Common causes of fire on construction sites

OCT 29,  2019

fire concerns


Construction sites and buildings undergoing refurbishment suffer a number of serious fires every year, and most worryingly the total number of fires occurring on construction sites has been on an upward trajectory for the past four years. There are around 11 construction fires taking place every day. 

The risk of fire on construction sites is particularly severe due to the number of high-risk activities that take place onsite. It is also important to note that the risks on site are not restricted to those working there. 

For instance, if a large fire starts on a construction site, property nearby could be at risk, including the lives of the occupants and members of the public in the surrounding area. For this reason, it is essential that the correct control and precautionary measures are put in place to reduce the risk of onsite fires.

For a fire to start, three things are needed: a source of ignition, a source of fuel and oxygen. On a construction site, there are many potential sources of ignition. HSE lists a few of these as: 

  • Heaters

  • Lighting

  • Naked flames

  • Electrical equipment

  • Hot processes (such as welding or grinding)

  • Smokers’ materials (cigarettes, matches etc)

  • Anything else that can get very hot or cause sparks.  

Read on to discover the most common sources of ignition on construction sites and how to control these risks to ensure you are fire safety compliant. 


construction site safety


Electrical faults 

Every construction site, no matter how big or small, carries the risk of a fire starting onsite. However, the sites that most frequently suffer fires are areas undergoing refurbishment, demolition or reconstruction. 

The reason for this is the amount of old electrical cabling or dry wood present onsite that workers may not have noticed. As mentioned above, the number of high-risk activities that take place onsite significantly increase the risk of fires starting, due to the likelihood of sparks being emitted from construction work like soldering or sawing. When these sparks come into contact with electrical cabling or dry wood, it won’t take long for a fire to start. 

As well as the presence of old electrical cabling, temporary electrical lighting and portable equipment are one of the most common causes of fires on construction sites. Construction sites often require lighting of work areas by temporary lighting systems or from specific task lighting. 

The risk of fire comes from having this lighting placed too near combustible items, not allowing the lamps to cool, or from broken lamp units where hot surfaces are exposed. Along with temporary lighting, construction sites also have a combination of fixed electrical wiring from mains sources and electricity generated from mobile power generators. 

To control this risk, any temporary lighting units should be placed away from combustible material, and halogen and halide lights should not be used because of their high operating temperatures. To reduce the risk of fires due to electrical faults on site it is essential that all electrical installations are tested, inspected and commissioned before becoming available for use. 

Portable Appliance Testing (PAT) should be carried out in accordance with the HSE guidance note HSG107 which advocates a risk-based testing policy. Electrical installations must also meet the BS 7671: 2008 requirements for electrical installations, which includes a specific section on construction sites. 

Other legal requirements when it comes to fire safety would be contained in the CDM Regulations 2015,  which imposes duties you must undertake to prevent the risk from fire. The fire risk from site activities must be assessed and precautions taken to control ignition sources.

To control the ignition source risk from old electrical cabling, temporary lighting and portable equipment you must inspect and monitor these hazards. This involves ensuring temporary lighting, halogen lamps, and display lighting is not too close to combustibles. It also means making sure that any electrical equipment is installed, used, maintained and protected in accordance with the manufacturer’s instructions.    


Flammable solids, liquids and gases

There are many solids, liquids and gases present on construction sites that can catch fire and burn quickly. It only takes a source of ignition from an electric spark or naked flame to start a severe fire. 

Often combustible rubbish is left around the site, posing a fire risk. It is therefore essential that all rubbish is cleared and removed from the site as soon as possible. 

The Site Waste Management Plans Regulations 2008 (SWMP)R are enforced by the Environment Agency. SWMP sets out how building materials and resulting waste are to be managed during the project. When developing the waste management plans, the fire risk should be assessed and any controls deemed necessary implemented. 

To control the risk of fire-induced by combustible rubbish around the site, you should set site rules and make sure these are implemented seriously. For instance, contractors must clear their rubbish from the site at least daily. It is also important that facilities for the storage of rubbish are provided so that when rubbish is on-site it is contained. 

You should also ensure that these containers are positioned in an area where, if they were to catch fire, they do not put the site or nearby properties at risk. 

Other measures you can take to reduce the risk of site fires caused by combustible rubbish include:

  • Keeping flammable rubbish, such as contaminated rags, in a closed-top, fire-resistant container.  

  • Store empty bulk fibre bags, sacks and wooden pallets in a safe area until they can be removed from the site. 


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How to ensure compliance 

In every construction site, there must be a designated ‘Responsible Person’ whose duty it is to ensure that action is taken to both prevent fires and prevent injury or death if a fire occurs. The UK fire safety legislation states that you must provide ‘appropriate fire-fighting equipment’. 

By ‘appropriate’ the legislation means that your fire-fighting equipment i.e fire extinguishers must be maintained in good working order, undergo an annual maintenance test and may need to be certified to industry standards.  

Here at Howler, we make fire safety compliance easy. Our self-service fire extinguishers possess an array of third-party certification, including the Kitemark, verifying its compliance with BS EN3 and the manufacturing standard for fire extinguishers. They are also manufactured so that the user is able to carry out the annual inspection and test, as well as the routine visual checks, reducing the need for out-sourced maintenance.

In addition to our compliant fire extinguishers, we also have a range of wireless alarm systems that are essential for keeping your construction site fire safety compliant. 

Installing a fire alarm system on a construction site poses a challenge as the site changes on a daily basis; the continual adding of new floors and walls makes it highly difficult to use a wired system because of the need to constantly reposition wires and call points.

Our GoLink wireless is simple to install, use and maintain and is perfect for ensuring fire safety on a construction site. This system was used at Royal Arsenal Riverside, part of the South East London regeneration program. 

For this project, our clients had an increased responsibility to install an effective fire warning system in place, due to the large numbers of people living and working in close proximity to the construction sites. 

Our GoLink wireless provided the perfect solution, ensuring full coverage of all areas of the site. By choosing a wireless system moving the units as the project progresses has been simple and quick, keeping maintenance time to a minimum.  

More advice on construction site fire safety… 

For more advice on construction site fire safety compliance get in touch with our knowledgeable team on +44 (0)330 7000 777 or With 30 years of experience, we can help you keep up with all of the rules and regulations and ensure that you achieve compliance as quickly and effectively as possible. 


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