent or smoke shaft Beware of engineered solutions in social housing

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20 Fire Safety Information: A new Regulation (16B) has been introduced to ensure that sufficient information is recorded to assist the eventual owner/occupiers/employer to meet their statutory duties under the Regulatory Reform (Fire Safety) Order The person carrying out the work must provide sufficient information for persons to operate and maintain the building in reasonable safety. The information and level of detail necessary will vary depending on the nature and complexity of the building s design. Appendix G provides advice on the sort of information that should be provided. Or follow BS 5588 part 12/BS9999 (more later)

21 Typically As built plan, and details of Escape routes, compartmentation, cavity barriers. Fire doors, ironmongery, hardware. Fire alarm details, signage, dry and wet risers. Sprinkler layouts\design\maintenance etc Smoke control systems. Any design assumptions made.

22 B1 Fire Alarms Building Regulations CPD

23 B1 Number of Escape Routes

24 B1 Travel Distance Building Regulations CPD

25 B1 Dead Ends Building Regulations CPD

26 B1 Inner Rooms i. the enclosures (walls or partitions) of the inner room should be stopped at least 500mm below the ceiling, or ii. a suitably sited vision panel not less than 0.1m2 should be located in the door or walls of the inner room, to enable occupants of the inner room to see if a fire has started in the outer room, or iii. the access room should be fitted with a suitable automatic fire detection and alarm system to warn the occupants of the inner room of the outbreak of a fire in the access room.

27 B1 Split Use or Occupancy Where any storey is divided into separate occupancies a. the means of escape from each occupancy should not pass through any other occupancy; and b. if the means of escape include a common corridor or circulation space, then either it should be a protected corridor or a suitable automatic fire detection and alarm system should be installed throughout the storey

28 B1 Numbers/Capacity Building Regulations CPD

29 B1 Numbers/Capacity Building Regulations CPD

30 B1 Refuge + Evac Lifts Building Regulations CPD

31 B1 Refuge + Evac Lifts Building Regulations CPD

32 B1 Basements Because of their situation, basement stairways are more likely to be filled with smoke and heat than stairs in ground and upper storeys. Special measures are therefore needed in order to prevent a basement fire endangering upper storeys. If an escape stair forms part of the only escape route from an upper storey of a building it should not be continued down to serve any basement storey. The basement should be served by a separate stair. If there is more than one escape stair from an upper storey of a building only one of the stairs serving the upper storeys of the building need be terminated at ground level. Other stairs may connect with the basement storey(s) if there is a protected lobby, or a protected corridor between the stair(s) and accommodation at each basement level.

33 B1 General Provisions Fire Resistance

34 B1 General Provisions Fire Resistance

35 B1 General Provisions Door Fastenings

36 B1 General Provisions Vision Panels

37 B1 General Provisions Emergency Lighting

38 B1 General Provisions Exit Signs

39 B1 General Provisions Protected Circuits Where it is critical for electrical circuits to be able to continue to function during a fire, protected circuits are needed. A protected circuit for operation of equipment in the event of fire should consist of cable meeting the requirements for classification as PH 30 (formerly CWZ). It should follow a route selected to pass only through parts of the building in which the fire risk is negligible and should be separate from any circuit provided for another purpose.

40 B1 General Provisions M + E

41 B2 Linings Building Regulations CPD

42 B3 Structural Fire Resistance

43 B3 Compartments Building Regulations CPD

44 Compartment Walls: The predicted deflection of a floor, in the event of a fire, should be accommodated into the design of compartment walls

45 B3 Cavity Barriers & Fire Stopping

46 B5 Fire Service Access Building Regulations CPD

47 BS 9999 Risk Based Approach The guidance on the provision of means of escape and on construction has been developed to reflect the nature of the occupants the use of the buildings as well as the likely fire growth resulting risks associated with that use Designed for whole life of building not just design phase No need for Fire Engineer!! Not for dwellings

48 Build up the risk profile Table 2 Occupancy Characteristics

49 Table 3 Fire growth rates

50 Occupancy characteristics

51 Occupancy risk profiles

52 You can vary risk profile through additional fire protection measures Such as; Ventilation (self-break windows, doors) Enhanced fire detection & alarms (voice) High ceilings Can lead to potential benefits; Lower periods of fire resistance Larger compartment sizes Longer travel distances Narrower escape routes (doors, corridors, stairs)

53 Fire detection & alarm systems minimum level (table 8)

54 Base standard travel distances

55 Part B solution 500 people x 5mm = 2500mm wide door BS 9999 solution 500 people x 3.6mm = 1800mm wide door

56 Example 1 - To convert and extend existing office to a shop Existing Floor area: 126m x 30m currently has 2 stair cores Floor to ceiling height: 4.6m 5 floors: Height of top occupied storey 19.2m (Building height 24m)

57 . BS9999 Process Step 1 - Occupancy characteristic (Table 2): B Step 2 Fire growth rate (Table 3): From 2 or 3 depending on shop contents. Step 3 Risk profile (Table 5 ): Assume B2 (white goods) for this example

58 Lets look at ADB ADB says base standard:- Travel Distance: 18m and 45m single/multidirectional Fire alarm: BS5839 says Category Manual Structural fire resistance (with no sprinklers): 90 minutes Whereas BS9999 says base standard:- Start travel distance is: 20m and 50m (increase in 2m and 5m on example) Fire alarm: (Table 8) says Category Manual Structural fire resistance (Table 25 independent of ventilation): 90 minutes

59 1. Effects of ventilation Diagram 1 indicates windows exceed minimum as set out in Table 27 therefore complies with ventilation conditions for reduced structural fire resistance in Table 26 and this is now 75 minutes saving of 15 minutes fire rating to all structural elements.

60 Enhanced AFD Where a clear benefit resulting from the addition of detection and warning systems is demonstrated and is appropriate to the circumstances, a 15% increase in allowable travel distance and a 15% reduction in door width, corridor width and stair width can be applied. Depending on the type of occupancy and level of management within the building, the provision of an automatic detection and alarm system, primarily utilising smoke detectors and incorporating an informative warning system such as voice alarm, might allow longer travel distances and narrower doors.

61 2. Effect of adding a voice alarm (BS5839 Pt8) A flat 15% increase in travel distance and the same percentage reduction in door, stair and corridor widths is granted. Extra travel distance: 20m goes to 23m and 50m goes to 57.5m Extra floor space: 150sq/m in dead end zones and 750sq/m in central zone

62 3. Effects of ceiling height Diagram 1 indicates ceiling height (4.1m) as greater than 4m but below 5m so Table 16 allows 10% increase in travel distance and the same percentage reduction in door, stair and corridor widths.

63 Cumulative extra travel distance 23m goes to 25.3m and 57.5m goes to 63.25m Refer now to Absolute maximums (Table 17): 24m and 75m

64 Table 17 Maximum Acceptable Distances

65 Management of fire safety It is a fundamental assumption that features described in BS9999 will require management and maintenance throughout the life of the building. It is now widely acknowledged that the design and engineering put into a building for life safety can only do its job properly if it can be managed maintained and tested over the whole life of the building, and if the staff are trained to handle incidents and operate effective and tested emergency plans.

66 Table 6 Corresponding Expected Management Levels It should be noted that if a management profile is established during a shell build design this needs to form part of the fit-out risk assessment

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68 Local Acts Section 20

69 Planning Precautions Storage LPG, acetylene or other fuel types Ignition sources Smoking Electrical Fixed and portable electrical equipment Security/arson Site fires Temporary accommodation General fire precautions Means of escape Fire alarms Fire-fighting equipment Emergency procedures An emergency fire plan should be prepared for every site.

70 Contact Geoff Wilkinson Tel: (020) Mob: geoff@thebuildinginspector.org Web: Post: Wilkinson Construction Consultants, 2nd Floor, St John Street, London, EC1V 4PY In association with built for: training for all your built environment training needs