Benefits of modular construction
Lower labour costs, less materials, shorter construction time and higher quality. These are just some of the benefits of modular and prefabricated construction. Rather than laying brick by brick and pouring concrete on-site, several components are built in a factory and transported on-site. With a cost focused housing market, there is a need for exactly these kinds of solutions to meet the demand.
What to be aware of?
The likelihood of fire hazards in modular constructions has received new attention after the Moorfield Hotel fire in the summer of 2020. In this article, we will take a deep dive into the risk of fire hazards in especially modular and prefabricated buildings. Lastly, we will outline what precautions there should be considered in order to minimise the risk of fire hazards.
Fire hazards in modular constructions: An example from summer 2020
The Moorfield Hotel in the Shetland Islands burned to the ground after a devastating fire (source: BBC). The 106-bed hotel was manufactured offsite using insulated panels and modules utilising sandwich-construction. The construction consisted of a wooden board (OSB), using a polyurethane foam insulation, and close to the void or gap between the modules, there was another OSB board (source: FPA).
This void in the construction was about 12 millimetres wide, which meant that there was wooden material on both sides of this void. Both the wooden board (OSB) and the Polyurethane foam are highly combustible materials, which may have been contributing factors to the severity of the fire.
Insights for your next construction project
According to Andreas Kräling and Sören Isaksson at If, this type of construction is unfortunately common in modern construction, and several large losses have occurred as a result of combining modular constructions with combustible building materials.
There are precautions that builders and developers should take into consideration to minimise the risk of fire hazards and still benefit from cost-effective construction methods. Andreas Kräling and Sören Isaksson have provided insights into some key considerations for your next construction project:
1. Engage If’s risk engineers as early as possible in the planning stage
Engaging If’s risk engineers in the early planning stages of e.g. the construction of a large industrial building, will result in a thorough understanding of the existing as well as potential risks. In the early planning stage, If’s risk engineers can provide advice, based on lessons from losses, e.g. the use of non-combustible building materials to ensure that adequate fire protection is installed.
According to Sören Isaksson, Senior Risk Engineer, Risk Management Services, “It’s important for me to emphasize that voids inside a construction made from combustible materials is a huge potential risk. If a fire finds its way to this void, it is extremely difficult to access by the fire brigade or a sprinkler system installed in the rooms. An uncontrolled fire spreading in the voids can as in the Moorfield fire lead to a complete loss of the entire building”.
2. Install a reliable fire safety system concept
A well-designed and properly installed sprinkler system will prevent the fire spreading, control or extinguish it. However, despite the importance of a well-functioning sprinkler system, it should never be at the expense of additional fire safety systems, such as fire detection systems, reliable firewalls and other passive fire protection. The sprinkler system should be connected to the fire alarm system relaying the alarm to the rescue services.
The active and passive fire protection installations should be commissioned and approved by a third party. To ensure effectiveness of the active protection systems, assembly and quality of works are essential, as unintentional voids and gaps risks compromising the fire safety concept.