The Official E-Newsletter of the Institution of Engineers Sri Lanka   |  Issue 47 - April / May 2020


Necessity for Awareness, Prevention and Preparedness for Fires in Construction Sites

By : Eng. T L R Thilak Silva

Classic Examples of Recent Fires at Construction Sites

I was prompted to write this article after seeing the news that a 42 storied hotel building which is now under construction at the Bambalapitiya junction, had caught fire on 28th Feb 2020. News mentioned that five fire engines of the Colombo Fire Brigade had been brought to douse the fire. It was in the news everywhere and negative publicity which this incident had given was quite damaging to the reputation of the client and the contractor. Reason was not known how the fire had started but it had happened in the basement floor where the furniture brought for the project had been stored. Fortunately the fire had been extinguished fast and the damage has not been so extensive, but the damage to the reputation was immense. One of the leading international hotel chains has signed agreement to manage this hotel once it is completed. What should be their reaction to such negative incidents and impact to their global reputation? The main structure had been completed by an International Chinese Contractor but the finishing work has been subcontracted to individual companies which are managed directly by the client.

My first scary experience of a fire at a construction site was when I was involved in a Greenfield project to build a Glass Factory in Horana in 2007. The construction work was in the finishing stages and the factory equipment suppliers were in the process of commissioning the furnace. All the pipe lines supplying LPG gas to the furnace were active and the client by that time had not thought about the permanent fire detection and protection system for the building. We only had our portable fire extinguishers kept at key locations of construction works. On that day, when I was in the site office, I heard a loud bang around 6.00 pm in the evening like that of an explosion from inside the factory building. Soon we realized that it was a fire inside the factory building close to the furnace. One of our workers was using an oxy-acetylene cutter for some civil works inside the building close to the Furnace area. It had back fired and the flames had traveled back to the cylinders throwing out the acetylene cylinder up in the air causing a loud bang noise and fire erupted due to the continuous floor of oxygen from the Oxygen cylinder. Fortunately an Indian National who worked with the Consultants acted promptly together with our Project Manager who was in the close proximity, to douse the fire. If such quick action had not been taken, the oxygen cylinder could have blasted creating a major fire and might have caused damage to the LPG gas pipe lines, setting the whole factory building and its valuable machinery ablaze in moments. The total investment of the project could have been ruined. Reason for the back fire of flame to the cylinders was that the safety non-return values were not fitted to the equipment.

My second experience of a fire at my own site was when I was working for a construction company in a hospital project to construct a 10 storied building for National Hospital Colombo in 2015. Construction was at the final finishing stages. Two of subcontractor’s workers were installing vinyl carpet inside a ward room in the 7th floor. They first apply the adhesive on the floor screed and then lay the vinyl sheets. Suddenly a wire short and a spark occurred in the temporary wire connection supplying electricity to the lights and the highly inflammable adhesive caught fire. Then a fire erupted inside the room and the carpet started burning. Fortunately two of our own workers, brave and loyal to the team, jumped into the room through a window in the rear passage with the fire extinguishers and doused the fire instantly. Spreading of fire beyond the confined spaces of this room was prevented due to the bravery of these two workers. If a major fire had erupted in this building and if the fire brigade had to be called, it should have given immense negative publicity to the company. It could have caused a major panic among the patients in the adjoining functional buildings of the National Hospital. Cause of the fire was due to the negligent wiring of the temporary electrical supply.

Major fire occurred in a construction site at Hyde Park Corner last year, was another recent incident. The contractor was a reputed construction company. This building site was located next to a 22 storied newly built office building. This fire erupted within the worker accommodation which was housed within the ongoing construction site. It happened during midday when the workers were cooking their lunch. The cause was a defective hot plate. It is common practice in the major building construction sites to shift their worker accommodation to the completed floors of the building structure. The sleeping facilities for the workers are made with timber frame work and plywood sheets which are combustible materials. The sleeping mats and pillows are also highly combustible. Even if a slightest fire occurs within such an environment, fires can spread uncontrollably. The fire had spread to the adjoining building which was the office of an international audit and management consultancy company. Their important records and the computers were gutted in fire causing a serious damage to their premises. Until the fire brigade came to the scene, the maintenance crew of the adjoining high rise building had started dousing the fire and prevented it spreading to their building using their permanent fire extinguishing system. One may ask the question whether the contractor had taken due care and diligence to prevent this fire.

There was another classic example of a fire in a hotel construction site in Galle in which a fire broke out in the roof top in 2018. The day was a Poya day and it was in the evening. There were some combustible materials which were brought for an architectural feature and were stored on the roof top close to where it was to be installed. Reliable source said that the fire had initiated due to the heat emanated from a 1000 W bulb which had been placed unintentionally closed to this inflammable materials. Security had switched on the lights in the evening, and this material had caught fire without any one’s notice. Workers were not on this floor as the site had closed early due to that day being a Poya holiday. Fortunately a group of people from a nearby place had seen the fire and had immediately notified the fire brigade. The Fire Brigade had come and doused the fire before it caused extensive damage to the building. The whole building might have caught up in fire if not for the timely action by this unknown group of people.

Similar fire broke out at the pool level of a high rise apartment building in the Union Place in 2014, while the building was under construction. Water proofing plastic membranes which were combustible, were stored on the pool deck slab at 6th floor. Directly above where these materials were stored on 6th floor, there were some hot works which were being carried out using gas cutters to remove the scaffolding supporting steel brackets at the 27th floor. They say that a heated piece of steel from this gas cutting process had fallen on to the plastic waterproofing materials on the 6th floor and this highly combustible materials had ignited a fire. The plastic sheets were caught up in fire and later the fire had spread to the outer safety nets. Fire had travelled through the safety nets to the floors immediately below and above on the 5th and 7th floors. The Apartments in the 5th and 7th floors were badly damaged due to the fire. Fire was later brought under control by the Colombo Fire Brigade but the damages were extensive.

Domestic House Fires

In order to impress upon the readers the agonizing consequences of fires in buildings, I wish to write about a domestic house fire which occurred last year in a neighboring house of a close friend. It was in a two storied house which was located at Wattala. The owner of the house was a journalist and a writer. He had lot of books stored in the house. During this time of his life he had various problems which people face during the course of their lives, but this person and his wife thought these problems are due to some supernatural influences. Then they decided to consult a spiritual person who used divine powers of a deity to solve their problems. The spiritual person advised the house owner to light twelve oil lamps in front of the statue of the deity every evening for certain number of days. So, he lit the lamps on this dooms day in his study room where the statue of the deity was placed and after the prayers, the whole family went to sleep. During the midnight some rodents had invaded the place where the oil lamps were placed and made one oil lamp to fall on the ground. The oil had spilt from the lamp on the floor slab and caused a fire which had spread to the book shelves. The house was on fire. Fortunately the wife had awoken feeling some unusual sensation and having realized what was happening, had managed to get the husband and the children out of the house with moderate burn injuries. In few minutes the total house was burnt and two pet dogs inside the house had burnt to death. Fortunately the fire had not invaded the adjoining neighboring houses due to the arrival of the fire trucks which doused the fire. All his books and lot of valuable literature were burnt and perished in 30 minutes. It is like that the place of worship had fallen on the worshipper. The family lost all their wealth and the place of dwelling in few moments.

From all these real stories there is one clear message that the reader needs to get deep inside his/her head that identifying fire hazards on daily basis is essential whether it is in a building construction site or it is a domestic house.

Fire Occurring Instances are Very High in Construction Sites

In construction sites, probable chances of occurring a fire is high. Consider a situation when the erection of conventional formwork for a floor slab is in progress. The formwork comprises of timber joists and plywood sheets which are combustible materials. We do certain hot works such as welding of earthing rods, water bars, and side board tie bars etc or use gas cutters to cut rebar on such formwork. There is a very high probability for the plywood sheets to catch fire due to the sparks from the hot works, reason being that even the form oil (or mix of diesel and grease which we use as form oil) is highly inflammable. If a slab formwork catches fire, it can give rise to a major fire. Then the fire can spread to the safety nets and there is a possibility of spreading the fire to the other floors and neighboring buildings.

I have seen at sites, where containers filled with petrol and other inflammable fuels are placed and locked inside open mesh cages outside the site main stores, which are visible to the site workers. What will be the situation if a disgruntled worker who is provided accommodation within the site premises, in the middle of the night, come down to the place where the fuel containers are stored and light a match and throw it to the open cage containing highly inflammable fuel containers. Fuel containers will catch fire and the fuel will spread all over the place instantly spreading the fire to the main stores and other storage areas containing combustible materials. Such things can probably happen.

Awareness, Prevention and Preparedness

Hence it has enough been emphasized that the project managers and the senior management should drive the awareness, preventive action planning and preparedness in case of a fire, in every building project site. Following actions are proposed.

  1. Form a fire action committee with staff nominated from functions across the project.
  2. Dedicate few minutes in daily staff meetings to identify fires risks in each day’s work.
  3. Identify inflammable and combustible materials at all stages of project life cycle and give due consideration how such materials should be stored away from any fire triggers.
  4. Strictly impose system of Hot Work Permits before any fire related works are carried out at any level. Hot Work Permits will analyze all probabilities a fire can instigate during such work and will brief what preventive actions are planned. It will also go through several approval levels.
  5. Wherever possible, avoid worker accommodation within the completed areas of the building structure. If it is unavoidable and costly to have accommodation away from the building structure, impose strict rules and strict controls to avoid worker’s negligence which can trigger fires in the worker accommodations.
  6. Always be attentive to prevent worker sabotage that can instigate fires.
  7. Provide protective areas for storage of fuel containers where workers cannot access and are visible to them. Example of two cage system where inner cage is a close cabinet and outer cage is an open mesh lockable area may give necessary protection.
  8. Have regular fire drills at site with the assistance of professionals from the fire brigade or any other expert agencies.
  9. Set up fire emergency action plan and assign people who will be responsible to act in case of a fire. It will also detail how each person should react in case of a fire at its initial stages to douse the fire without spreading it to other areas. And at what stage and who will call the Fire Brigade etc.

Similarly we need to have necessary safety precautions and awareness in place in our domestic dwelling places.

  1. Gas cylinders should be stored in ventilated areas.
  2. Any inflammable liquids should not be kept close to the stoves and fire places.
  3. Open oil lamps kept in worship areas should be safely placed to avoid falling from such locations due to any rodent movements that can instigate fires.
  4. Old houses should be checked for electrical wiring.
  5. Areas of storage of combustible materials such as book shelves should be kept away from any possible fire hazards and triggers.
  6. Due care should be taken in the areas where cloth ironing is done. Ensure any electrical equipment and accessories which are subject to fire risks are switched off before the occupants leave the house and before going to sleep.

Conclusion

Fires are agonizing and painful. Companies and families can lose everything in one single day. It will affect the careers of people who are involved in the management of such projects. We can lose our co-workers and colleagues during such fires. We can lose our loved ones in domestic fires.
So we all have a responsibility to take all necessary precautions to prevent fires in our construction sites and in our homes.

T L R Thilak Silva BSc Eng (Hons), MEng, MIE(SL), MICE



Eng. T L R Thilak Silva
BSc Eng (Hons), MEng, MIE(SL), MICE

 

 

 

 

Presently working at Maga Engineering (Pvt) Ltd., as a Deputy General Manager (Construction). Passed out from University of Moratuwa in 1986. Worked initially with the Consultancy Companies as a Structural Engineer. Worked overseas in Oman, Tanzania, Kenya & Uganda.