Fire safety: Design - Assignment Example

Fire safety - Design Assignment 0.Introduction This report provides a guidance for fire safety aspects that has to be followed in the designof Mr. and Mrs. Jones’s new house. Being the fire safety advisor for Mr. and Mrs. Jones , I intend to provide the fire safety standards according to modern Building Regulations , demanded by the building planning authorities. This fire safety report details the type of fire safety facilities that are planned to be incorporated in this house along with their specifications. This report has been prepared based on the guidance laid by Approved Document B ( Fire Safety ) – Volume 1 : Dwelling Houses ( 2006 ) edition. The report provides a combination of the aspects related to provisions for warning and escape , internal fire spread and external fire spread , facilities to fire service in the event of fire. These aspects are discussed in accordance to the map or drawing of the proposed new house. 2.0.Means of warning and Escape : The construction of the house has to be done such that in the event of fire , people can escape to a place of safety outside the house at all times without any obstacle. This involves giving proper and early warning to the residents about the fire incidence , safe routes of sufficient capacity which enable the residents to escape easily , the routes being fire resistant and easily accessible. These warning and escape strategies for this house are described as follows . 2.1. Fire detection and fire alarm systems : The new house is proposed to have sufficient number of smoke alarms and automatic fire detection systems according to British Standards – BS – 5839 – 6 : 2004 . The following discussion gives the positional design of these fire detection and warning systems . Smoke detector alarms have to be installed in the circulation space between kitchen and lounge in the ground floor and in the entrance of bedroom 3 – near roof access area in the first floor . Instead of ionization chamber smoke detectors , optical ( photo – electric ) smoke detectors are recommended because optical smoke detectors can distinguish invisible small particles of kitchen fumes from fire flames. This reduces the chances of false alarms. The recommended specifications for these optical smoke alarm are to be schottky diode in base , 15 – 30 V operating DC , around 60μA stand by current at around 22 V DC , magnetic testing facility and with level of protection as LP – 40 . An additional interlinked heat detector or alarm has been proposed for the kitchen , the specification of these include a Thermistor sensor with sensing range of 50 degree C to 70 degree C , operating voltage - 230 V at 50 – 60 hz , alkaline battery backup , solid state indicator lights , 85 dB at 3 m alarm sound level . Additional alarms placed in study room of ground floor and master bedroom of first floor must be interconnected so that the activation of one alarm activates the other alarms also. These can be wall mounting or ceiling mountable. The sensors of the smoke alarm have to be between 25 mm and 600 mm below the ceiling and the sensors of heat alarm are to be between at 25 mm to 150 mm below the ceiling . These detectors and alarms are to be mains - power connected , but they are also recommended to have standby power supplies. Flame proof manual call points with breakable front plate made of glass or plastic are recommended to be positioned in the hall near the stairs to alert the residents . 2.2.Means of Escape : This is a one storey house that does not require complex design of escape routes. The escape route is generally designed based on the population density or occupant capacity of the building , travel distance and escape capacity of the designed escape route . In the ground floor , Egress window of 450 mm x 450 mm and of area of at least 0.33 m2 , has to be provided in right side of the lounge room , which is an inner room as shown in the map . Occupants of kitchen can exit via the rear French door , people in study room and dining room can exit via the entrance door. For the first floor , one of the escape routes can be the stairs which has travel distances of less than 9 m from the master bed room , bed room 3 and bed room 5 . The other escape route is recommended to be an external escape stair planned in the rear side of the building in bed room 4. This escape route will have a travel distance of less than 9 m for the occupants of the dressing room, bed room 4 and bed room 2 . These room are sure to have very less occupant capacity . The doors leading to this route are to be of fire resistive material and the direction of open should be in the direction of passage. The design of this alternate external escape route along the rear side is valid as it encompasses an external envelope of 1800 mm . The materials used in this route should include fire resistive materials of European class A 1 materials. Automatic water sprinklers are proposed to be placed in the kitchen and bedrooms. The recommended specifications for these sprinklers are according to BAFSA ( 2006 ) , they are the maximum design temperature being 65 degree C and the maximum pressure being 12.1 bar . 3.0. Internal fire spread : The internal fire spread can be due to fire spread through lining or fire spread through the structure . 3.1. Internal fire spread ( Lining ) : These fire spread are based on the materials used for lining . To ensure fire safety from internal fire spread through lining , the following are recommended to Mr. and Mrs. Jones. The wall and ceiling linings are to be D s3 – d2 European class for the bedrooms and lounge , C s3 – d2 for other rooms and class B for circulatory area and escape routes. Thermoplastic material glazing for external windows in rooms . The lighting diffusers should not be thermoplastic in nature. Roof lights to rooms and circulation area can be of TP(a) classification . The roof lights of thermoplastic materials should not be part of the fire resistive ceiling , they should be suspended . 3.2 . Internal fire spread ( structure ) : The fire spread through the structure affects the stability of the building structure. The spread of fire through the structure has to be controlled by using fire resistive materials for the structure and by using automatic fire suppression systems. Also the construction must ensure that there is no unexpected spread of fire along the concealed spaces within the structure. For the proposed new house the following are the recommendations to avoid internal fire spread through structure . The elements of the structure like beams , columns, frames, load bearing walls , etc must be of non combustible material. Class 0 and Class 1 materials of the British standards like glass reinforced polyesters , block boards , metal fibre tiles , sheets with cement binding or sheets with resin binding are recommended . Roof construction is planned to be of B roof t4 classification , in accordance with BS EN – 13501 : 5 ( 2005 ) . The recommended materials must have 30 minute standard of fire resistance. Compartmentation of the first floor from the ground floor is recommended , as compartmentation helps in reducing the chances of the fire becoming large. For this double skinned insulated roof sheeting with non combustible material has been advised. To prevent the spread of smoke and flame through cavities , cavity barriers are advised to be used expect for the places that have double skinned insulated roof sheeting. Fire protecting elements should be used to prevent fire spread through openings of pipes. The pipes are recommended to be of lead , aluminium alloy , fibre cement material. 4.0. External Fire Spread : The construction of the external walls and roofing has to ensure that there is less risk of fire spread form any external ignition source. Also the unprotected area along the sides of the building have to be thermally isolated well from nearby buildings so as to reduce the incidents of external fire spread. The following are the recommendations for this house to prevent external fire spread. The materials fro the construction of external walls has to be better than Class B – s3 , d2 European class. Avoid combustible mountings on the external wall , even though the wall is fire resistive . Provision of sprinkler systems throughout the house to reduce the intensity and amount of fire spread. External boundaries or notional boundaries are advised to be at least 1000 mm from the wall. Based on the maximum unprotected area along the sides as seen in side elevation in map , the relevant boundary has to be at least 2.5 m from the building. According to the unprotected area in the rear wall , the relevant boundary has to be at least 7.5 m from the rear side wall. 5.0. Access and facilities provided to the Fire service : The construction of the building has to ensure the ability to access the building by fire personnel and fire appliances. The provision for fire service must include the following Vehicle access for pump appliances has to be at least 45 m from all points of the house. Turning facilities near dead ends for routes more than 20 long has to pre planned. Since fire appliances have no standards regarding the size and weight , consultation with fire and rescue authorities and local building control body has to be done to adopt the facilities related to fire service. Internal fire mains and related facilities have to be placed both in ground floor and first floor to assist the fire service personnel in their search and rescue operations. External ladders have to be placed in the sides to enable rescue operation via the egress windows. hydrants and water or foam based fire extinguishers have to be placed inside the house to assist the fire rescue operations . 6.0. General Fire Safety Considerations : Even with all considerations for fire safety mechanisms fire accidents may be incident. To save life and property during fire , there has to be a regular checking practice for the proper functioning of the fire detection and warning systems. Routine checking of the escape routes, escape route lightings , fire fighting equipments , fire warning systems . Information and instruction to the residents about fire escape routes is a pre requisite as stated by Regulatory Reform ( 2005 ) . The fire fighting equipments like extinguishers need to be handled according to the operating instructions prescribed by Manual Handling Operations Regulations ( 1992 ) . Removing dangerous substances also leads to less fire accidents as quoted by HSE books ( 2003 ) . 7.0.Conclusion : As a fire safety advisor , I have formulated the above said fire safety facilities for the new house of Mr. and Mrs. Jones . These safety standards are based on the map for the new house and are also complaint with the building regulations. The fire safety aspects related to detection and warning systems , fire spread , access by fire service personnel have been discussed relative to the design of this house. Also some general guidelines for fire safety has been outlined which could help the residents in managing fire accidents. 8.0. References : BS EN – 13501 : 5 , 2005 . Fire Classification of construction products and building materials - Classification using data from external fire exposure to roof tests. BS 9251 : 2005 , Sprinkler Systems for residential and Domestic occupancies - Code of practice. Dangerous Substances and Explosive Atmospheres Regulations 2002. Approved code of practice and guidance, L138. HSE Books, 2003. ISBN 0 7176 2203 7. Manual Handling Operations Regulations 1992, SI 1992/2793. The Stationery Office, 1992. ISBN 0 11 025920 3. Regulatory Reform ( Fire Safety ) Order 2005. Sprinklers for Safety , 2006 , Use and Benefits of incorporating sprinklers in buildings and structures . 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