External Cladding in High Rise Buildings in the Gulf Countries - Report Example

Please just send a message if you need anything. Thanks! External Cladding in High Rise Buildings in the Gulf Countries Table of Contents Contents Contents 2 1. Introduction Fighting fire in high-rise buildings is undoubtedly challenging particularly when the external cladding of a building greatly contributes to the spread of fire. The following sections discuss the effect of compartment and external cladding in fire safety, the risk and fire behaviour in external cladding, how external cladding is affected by both external and internal fire, fire fighting challenges in high-rise buildings, human sufferings caused by fire, international fire incidents involving external cladding, assumptions and scenarios of high-rise fire incidents in the Gulf region, and recommendations in the construction and maintenance of external cladding. 2. Effect of Compartmentation and External Cladding The fire in Summerland complex and old people’s home in Nottinghamshire in the early 1970s that killed 68 people change the way UK fire authorities view fire in the built environment. This is because inquiries of both events suggest that such disastrous events could not have happened if there was compartmentation and fire-proof external cladding to control fire spread (New Scientist, 1976, p.720). Today, compartmentation is an integral part of fire protection as it is generally seen as an effective solution to prevent fire spread by creating fire-resistant subdivisions (Ryan, 2011, p.285). Research on the effect of compartmentation suggest that people and property outside the compartment are protected and saved because movement of fire and smoke are delayed by the fire resistant walls enclosing the compartment (Stellman, 1998, p.41). According to the Society of Fire Protection Engineers (2002), is also an important element of fire protection strategy in high rise buildings as it provides occupants plenty of time to escape while fire fighting operations are taking place. Moreover, compartmentation is effective in controlling both horizontal and vertical fire spread, and protects occupants from heat and toxic smoke exposure (p.352). Since passive fire protection measures such as compartmentation divides a building into a series of fire and smoke tight areas, damage to property is limited to the part of the building where the fire started. Moreover, complete evacuation in compartmented buildings is often not necessary as occupants can take refuge outside the compartment while the fire is being extinguished (Stollard & Abraham, 1999, p.77). Insulation materials play an important role in the heating and cooling of a building as solar radiation affects the thermal performance of a building. Therefore, materials used in the walls and external cladding of high-rise structures determine its thermal performance from solar radiation as well as heat transfer from a nearby fire (Brebbia & Zubir, 2011, p. 220). According to Basbagill (2008), fire resistance is one of that main considerations in external cladding and materials used for this purpose such as ceramic stone, brick, metals, and others are not only considered for their exceptional resistance to water but to extreme temperatures from the sun and fire (p.25). Fire protection regulations often recommend safe distance from neighbouring buildings to prevent fire spread but if this recommended distance cannot be achieved, fire-resistant external walls is required (Kolb, 2008, p.303). Moreover, building materials according to Shaun (2007) lose their strength at elevated temperatures thus it is important to protect them from neighbouring fire (p.6). Generally, external cladding that is not more than 1 metre from a boundary should be built from non-combustible materials but in high-rise buildings where large number of floors and occupants may be affected, cladding materials reaction to fire is very important (Tricker, 2008, p.392). 3. Risk and behaviour of fire in the cladding Selecting materials for external cladding is vital for fire safety as cladding panels can create significant risk particularly when exposed to fire (Department of Health, 2007, p.4). According to LPCB (2012), the danger of installing combustible external cladding in multi-storey building is not entirely coming from neighbouring fire but from fire spreading from the lower floors through windows up to the external cladding system. For instance, when a fire breaks out on lower storey there is a tendency for fire to spread out of the window and travel along the external cladding and spread back through windows in the upper stories (p.1). Another danger is the fact that fire outside the built environment has unlimited supply of oxygen from air and will rapidly consume the external cladding system until it collapse and affects escaping occupants and fire fighters on the ground. This possibility is recognized by UK building regulation’s Approved Document B where it states that external cladding of buildings with 18m or more must be of limited combustibility. Similarly, BS 8414 recognized that external cladding of modern buildings constructed with lower environmental impacts in mind is combustible and therefore must be comply and pass the fire performance test (LPCBM 2012, p.2). According to Ruxandra (2012), fire behaviour is dependent on the ignitability and burning properties of external cladding materials. For instance, the shape of fire plume outside the building and upward flame spread are influenced not only by the window openings, external temperature, wind speed rate, and pressure but thermal properties of the external cladding system (p.2). Moreover, fire spread is not limited to combustible external claddings as there a number of serious fire spread involving non-combustible claddings as in the case of First Interstate Bank fire in the United States where flames and hot gases passed through the gap between the floor slab and exterior cladding. Another is external fire spread that started from the lower floor up to the 24th floor of the 31-storey Andraus Building in San Paolo Brazil in 1972 (Bong, 2000, p.28). According to Bong (2000), there are three mechanisms involved in external cladding fires. First, external cladding may be severely affected by convective and radiant heat fluxes generated by a window fire plume. Second is the absence of vertical and horizontal projections to control fire spread as a result of window fire plume as shown in Figure 2. Third is the combustibility of the external cladding materials (p.13). Figure 1- Example of external fire spread from lower to upper floor (Bong, 2000) Figure 2- Vertical and Horizontal projection to reduce vertical fire spread (Bong, 2000) The fire that engulfed the 34-storey Tamweel Tower in Dubai started on the ground floor but it went up to the roof which witnesses says spread and cannot be controlled because of the building’s combustible cladding as shown below. Note the debris of the external cladding on the ground. Figure 3- Tamweel Tower in Dubai (Jandaly & De Leon, 2012) Another fire involving external cladding is the Al Nasser Towers in Doha Qatar which in 2006 was reported burning due to use of banned combustible cladding materials (Press Trust of India, 20006, p.1). Note the flames coming out the windows and burning cladding. Figure 4= The burning Al Nasser Tower in 2006 (Gulf News, 2006) A high-rise residential building was also engulfed by fire that started on the first floor and spread to the upper floor last April 2012. Although nobody was injured, the 43-storey Sharjah’s Al Tayer Tower fire took 5 hours to control as the flames spread outside the building through the external cladding as shown below (Yu, 2012, p.1). Note how the fire consumes the external parts of the building in the left image and how fire fighters in the second picture were unable to reach the upper floors. Figure 5- The Sharjah’s Al Tayer Tower Fire (Yu, 2012) Similarly, the Al Baker Tower in Sharja was also consumed by fire in 2012 that started in Room 101 of the first floor. Police report suggest that fire spread rapidly and consumed half of the tower because of wind speed and external cladding made of combustible materials (CW Staff, 2012, p.1). Figure 6 - Al Baker Tower (CW Staff, 2012) 4. Challenges in extinguishing fire in high rise buildings Fire fighting in modern steel-framed high-rise buildings according to Craighead (2009) and International Association of Fire Chiefs (2008) is different and challenging because this type of building resembles a stack of individual floor compartments connected by stairways, elevator shafts, and other vertical passages which is difficult to ventilate. Another is the fact that most high-rise buildings have sealed windows that are almost unbreakable and smoke movement in high-rise buildings have unique patterns as they can be trapped on a certain floor or move up or down and within using the vertical shafts. High-rise buildings with HVAC systems but with no smoke management capabilities may circulate smoke in different parts of the buildings rather than exhausting them directly to the outside. Stack effect can also occur in high-rise buildings particularly when the interior temperature is higher than outside temperature. The difference in temperature can generate stack effect that will cause smoke to rise rapidly into the upper floors through stairways, elevator shafts, and others (p.49; p.434). Although most high-rise buildings are equipped with different fire protection systems, this is not a guarantee for effective and safe fire fighting as improper maintenance of these system can lead to disaster. According to the International Association of Fire Chiefs (2011), three fire fighters died and a number of floors were burned in the multi-storey One Meridian Plaza in Philadelphia US, because fire fighters cannot obtain sufficient pressure from incorrectly set pressure-reducing valves on the standpipe system (p.656). High-rise buildings present new and different problems particularly in extinguishing the fire and occupants safety. According to Stellman (1998), elevators are common in high-rise buildings but in terms of fire, they are unsafe for the following reasons. For instance, occupants escaping from fire may lose valuable escape time because they have to wait for the elevator. Another is the inability of the elevator to start due to elevators doors blocked panicking crowd. More importantly, escaping people may be trapped due to power failure during a fire (p.41). In terms of fire fighting, fire fighters may find it difficult to fight fires in high-rise buildings as standard fire fighting equipment can only reach up seven stories. Most high-rise buildings only have two exit stairways that can lengthen evacuation time by around two hours in a fifty-story building. Moreover, fire fighters must be able to climb up through the stairs where occupants from the upper floor may be descending or encounter occupants re-entering the stairway to rescue their family or save valuables. Lastly, since high-rise buildings are so tall, most occupants are hesitant to evacuate because they rather trust fire fighters than walking down the stairs (Binggelli, 2009, p.346). 5. Consequences of fire incidents in high-rise buildings Fires generally result to extreme human suffering and economic losses (National Research Council, 2003, p.3). Summary of notable high-rise building incidents from 1974 to 2009 as shown below suggest that fires in this type of building is not only materially destructive but emotionally depressing. Note that those killed in One Meridian Plaza were fire fighters. Figure 7= Summarized High-Rise building fires and their consequences (Fennelly, 2001) Aside from the direct consequences of high-rise building fires, the human cost is financially incalculable as it kills and injured so many people. Majority of causalities suffered suffocation from smoke and toxic gases and burn caused by excessive heat (Irvine et al, 1999, p.383). Note that the intensity of human sufferings from high-rise buildings and single-storey buildings are similar but the ordeal of people caught in high-rise building fire may be greater. For instance, they were reports that people jumped from the World Trade Centre to escape the blazing fire. Moreover, human sufferings are not limited to those affected by fire but to relatives of those who were killed and injured by fire. For instance, the death of three fire fighters in One Meridean Plaza probably results to extreme sufferings of their families. 6. Assumptions and Possible Scenarios for fire accidents in the Gulf region- Dubai, Sharja, and Qatar Wind speed is one major factor that may increase the intensity of high-rise building fires in the Gulf region. Another is the continuous use of banned construction materials for external cladding which as mentioned earlier were used in Al Nasser and Al Baker Towers. Although these high-rise buildings fires did not kill anybody, the displacement of considerable number of people from their homes is equally depressing. However, since the government is aware of the consequences of fire, accidents in this region may be reduced but if high-rise building’s external cladding will be constructed of the same materials and fire safety equipment is not upgraded for this type of building, then result of fire accidents may be greater in the future. Moreover, possible scenarios of fire accidents in the region may be extreme considering the continuous construction of higher towers and use of eco-friendly construction materials particularly in exterior walls. 7. Recommended construction and maintenance of combustible cladding As discussed in Section 3, the risk and fire behaviour in cladding depends on the quality of construction and materials used in cladding. For this reason, this report recommends that fire safety be considered during cladding installation. For instance, consider flames coming out of the window, gap between wall and cladding, vertical and horizontal projection, and use of fire resistance cladding materials. Maintenance should include checking gaps, contamination and deterioration of cladding materials. 8. Summary/Conclusion In general, use of combustible materials for external cladding should be avoided as flames coming out of windows may travel through the burning external cladding and spread in the upper floors. If use of environmental friendly materials is unavoidable, then it should be constructed with fire safety measures in mind such as vertical and horizontal projection, and non-combustible covering particularly above windows. The resulting human consequences of high-rise building is unimaginable thus building owner’s priority must be human safety instead of grandeur and decoration. Finally, challenges in extinguishing fire and evacuating people in high-rise buildings must be met by the fire authorities through upgrade and personnel development. 9. References Basbagill J, (2008), Fibre Reinforced Phenolic Foam, University of Southern California, ProQuest, US Bingelli C, (2009), Building Systems for Interior Designers, John Wiley & Sons, US Bong F, (2000), Fire Spread on Exterior Walls, Fire Engineering Research Report 2000/1, pp. 1 - 159 Brebbia C. & Zubir S, (2011), Management of Natural Resources, Sustainable Development and Ecological Hazards III, WIT Press, US Craighead G, (2009), High-Rise Security and Fire Life Safety, Butterworth-Heinemann, UK CW Staff, (2012), Sharjah Al Baker Tower Fire caused by cigarette, Construction Week Online, available online at http://www.constructionweekonline.com/article-16634-sharjah-al-baker-tower-fire-caused-by-cigarette/#.UP27Px3rxwF Department of Health, (2007), Firecode – Fire Safety in the NHS, Stationery Office, UK Fennelly L, (2012), Handbook of Loss Prevention and Crime Prevention, Elsevier, UK International Association of Fire Chiefs, (2008), Fundamentals of Fire Fighter Skills, Jones & Bartlett Learning, UK International Association of Fire Chiefs, (2011), Fundamentals of Fire Fighter Skills, Jones & Bartlett, UK Irvine D, McCluskey, & Robinson I, (2000), Fire hazards and some common polymers, Journal of Polymer Degradation and Stability, 67 (2000), pp.383-396 Jandally A. & De Leon J, (2012), Cigarette but caused Tamweel Tower Fire, Gulf News, available online at http://gulfnews.com/news/gulf/uae/emergencies/cigarette-butt-caused-tamweel-tower-fire-1.1114231 Kolb J, (2008), Systems in Timber Engineering: Load bearing structures and component layers, Springer, Germany LPCB, (2012), The Dangers of External Cladding Fires in Multi-Storey Buildings, LPCB News, pp. 1-3 National Research Council, (2003), Making the Nation Safe from Fire: A Path Forward Research, National Academies Press, US New Scientist, (1976), The Ghost of the Past in the New Building Regulations, Reed Business Information, US Press Trust of India, (2006), Al Nasr Towers in Doha again gutted, Hindustan Times, available online at http://www.hindustantimes.com/News-Feed/NM11/Al-Nasr-Towers-in-Doha-again-gutted/Article1-102900.aspx Ryan C, (2011), Traditional Construction for a Sustainable Future, Taylor & Francis, UK Ruxandra D, (2012), Sustainable Fire Safety Design for Building Frontages, Journal of Applied Engineering Sciences, Volume 2 (15), pp. 19-24 Shaun A, (2007), Health and Safety Accidents and the Causes Analysis within the Construction Industry, Lulu.com , US Stellman J, (1998), Encyclopaedia of Occupational Health and Safety, International Labour Organization, US Stollard P. & Abrahams J, (1999), Fire from First Principles: A Design Guide to Building Fire Safety, Taylor & Francis, UK Tricker R. & Algar R, (2008), Scottish Building Standards in Brief, Routledge, UK Yu P, (2012) Fire breaks out at Sharjah Tower, Gulf News, available online at http://gulfnews.com/news/gulf/uae/emergencies/fire-breaks-out-at-sharjah-tower-1.1014750 Read More

Since passive fire protection measures such as compartmentation divides a building into a series of fire and smoke tight areas, damage to property is limited to the part of the building where the fire started. Moreover, complete evacuation in compartmented buildings is often not necessary as occupants can take refuge outside the compartment while the fire is being extinguished (Stollard & Abraham, 1999, p.77). Insulation materials play an important role in the heating and cooling of a building as solar radiation affects the thermal performance of a building.

Therefore, materials used in the walls and external cladding of high-rise structures determine its thermal performance from solar radiation as well as heat transfer from a nearby fire (Brebbia & Zubir, 2011, p. 220). According to Basbagill (2008), fire resistance is one of that main considerations in external cladding and materials used for this purpose such as ceramic stone, brick, metals, and others are not only considered for their exceptional resistance to water but to extreme temperatures from the sun and fire (p.25). Fire protection regulations often recommend safe distance from neighbouring buildings to prevent fire spread but if this recommended distance cannot be achieved, fire-resistant external walls is required (Kolb, 2008, p.303). Moreover, building materials according to Shaun (2007) lose their strength at elevated temperatures thus it is important to protect them from neighbouring fire (p.6). Generally, external cladding that is not more than 1 metre from a boundary should be built from non-combustible materials but in high-rise buildings where large number of floors and occupants may be affected, cladding materials reaction to fire is very important (Tricker, 2008, p.392). 3.

Risk and behaviour of fire in the cladding Selecting materials for external cladding is vital for fire safety as cladding panels can create significant risk particularly when exposed to fire (Department of Health, 2007, p.4). According to LPCB (2012), the danger of installing combustible external cladding in multi-storey building is not entirely coming from neighbouring fire but from fire spreading from the lower floors through windows up to the external cladding system. For instance, when a fire breaks out on lower storey there is a tendency for fire to spread out of the window and travel along the external cladding and spread back through windows in the upper stories (p.1). Another danger is the fact that fire outside the built environment has unlimited supply of oxygen from air and will rapidly consume the external cladding system until it collapse and affects escaping occupants and fire fighters on the ground.

This possibility is recognized by UK building regulation’s Approved Document B where it states that external cladding of buildings with 18m or more must be of limited combustibility. Similarly, BS 8414 recognized that external cladding of modern buildings constructed with lower environmental impacts in mind is combustible and therefore must be comply and pass the fire performance test (LPCBM 2012, p.2). According to Ruxandra (2012), fire behaviour is dependent on the ignitability and burning properties of external cladding materials.

For instance, the shape of fire plume outside the building and upward flame spread are influenced not only by the window openings, external temperature, wind speed rate, and pressure but thermal properties of the external cladding system (p.2). Moreover, fire spread is not limited to combustible external claddings as there a number of serious fire spread involving non-combustible claddings as in the case of First Interstate Bank fire in the United States where flames and hot gases passed through the gap between the floor slab and exterior cladding.

Another is external fire spread that started from the lower floor up to the 24th floor of the 31-storey Andraus Building in San Paolo Brazil in 1972 (Bong, 2000, p.28). According to Bong (2000), there are three mechanisms involved in external cladding fires.

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