RETROFITTING EXISTING BUILDINGS IN GHANA FOR FIRE SAFETY
Years after construction of many Ghanaian buildings, significant retrofit activity is required to maintain these buildings to current safety and efficiency standards.
Thousands of fires occur each year, resulting in millions of cedis of damages and thousands of fatalities and injuries. The major causes of fire in existing buildings in Ghana includes cooking with naked fire in the markets, overloading of electrical appliances, improper and old electrical wiring system, illegal tapping of electrical power from the national grid, use of substandard electrical materials, and use of defective generators. The extent of severity in cases of fire is due to congested situations in Ghanaian markets (see Figure 1 - 2), residential buildings, and improper layouts, which makes accessibility by fire tenders always difficult when there is a fire outbreak because every major market in Ghana faces the problem of congestion. For this reason, fire hydrants have been obscured by stalls, and lanes that fire trucks need to use to access the markets are converted into stalls, etc. All of these factors come together to cause the kind of destruction that occurs during such outbreaks of fire. The typical result of these outbreaks is the destruction of goods and structures whose costs run into thousands of Ghanaian Cedis. These losses always become a burden for the occupants because they do not have fire insurance to compensate for their losses.
The key design options to ensure fire safety are (Design Buildings Ltd, 2018):
Prevention: Controlling ignition and fuel sources so that fires do not start.
Communications: If ignition occurs, ensuring occupants are informed and any active fire systems are triggered.
Escape: Ensuring that occupants and surrounding areas are able to move to places of safety.
Containment: Fire should be contained to the smallest possible area, limiting the amount of property likely to be damaged and the threat to life safety.
Extinguishment: Ensuring that fire can be extinguished quickly and with minimum consequential damage.
This article seeks to address concerns about upgrading existing buildings for fire safety, maintaining safety and building integrity, whiles preserving the features of that property.
Figure 1: Extracts from a fire outbreak at Dome market in Ghana
Figure 2: Fire destroys portions of old parliament house of Ghana1.1 Objectives
The main objective is to reduce to within standard limits the possibility for death or injury to the occupants of these buildings and others who may become involved, such as fire and rescue team, as well as to protect contents and ensure that the building can continue to function after a fire and that it can be repaired.
To provide for the protection of life
To protect the property
To ensure the installation of fire safety devices has minimal impact on the property
2. THE PROCEDURE FOR FIRE SAFETY RETROFITTING
The procedure for attaining a successful fire safety retrofitting in existing buildings in Ghana consists of
an assessment of the buildings
a fire safety assessment
2. an evaluation of objectives
3. selection of proposed solutions: fire safety hardware
4. a review of proposed solutions with authorities
The Fire safety assessment should be performed to determine how the building presently performs in the event of a fire, to define what deficiencies need to be corrected to ensure safe building evacuation and building preservation, and to determine how best to correct these deficiencies in a manner that both ensures fire safety and preservation of the building features. This involves conducting a detailed inspection and independent evaluation of the entire property, including doors, corridors, stairs, construction materials, fire sources, existing fire safety equipment, operational support systems, and the occupancy as part of the total system relative to overall fire safety.
Once the fire safety assessment have been completed, each should be analyzed in the context of the other. The most significant features and the most important fire safety objectives are identified and prioritized. Each priority is analyzed and design solutions explored to meet the objectives of both fire safety and preserving the features of the building.
In the selection stage, the methods of protecting the building occupants and the building are decided. Finalize the fire safety system selection, which began during the evaluation stage.
Once the solutions from the selection phase have been documented, the project team should examine the implications with the authorities having jurisdiction over the various fire safety requirements respective to historic properties. Once jurisdictional review requirements have been satisfied, the project manager may then complete the documentation and issue the drawings for implementation. The building owner must submit plans, obtain necessary permits, and have all the work approved.
The individuals that can be involved in fire safety retrofitting in existing buildings of Ghana is as shown in Figure 3 below.
Figure 3: The retrofitting project team
3. FIRE SAFETY TECHNIQUES
Retrofit will not provide a building with current standard of fire protection, but a level of life safety that will be “reasonable”. To retrofit/upgrade existing buildings in Ghana for fire safety the following technologies are suggested
Automatic fire sprinklers
Chemical and coating methods
Fire alarm and detection systems
Fire resistant walls
Automatic fire suppression systems control and extinguish fires without human intervention. Examples of automatic fire suppression systems include fire sprinkler system (see Figure 4), gaseous fire suppression, and condensed aerosol fire suppression. When fires are extinguished in the early stages, loss of life is minimal since 93% of all fire-related deaths occur once the fire has progressed beyond the early stages.
3.1.1 Automatic fire sprinklers
A fire sprinkler system as shown in Figure 4 is an active fire protection method, consisting of a water supply system, providing adequate pressure and flow rate to a water distribution piping system, onto which fire sprinklers are connected.
Automatic fire sprinklers can be installed in existing buildings (ie. Commercial, residential, markets, household, schools, industrial facilities, warehouses, etc) to suppress automatically small fires on, or soon after an ignition or to contain fires until the arrival of the fire service. Life safety sprinkler system should be installed in accordance with the appropriate standards
Structural damage is normally of secondary importance. By suppressing fire and smoke, sprinklers are an extremely effective means of enhancing life safety and reducing financial losses.The main cause of fatalities in fire is smoke and most deaths occur long before there is any significant risk of structural collapse. Structural damage is normally of secondary importance. By suppressing fire and smoke, sprinklers are an extremely effective means of enhancing life safety and reducing financial losses.
The types of sprinkler systems available are
Wet and dry pipe fire sprinkler system
Pre-action fire sprinkler system
Deluge fire sprinkler system
Victaulic vortex fire suppression system
Figure 4: Automatic fire sprinkler
A properly selected sprinkler will detect the fire's heat, initiate alarm, and begin suppression within moments after flames appear. In most instances, sprinklers will control fire advancement within a few minutes of their activation, which will in turn result in significantly less damage than otherwise would happen without sprinklers.3.2 Chemical and Coating Methodsa. Fireproof paint
Fireproof paints are frequently used in public buildings and facilities, residential, commercial and industrial buildings and structures, office buildings, entrance halls, parking garages, governmental buildings, markets, new or old buildings, etc. This product could be applied directly onto surfaces with alternative colours, which makes it a good option for protecting historical and old buildings against thermal effects. Even the interior or exterior of timber structures can be painted with the appropriate intumescent paint.
The use of this product can prevent spread of fire and help decrease high smoke levels. The experimental tests on this product indicate that when exposed to flame and fire, the fireproof paint swells because of thermal reaction and produces an insulating barrier that protects members.
In case of fire, a fireproof paint guarantees extended evacuation time, as well as vital extra time for firefighters to arrive and minimize damage.
Fireproof paint, in general, comes with the following advantages:
Can provide fire protection up to 120 minutes
fire resistant paint can be applied before or after construction
Fireproof paints are applicable on wood, steel, concrete, textile and plastics.
lasts for decades and makes the surface impact resistant
if applied as a top coat, fireproof paint is available in every RAL color
Spray Fire Resistive Materials (SFRM) prevent the spread of fire and help reduce the smoke levels. These coatings provide protection to structural steel in buildings and other structures by serving as an insulative layer in the event of a fire. The coatings are rated by how long they provide such protection, typically from 1/2 hour to 4 hours.
c. Concrete Coating
Concrete coating is the covering, typically liquid or semi-liquid, that is applied to cured concrete for aesthetic reasons as well as to make the structure or surface last longer and to reduce maintenance and repair costs.
Concrete has some degree of inherent resistance to the effects of fire, retaining its structure even when exposed to a fire fueled by cellulosic material such as wood or paper. However, in older buildings where the fire protection needs to be enhanced, architects would traditionally increase the thickness of the concrete, install mineral fiber-board or turn to spray-applied mineral fiber products. Contractors can protect concrete by using a water-based intumescent coating.3.3 Fire alarm and detection systemsThe first step toward halting a fire is to properly identify the incident, raise the occupant alarm, and then notify emergency response professionals. This is often the function of the fire detection and alarm system. Several system types and options are available, depending on the specific characteristics of the protected space.Alarms, fire and gas detection systems should be installed within all areas of the building. Fire extinguishers have to be positioned at vantage points within the building (See Figure 5).
A fire-stop is a fire protection system made of various components used to seal openings and joints in fire resistant rated walls and/or floor assemblies. Fire-stop is required for all new construction, retrofit projects, industrial, institutional, and commercial buildings (eg. Apartment buildings, hospitals, schools, nursing homes, office buildings, stairwells, markets, etc). Examples of fire-stop products include mineral wool, intumescent sealant, silicone, silicone SL, acrylic sealant, spray, mortar, foam, collars, wrap strip, putty pads, inserts, putty, fire-stop pillow/blocks, sleeves, composite sheet, etc
3.5 Fire Partitioning
A partition is defined in British Standards as an "internal, dividing, non-load bearing, vertical construction". In European (CEN) standards, it is defined as a non-load bearing wall, and EOTA European Technical Approval Guideline for partitions, is entitled "Internal partition kits for use as non-load bearing walls". A partition may be used for space division within the building, to separate areas of different floors, or used as an independent lining to an external wall.
Fire-rated partitions are internal walls that provide vertical fire separation in structures such as dividing walls. As shown in Figure 6, examples of fire partitions are firewalls, fire-rated doors, fire resisting ducts or dampers, fire rated ceilings, etc. Once a fire has become fully developed, it attacks the structure of the compartment and tries to spread beyond the compartment of origin. A fire-rated (fire-resisting) partition prevents this by creating a structure (i.e., a compartment) which does not collapse and contains the fire for a given period of time.
Use a fire-rated partition or fire resisting partition for which the fire resistance performance has been determined according to the appropriate British or European standards. The fire resistance of such partitions ranges from 30 to 240 minutes (or more).
Figure 6: A fire rated partition (CIS, 2018)
Fire rated ceilings with enhanced fire protection properties may need to be considered when designing or renovating. A fire-rated ceiling will have been tested by the manufacturer to retain structural integrity for a set period (usually 30 or 60 minutes), and indicates how effectively the ceiling can hold back fire and prevent it from spreading from room to room.
3.5.1 Constructing new fire-rated doors
Doors serve as a crossing point between exit access corridors and exits as well as a crossing point between exits and exit discharges. In both cases, the doors should be fire rated and kept in the normally closed position in order to maintain the fire-rated integrity of the exit and to prohibit products of combustion from interfering with occupant way out. Another method for providing a fire-rated equivalency for a door could be by protecting each side of the door with automatic fire sprinklers. This method could be used in lieu of replacing the door, or if other means of complying with the fire and building codes would permanently alter the old door. Construct new fire-rated doors as a component of the means of egress in a manner that creates the required fire- rated assemblies.
3.6 Electrical Safety
Electrical fires is mostly caused by wiring that is exposed or not up to standard, overloaded outlets, extension cords, overloaded circuits, static discharge, and so on.
The electrical installations in many existing buildings were constructed decades ago in accordance with the state-of-the-art technology at that time and have not been modified since. In Ghana, most residential buildings are more than thirty (30) years old, and eight (8) million of these are more than forty (40) years old. Yet, the average service life of electrical systems is only Thirty (30) to thirty-five (35) years. When buildings are overhauled, the electrical installations are often neglected. A similar picture exists in commercial and industrial buildings.
The number of electrical loads has drastically increased over the past decades: Whereas there used to be roughly eight electrical devices, today there are often more than fifty (50) electrical loads in a given household. Kettles, dryers or microwave ovens were previously rare commodities up into the 1980s; entertainment electronics in their current form, computers, heat pumps and power generators such as photovoltaic systems did not exist. The outdated electrical installations in many buildings can hardly cope with these loads anymore. Another point to consider is that modern electrical devices often have different power consumption characteristics or have frequency converters. In the event of a fault, these can create residual currents with higher frequencies or smooth DC residual currents, requiring special protective devices, which many people do not know.
What's more, the old-fashioned electrical systems designed for the range of appliances in the 1960s and 1970s can hardly be connected to the Smart Grid or regularly supply electricity over a longer period. That is why the modernization of electrical installations is not only the precondition for electrical safety but also the basis for sustainable energy concepts.
Arcing faults in electric cables or systems are among the most frequent causes of fires. Arc Fault Detection Devices (AFDDs) is strongly recommended in existing buildings (eg. Homes, markets, commercial and residential buildings, etc) to close this previous safety gap. The devices are capable of detecting all types of arcing faults. Install AFDDs on the electrical circuits most exposed to risk – e.g. the final circuits that supply socket outlets. The AFDDs is easily installable in new buildings, but as the first product for preventive fire protection, it also features straightforward retrofitting in existing buildings. The new standard IEC 60364-4-42 strongly recommends the installation of AFDDs in specific locations of use as the recognized state-of-the-art technology (Siemens, 2018).
The key to preventing electrical fires in industrial buildings is awareness and prevention (Nilfisk, 2018). The following electrical safety practices can be adhered to
Do not overload electrical equipment or circuits.
Do not leave temporary equipment plugged in when it is not in use.
Avoid using extension cords, and never consider them permanent solutions.
Use anti-static equipment where required.
Follow a regular housekeeping plan to remove combustible dust and other hazardous materials from areas that contain equipment and machinery.
Implement a reporting system so that anyone who observes an electrical fire risk can report it without consequences.
Only certified electricians must be permitted to wire buildings, the government should implement electrical safety education on our televisions stations as well as various radio stations. Every building should have a fire extinguisher approved for an electrical fire.
The cost of retrofitting existing buildings, health and safety requirements during retrofitting, poor maintenance culture of building owners, building tenants’ resistance to retrofitting works, inadequate government legislation among others are identified as some challenges to retrofitting and adapting existing buildings for fire safety. I therefore suggest that policy makers and practitioners should put in place measures for curbing such occurrences.
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Coatingpaint (2018). How to Use Fireproof Paint to Protect Your Building. [Online] Available at: https://www.coatingpaint.com/fireproof-paints/[Accessed 1 August 2018].
Design Buildings Ltd (2018). Design Buildings Wiki. [Online] Available at: https://www.designingbuildings.co.uk/wiki/Fire_safety_design[Accessed 3 August 2018].
Nilfisk (2018). Industrial Vacuum Cleaners. [Online] Available at: https://news.nilfiskcfm.com/2016/07/5-major-causes-of-industrial-fires-explosions/[Accessed 10 August 2018].
Siemens (2018). Preventive fire protection in electrical installations, Germany: Siemens.