CONSTRUCTION SITE FIRE SAFETY MANAGEMENT

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1 practice note 1/16 Shaping and sharing good practice in design & construction health and safety risk management APRIL 16 SITE FIRE SAFETY MANAGEMENT 1.0 SUMMARY Fires on construction sites have for many years been recognised as a serious problem for insurers and construction companies, but less of an issue from a public safety perspective as there are relatively few fire deaths in such incidents. Despite this, the HSE has issued clear requirements for fire safe management on sites within the Construction (Design and Management) Regulations 2015 and also in a guidance document HSG168. The trend to ever-taller buildings outside the UK has resulted in a number of significant fires during construction that have caused deaths and demonstrated the difficulties facing the fire service when tackling such incidents. On several occasions helicopters have had to be used for fire suppression and rescue. Insurers have long had concerns about the potential for major loss on such projects, and the fires that have occurred have demonstrated that their concerns are well founded. These concerns have been translated into an insurance-driven document, the Joint Code 1, which is frequently imposed on large projects (> 5 million). 2.0 HAZARD AND RISK ASSESSMENT IN MANAGEMENT It is the ever-changing nature of construction projects that presents the greatest risk. It is certainly true that in the early days of most construction projects there is little risk of fire. Site formation, piling, foundations and concrete pouring are all relatively low risk activities from a fire safety perspective. However, experience proves that even at this stage fires can and do occur. Timber shuttering burns extremely well; membranes used in damp proofing (and their adhesives) are also combustible and materials are delivered to site in disposable packaging that is also combustible. Modern methods of construction such as slip and jump forming utilise timber formwork and large volumes of (usually) flammable hydraulic liquid pressurised by diesel-powered compressors or generators. From an insurance perspective, construction projects also present a unique challenge because of the difficulties of assessing the risks, taking into account the changing nature of the work site activity and the ever-increasing financial exposure that will obviously rise as a project approaches completion. It has been said that the fire risk in most buildings is static while the risks on construction sites must be dynamic. 1 Fire Prevention on Construction Sites: The Joint Code of Practice on the Protection from Fire of Construction Sites and Buildings Undergoing Renovation: Ninth Edition October Published by the Fire Protection Association ISSN X

2 2.0 HAZARD AND RISK ASSESSMENT IN MANAGEMENT continued The following table demonstrates the sort of risk levels that might exist in a typical tall building on a 36-month construction programme: Months Site Activity Fire Risk Level Sum Insured 0-6 Site formation, foundations, piling Low 20% of total project 6-24 Tower construction/slip forming Moderate 50% of total project Cladding and services Moderate - High 65% of total project Internal fit out High 100% of total project Clearly, in the example above, any fire taking place after, say, month 24, is more likely to result in a major loss than a fire before then. Fires after the installation of cladding begins are going to present a much greater probability of serious damage as smoke and heat will be contained within the structure rather than being quickly vented. Large accumulations of combustible foam packing material must be removed from inside buildings under construction at the earliest opportunity. Factors that can affect the size of a loss that should be considered in respect of tall buildings are: Exceptional costs for prestige elements of construction such as marble and stone Availability of purpose-built systems such as elevators, escalators and external cladding Specialist materials such as membranes (e.g. the sail of the Burj al Arab hotel) Applicability of local building codes Expertise and availability of contractors Very short construction periods High standards of fixtures and fittings in prestige buildings 3.0 CAUSES OF FIRES ON SITES Fires will arise on all construction sites from time to time, and it is a measure of the success or otherwise of the fire safety management programme that damage will be restricted to small areas, there will be no impact on the programme and that no one will be injured or killed. Causes of construction site fires can be summarised as: Electrical Hot work Cooking Smoking Rubbish burning Overheating plant/equipment Escapes of gases or flammable liquids Arson/wilful fire setting All of these types/causes are well recognised and should be amenable to normal fire safety measures. Evidence of smoking on site except where permitted must be acted on in this case, its clear that there is ample easily ignitable waste nearby. It is perhaps a surprise for many people to learn that a significant percentage of fires in construction are deliberate possibly as much as 50%. Deliberately set fires are normally the result of intrusions to sites at night for various purposes, including by children and adolescents. The best protection against such attacks is good security.

3 3.0 CAUSES OF FIRES ON SITES continued The Joint Code now contains specific advice on site security including a requirement for this and for the risks of and from arson to be considered as part of the site fire risk assessment. Particular attention should be paid to: Deterring trespassers by providing a secure perimeter Bringing forward permanent security features as early as possible Where the building envelope forms the site perimeter, stopping up access points Providing an internal secure area for flammable liquids and gases Illuminating the site and its perimeters Utilising security personnel Providing monitored cctv Providing intruder alarm systems in temporary buildings Because of the additional risks involved in the construction of timber framed buildings some of these measures may be insurance requirements and in the case of sites utilising timber frame construction will usually be imposed as a Warranty. 4.0 CODES AND STANDARDS The primary legislation is, of course, the Construction (Design and Management) Regulations Guidance to the Regulations is provided in a separate document, Managing health and safety in construction (L153) which does not have the status of an ACOP. The relevant sections dealing with fire safety matters are contained in Regulations 29 32: Regulation 29 requires that suitable and sufficient steps be taken to prevents injuries from, inter alia, fire. Regulation 30 requires the establishment of procedures to be established to provide for a suitable response to emergency situations and for these to be notified to persons at work and for tests of the procedures to take place. Regulation 31 requires the provision of routes and exits to enable the safe evacuation of a site. Regulation 32 requires the provision of fire fighting equipment and fire detection and alarm systems. It should be remembered that, as for most UK fire and safety legislation, only the safety of people is mandated. As a result of this, the UK insurance market has produced its own rules to require measures to reduce the costs and impact of fire damage on construction sites. Improper use of two pin appliances must be prevented. The UK insurers collaborated with the UK construction industry and the Contractors Legal group and others to produce the first version of the Joint Code of Practice on the Protection from Fire of Construction Sites and Buildings Undergoing Renovation in May 1992.

4 4.0 CODES AND STANDARDS continued Gas bottles and their hose connections must be checked before use. The Code is currently in its ninth edition 2 dated October 2015 and covers the following: Design/Pre-Construction Phase Construction Phase Liaison with the emergency services Emergency procedures Fire protection Temporary protective covering materials Portable fire extinguishers Site security against arson Temporary buildings Site storage of flammable liquids and gases Electricity and gas Hot work Waste materials Plant and vehicles Stored materials Smoking High rise construction sites Large timber framed structures Despite the widespread use of the Joint Code (often as a Warranty), individual insurers may still issue specific requirements as Endorsements to policies. For example, the Munich Reinsurance Company s Endorsement No.112 Special conditions concerning fire fighting facilities and fire safety on construction sites contains the following specific requirement: adequate fire fighting equipment and sufficient extinguishing agents are available and operative at all times... Fully operative wet riser hydrants are installed up to one level below the highest current work level. This goes much further than the Joint Code (where there has been no substantive change in the requirements for site fire protection since the first edition) which asks for no more than the project designers to ensure, so far as reasonably practicable the early installation and operation of the building s fire protection systems. Indeed, some authorities having jurisdiction 3 have recently gone further than the Joint Code or any insurer by demanding that where basements of buildings under construction are to be utilised as temporary storage areas or site offices then either the permanent sprinkler system and fire hose reel system should be activated or a temporary sprinkler and hose reel system should be installed and activated 4. It is essential that all parts of a temporary electrical supply are properly maintained. An alternative to the UK Joint Code is the US code NFPA 241:2013 Standard for Safeguarding Construction, Alteration and Demolition. 2 Particular care has been taken to keep the terms used in the Joint Code consistent with those used in legislation and in respect of the 9th edition; amendments have been made to address the roles of the designer, contractor, principal designed and principal contractor. Reference to the CDM Coordinator has been removed. 3 For example, Building Code Departments. 4 Government of Dubai: Dubai Technology and Media Free Zone Authority: Circular 118: Fire Prevention at Construction Sites in Basement Area, 23 October The authority imposes financial sanctions on contractors who breach its Codes and has the power to close down construction sites where there is evidence of poor safety practices.

5 5.0 GENERAL FIRE SAFETY PRECAUTIONS DURING WORK High value equipment should be protected by certificated low combustibility sheet not plywood and tarpaulins. Other important fire safety precautions include: Minimising the storage of materials on site and prohibition of the storage of all combustible construction materials in the building Induction training for all site personnel and contractor operatives on the first day of work and not less than three-monthly thereafter Ensuring that escape and exit routes are clearly signed and that the signs are updated as construction develops Undertaking test evacuations not less than three monthly and regularly testing other emergency plans A total prohibition on rubbish burning anywhere on site A total prohibition on smoking other than in designated areas away from the building under construction A requirement for all hot work to be subject to a formal, written permit system A prohibition on the installation of temporary structures inside the building under construction unless these are designated as fire resistant externally/internally Controls on the use and storage of flammable liquids and flammable and explosive gases. This should include a requirement for double skinned tanks for all liquid fuels used in generators and compressors. A prohibition on eating, cooking and sleeping in the structure under construction, although under some circumstances, it may be permissible to establish canteens subject to this being in areas where there is a working sprinkler system Additional measures during fit out to take account of increased levels of hazard 6.0 STORAGE OF MATERIALS While off-site storage space and transport can be expensive this is always to be preferred to on-site storage. While much of the material used for construction may not be easily combustible, the packaging protecting this usually is. Apart from cardboard and plastic sheet, do not overlook the contribution to the fuel load of pallets and cable drums on one site it was calculated that there was enough timber in a storage area for cables to generate a 7mW fire. On another location, two hundred electrical control cubicles were protected from transit damage by timber frames, thick plastic sheet and plastic tarpaulins. Not only would this packaging have provided fuel for a 3 4mW fire but the plastic materials would have generated huge volumes of acidic and toxic smoke which would have made the resultant fire damage even greater. 7.0 EXIT ROUTES AND EMERGENCY DRILLS The ever-changing patterns of construction work can mean that a main escape route via a staircase on Monday will not be available on Wednesday so signage of the highest quality is essential. Where mixed nationality work groups are concerned, attention should be paid to the possible confusion due to language problems. Where there is a major change in access or egress this should be communicated to contractors and their operatives formally (during daily or weekly meetings), by posters and informally (during toolbox talks or lunchtime safety briefings).

6 7.0 EXIT ROUTES AND EMERGENCY DRILLS continued Emergency procedures for the evacuation of casualties using cages (where required) should be practiced as often as fire evacuation drills. Don t overlook crane drivers needs. Fire drills should be properly managed, timed and supervised and, if possible, filmed. The local fire service and insurers should be invited to observe and a formal de-briefing or washup meeting held the same day. Guidance on the need for alternative means of escape is to be found in HSG168 between pages 33 and 41. In particular it is worth noting the parameters set out in the table below which cover the maximum travel distances that could be considered as a minimum standard. While not mandatory, failure to comply with the contents of the table has been deemed to be a noncompliance with Regulations 29 and 31. Recommended travel distances for safe means of escape (HSG 168) 8.0 REMOVAL OF RUBBISH Failure to comply with this requirement is perhaps the most commonly encountered hazard. Perhaps the only reasonable excuse for non-compliance is in very tall buildings where hoist access is finite and may be restricted. One solution to this problem is to permit the limited accumulation of waste in certain specified areas on specified floors and for a contractor to be tasked to remove the waste when hoists are less in demand, usually at night. On most sites there can be no excuse for waste accumulations when all that is needed is the presence of skips. If these fill up quickly then either more skips are required or the skips need to be cleared more frequently. Accumulations of combustible waste suggest that skips needed to be emptied more frequently.

7 9.0 SMOKING Regardless of any other legal requirement, smoking should be banned in all construction areas and only where permitted by law, restricted to designated areas. The author is often told that this is a counsel of perfection and impossible to achieve. Experience these days suggests this is not so and all that is required is the will to enforce by dismissal of offenders, regardless of grade or status. On one major site more than 50 personnel were permanently barred from the site for contravention of this rule, including eight engineers/managers. Smoking must be prohibited on all sites even if there is a fire extinguisher nearby! 10.0 HOT WORK CONTROLS Formal compliance with a hot work permit system is the foundation of good construction fire safety management. Permits using multiple languages if necessary should be issued on a daily basis to named individuals only for specified operations There should be a presumption that all hot work should be undertaken in the presence of a suitably equipped and trained firewatch Adequate resources should be provided to allow for spot checks on permitholders during the working day by safety officers or inspectors Part of the permit process should be an inspection of the equipment to be used to verify that it is in good condition and fitted with the appropriate safety features (such as flash-back arrestors on gas welding equipment) 11.0 TEMPORARY STRUCTURES Very specific precautions must be in place in respect of temporary accommodation units, other such structures and site buildings. No temporary structure should be located inside or within 6m of the building under construction. Any temporary structure within 10m of the building under construction must have at least 30 minutes fire resistance. All temporary structures larger than 200m 2 in area should be fitted with an automatic fire detection and alarm system monitored 24/7. All enclosed canteen buildings or spaces must be fitted with an automatic fire detection and alarm system monitored 24/7. Any equipment used for deep fat frying should not be permitted unless it is protected by an automatic wet chemical fire suppression system. Where temporary accommodation units are stacked, then these must comply with the Building Regulations / Scottish Building Standards. This will usually mean the provision of an alternate escape route, fire detection and alarm system, exit signs, emergency lighting and portable fire extinguishers.

8 12.0 FLAMMABLE GASES Consideration should be given to restricting or even banning the use of oxy-acetylene in favour of other equipment such as oxy-propane. If this gas is really essential, it should be possible to set up a procedure to ensure that acetylene is brought to site for that work only and removed at the end of every working day. Segregated storage of combustible gases by type and also full/empty condition should be imposed and all such enclosures located away from the building under construction FLAMMABLE LIQUIDS Centralised generation of construction power (where this is necessary) should be preferred to the use of many small generators and compressors. There should also be strict control of plastic cans for storing fuel for power tools. All diesel generating plant should be supplied with fuel from double skinned tanks and resupply of fuel to all plant including mobile plant must be strictly controlled and precautions taken to minimise spills or refueling engines which are running. No refueling of plant should be permitted within 10m of the building under construction or 20m of a timber-framed structure. Bulk flammable liquids should be stored only in double skinned tanks or in suitable bunded structures which will contain 110% of the total capacity of fuel stored FIRE FIGHTING The need for first aid fire-fighting on any construction site will be obvious. The larger the site, the greater the need for an organised fire team. The lack of compartmentation, water supplies, fire detection and fire suppression systems mean that any fire on a site risks significant damage and impact on the programme. The later the stage of construction, the greater the risk to the project and the higher cost of damage. The provision of portable fire equipment throughout the site in clearly marked fire points is essential as is a temporary fire water supply. On all structures taller than two storeys or of an area of more than 1000m 2, a pressurised temporary water supply should be provided with a stored volume of not less than 300m 3. Changes in status of areas or equipment should be clearly signed. In urban areas where there is a municipal fire water supply through hydrants, this volume may be reduced by half. In remote locations or construction sites where the municipal fire service has a response time of more than 30 minutes or where standards of fire cover are questionable then the volume of water stored should be not less than 500m 3 and a firefighting vehicle fitted with a tank containing not less than 2000 litres of water, a pump of capacity not less than 900 litres per minute at 5 bar and appropriate quantities of hose and other equipment could be usefully provided on site. Appropriate training should be provided to appropriate site personnel, including security guards. Where buildings are taller than three storeys or 20m then a wet riser should be installed to supply a hose reel on each floor below the floor under construction. The hose should be of diameter not less than 19mm and should reach within 3m of all parts of the floor with a throw of not less than 3m at a pressure of not less than 3 bar but not more than 5 bar. A structured programme of maintenance of all fire equipment will be put in place before any work starts on site.

9 15.0 FITTING OUT Probably the most dangerous part of a construction project takes place when cladding is complete and fitting out begins, but before fire compartmentation or fire detection and suppression systems are operational. During this period, it is the practice of trying to prevent damage to finished areas that can generate high levels of hazard. The Joint Code, since its second edition, has drawn attention to the risks of the materials often used to protect finished surfaces, fittings etc. Where ad hoc materials such as plywood, plastic sheeting and tarpaulins are utilised for these purposes, this increases the fuel load in the building and also creates the possibility of large volumes of toxic, acidic smoke generation. This can be prevented by ensuring that all fit-out contracts contain requirements for all protective cladding, including scaffolding sheeting, to be either noncombustible or to comply with LPS 1207 Fire Requirements for Protective Covering Materials 5 or LPS 1215 Flammability Requirements and tests for LPCB Approval of Scaffolding Materials. Protection of high value, long lead time items with fire rated ply and listed low combustibility sheeting. Recently, some manufacturers are providing materials that comply with both LPS 1207 and LPS 1215, and are also robust and can be reused. Great care should be taken in the selection, induction and supervision of tenant fit-out contractors who should be subject to the same controls and standards of site safety/ management as all other personnel on site TIMBER FRAMED Following a number of serious fires in timber-framed buildings under construction, concerns were expressed by the Chief Fire Officers Association (CFOA), the Business and Community Safety Forum, and the Fire and Rescue Services Forum. This document, The Dangers of Fires in Timber Framed Construction 6, highlighted the following concerns specific to timber-framed buildings: The volume of timber used in the buildings created a hazard for both the construction workers and firefighters Timber-framed buildings are likely to be at their most hazardous during the early stages of construction where there is no active protection and probably very little passive fire protection Rapid fire spread, large amounts of heat and early structural collapse are all probable consequences of such fires Poor workmanship can contribute to rapid fire spread even in completed buildings In the longer term, there are concerns that wear and tear, poor maintenance and alterations (both professional and DIY ) will increase the risk of fire spread even in those structures where the original construction is good Partial occupancy could be a major life risk The use of timber-framed buildings for social housing will negate the conventional approaches to fire safety in dwellings such as early detection and defend in place compartmentation. 5 LPS: Loss Prevention Standard. Document issued by LPCB/BRE Certification Ltd. See: 6 Dated 2 April 2009, this can be accessed at:

10 17.0 TIMBER FRAMED continued These concerns have resulted in advice being generated by the HSE (in HSG168) and the insurers (in the Joint Code). Both documents suggest that where multiple timber-framed structures are being erected on a site, that the work be phased so as to minimize the risks of fire jumping from building to building. The Joint Code also requires that the measures to prevent deliberate fires in Section 12 of the Code must be adopted. Other measures to prevent fires should be considered including: Applying final cladding as soon as possible Keeping generators and similar equipment outside timber-framed structures Removing gas cylinders at the end of the working day and locating them 20m from the building under construction Ensuring that temporary buildings are located more than 20m from the timber-framed structure or alternatively, using only noncombustible temporary buildings Heating, dehumidifying and drying equipment should be restricted to 110v blown air type and removed from the structure outside working hours All electrical power other than that required for security or fire systems should be isolated at the end of the working day Automatic fire detection should be installed in enclosed spaces as the work progresses Additional measures should be taken to ensure that hot work is minimized and that which is essential is subject to strict control prior to closing the permit. Additional guidance may be obtained from the Timber Frame Association which provides a number of documents and DVDs 7. A temporary BS 9251 sprinkler system in this timber-framed building will protect it during construction. This is a reconstruction of a residential care home the original was totally destroyed during a fire which occurred during construction. Note also the radio-based fire detection sensor/sounder. 7

11 18.0 COMMISSIONING AND PART OCCUPATION Commissioning of a new building should not take place unless all of the building s fire protection systems are fully operational. Where this is not possible then exceptional precautions should be taken such as arranging for the municipal fire and rescue service to stand by on site. Part-occupation of buildings under construction is always going to be perceived as generating a significant increase in hazard and should always be subject to special conditions. Where this occupation involves basement levels, usually intended for car parking, the insurers and authority having jurisdiction are entitled to ask: Should a fire occur in this area, how will it be fought? If, as is normal in many jurisdictions, the basements are to be fitted with sprinklers and/ or smoke extraction equipment, what will happen to a fire when the fire systems are not operational? Given the well-known difficulties and dangers of fighting fires underground, is it reasonable to expect local fire brigades (perhaps poorly resourced) to risk the lives of their personnel under such circumstances? Temporary fire call point and sounder. Note proximity of completed building s call point ideally, this should be labelled as not in service. The Author Stewart Kidd is a loss prevention consultant and Chartered Security Professional with wide experience of managing construction site fire risks worldwide. He was the secretary to the working group that wrote the first edition of the Joint Code and is presently advising the insurers of the new Jeddah Airport. He was the insurance fire advisor on the Burj Khalifa, Dubai, Heathrow Terminal 2 and London Bridge Tower (the Shard). Loss Prevention Consultancy Ltd