FIRE SAFETY IN THE BUILT-ENVIRONMENT: A CASE STUDY IN A RESIDENTIAL FACILITY

Typically, the initiation of fire is the outcome of the interaction between three ingredients, namely, a heat source, a combustible material, and the availability of enough concentration of Oxygen in the ambient atmosphere. The readily availability of these three ingredients constitute the “fire triangle”, where the absence of one ingredient will hinder the occurrence of ignition [7].

Combustible materials in residential facilities is one of the parameters that should be controlled to reduce the advent of fire development and propagation. Previous studies were conducted to investigate the characteristics of combustible materials in residential facilities. Cooking oils and grease usually found in kitchens are the most critical combustible contents that are readily available in residential facilities. These combustibles can be easily ignite and produce extreme temperature [8, 9, 10]. Fabrics such as clothing, curtains, carpets, mattresses, bedding and upholstered furniture constitute also a significant amount for fire load, that is usually found through other spaces in residential facilities [3, 9]. Combustible wall and ceiling finishes, as well as decorative materials could also contribute to the development of fire in residential facilities [11].

The causes of fire ignition in residential facilities are numerous. It is essential to realize that the building spaces that accommodate high concentration of combustibles would facilitate the occurrence of ignition, in the availability of a source of heat. Generally, the most common source of fire ignition in residential buildings is heat. The heat could be present in different ways within residential buildings. Heat could be emitted from electrical equipment and installations, cooking and smoking [12]. The most common cause of residential fires is the cooking fire [3]. Cooking fires have led to major injuries as well as significant financial losses in many cases [9]. In most cooking fires, the ignition occurred due to the readily presence of cooking oil, which is highly ignitable, and could contribute rapidly to fire propagation [13]. Electrical equipment and installations are also a main cause of residential fires [9, 14, 15]. The fire could occur due to malfunctions, failures and lack of maintenance of electrical systems [3]. There are also other causes of fire in residential facilities. These causes are correlated with behavioral aspects such as smoking, playing with heat source, and heating [9].

Spaces containing sources of ignition as well as concentration of comestibles are considered to be areas of high potential to fire risk in a building. Designers and occupants of residential facilities need to reduce the potential for ignition in these areas. The kitchen is considered to be the riskiest space in term of its potential for the development of fire, due to the readily availability of both ingredients of the fire triangle, namely sources of heat from cooking devices, and combustibles such as oil and grease [10], as well as gas supplies for operating ovens. Therefore, cooking oil needs to be handled carefully, as well as stored properly [13]. Moreover, kitchens in residential facilities need to be adequately ventilated to mitigate the risk of fire, originating from gas supplies, as well as reducing the accumulation of heat. Bedrooms and living rooms are high risk areas to ignition in residential facilities, due to the availability of combustible materials in the form of fabrics such as cloths and furniture [10]. In addition, these spaces might include other electrical equipment that could ignite such as television sets and heaters [8].

The risk of residential fires is not only limited to the unit, or the building in which the fire has occurred. The fire might spread to neighboring structures, and hence, pose a risk to these structures due to the amount of heat being released. For example, the fire that occurred in an apartment building located in Holland Township, Michigan, in the United States has caused damages to the adjacent structures, due to the amount of heat emitted from the flames [16]. Another example is the fire that occurred in the 12-unit apartment building, located in Salt Lake City, Utah, in the United States. The fire was initiated in one of the units, then propagated to the roof in a rapid manner, prior to the arrival of the fire department. The fire has also posed a potential risk to the adjacent structures, and thus, the occupants of these structures were evacuated [17].

The building selected for the case study is an apartment building, located in Khobar, Saudi Arabia. Figures 1 and 2 illustrate the floor plan and elevation views of the case study building, respectively. The building is classified as “R-2” occupancy, according to the International Fire Code. The classification of “R-2” occupancy is used for categorizing facilities that are used for sleeping and accommodations, where the number of occupants exceeds 5 persons. The occupants are considered to be permanent in the facility, such as boarding houses, hotels (not transient), and apartments [6]. The building is 3 storey building, in addition to a basement used for car parking. It has been continuously occupied since May 2013. The area of each floor is 2,025 m². Each floor has 16 apartments, varying between 2-3 bedrooms. The building can accommodate 214 persons.

Figure 1.

Figure 2.

A copy of the as-built drawings of the building was obtained for the purpose of investigating the compliance of the building with the fire safety code requirements. The drawings also served to assess other dimensional measures such as the travel distances, and the locations of fire exits. The set of as-built drawings consisted of a site plan, floor plans, and layouts of the fire safety systems installed in the building.

An inspection checklist, based on the international fire safety code requirements [6], to assess the provision of fire safety measures in residential occupancies was developed. Identification of risks through the utilization of checklists is a recognized methodology for risk assessment. The development of checklists entail the itemization of measures or indicators to be verified as acceptable or adequate by code requirements [18]. The inspection checklist included 38 measures pertaining to the means of egress, fire protection systems, electrical installation and distribution systems, fire doors; housekeeping practices; hazardous materials and miscellaneous fire safety requirements. Table 1 illustrates the developed inspection checklist for assessing the provision of fire safety measures in the case study building.

The means of egress is defined as the continuous, unhindered path of departure from any location in the building to a refuge area, away from sources of hazards [19]. The walkthrough inspection of the means of egress revealed that most of the violations were related to the accessibility of the fire exits, absence of fire-rated doors, swinging in the direction of travel, and exceeded travel distances. The travel distance is the walking distance from a location, where a distress is found, to the nearest fire escape. Access to the assembly area outside the building was obstructed due to security barriers in the site. As the travel distance in R-2 occupancies, should not exceed 15 meters [6], random selection of two points in the building indicated that the travel distances were 27 and 34 meters, respectively, as indicated in Figure 1. Violations to the requirement of travel distance were noted in all three stories. Previous studies have empathized the role of compliance with travel distances with code requirements, due to their impact for occupant’s safety in case of emergencies [20, 21].

The walkthrough inspection was carried out to inspect the provision of fire extinguishers, sprinkler systems, fire alarm systems, and smoke/heat detection systems. The inspection revealed that fire extinguishers were distributed sufficiently in all typical floors according to the code requirements [6], while they were not adequately distributed in the ground floor, as well as the basement. However, extinguishers are replaced every six months by the service provider. The walkthrough inspection indicated that sprinkler systems were only installed in the basement, while code requirements [6] mandate that they should be installed in all floors. Fire alarm systems were sufficiently distributed throughout the building, likewise fire detection systems. Moreover, the inspection concluded that detection systems were adequately provided in kitchens. In several incidences, it has been reported that detection systems have contributed to the survival of occupants in fire accidents [22]. Figure 1 illustrates the locations of the placed fire extinguishers and installed fire alarm and detection systems.

The walkthrough inspection indicated that all fire safety requirements [6] as per the developed inspection checklist for electrical installation and distribution systems were satisfied. The walkthrough inspection also revealed the availability of a backup electrical supply to power the fire pump, the fire alarm system and the exit signs. This backup electrical supply is a strong necessity since the power supply maybe cut off the building during the fire incident, and hence the operation of the fire protection systems will be hindered due to the lack of power supply [23, 24].

Fire doors should be clearly identified through “Exit” signs. They should not also be obstructed in any manner, at all times, for the purpose of enabling the occupants to leave the building safely during emergencies [21]. The walkthrough inspection uncovered major violations in the provision of fire doors in the ground floor of the building. The available doors, while called “fire doors”, were manufactured out of aluminum frames and glass panels. The doors did not include any fire rated materials in their assembly. Further, it was observed that the each of the two installed two-panel doors have one of the panels fixed, which will lead to a reduced capacity of 50% in terms of door width. These two doors constitute the main doors for gaining entry to the building, as well as escaping from the building in the event of a fire emergency. This reduced capacity of these doors will form a challenge during the evacuation of occupants during the fire emergency. Additionally, these doors were not swinging in the egress direction.

Housekeeping is an activity that considers the provision of technical fire safety measures, as well as the social aspects pertaining to the occupants’ behavior, and its impact on safety [25]. The walkthrough inspection for housekeeping practices in the corridors between the apartment units revealed that the distribution of dumpsters and containers is adequate, according to code requirements [6]. An indoor inspection of a typical apartment unit indicated that the kitchen layout and the installation of the appliances within were in an appropriate level of safety. The apartment units were provided with electrical ovens, rather than gas-source type. Hence, the hazards that can contribute to ignition from gas supplies, are eliminated. A fire blanket was provided in each kitchen, and was mounted on the wall. Moreover, the occupants are well informed about the location of fire extinguishers, since there is one extinguisher available in front of each apartment’s door. Occupants are also well informed about the location of the fire hose cabinets, as well as the evacuation plan in each floor, since occupants will pass them through the corridors.

The walkthrough inspection indicated that all the criteria pertaining to the miscellaneous fire safety requirements were satisfactory, except that the building did not have clearly readable address number, being obvious from the street in front of the building, for ease of identification by the fire department in case of a fire emergency.

The walkthrough inspection of the case study building indicated that the building is free from high concentration of hazardous materials, as listed in the developed inspection checklist, that could easily ignite and contribute significantly to flame and smoke propagation. However, residential facilities are known to contain high concentration of combustible materials in the kitchen, due to the availability of heat sources, as well as highly flammable martials such as cooking oil and grease. Residential facilities would also contain combustibles in fabrics [10]. These materials would usually emit a toxic fumes during fires, and hence cause serious hazards to occupants [26].