Fire Barriers

In the context of building construction, cavities are an integral yet often overlooked aspect. These are essentially the empty spaces or gaps found within the structure of a building, particularly in walls and floors. Typically, in walls, cavities exist between the outer brick or block layer and the inner layer, which could be made of blocks, bricks, or a framed construction. In floors, these spaces might be between the different layers that make up the floor structure.

The primary purpose of these cavities in building design is multifaceted. They serve as a barrier against moisture penetration, helping to keep the interior dry. In walls, these cavities can also contribute to thermal insulation, aiding in energy efficiency by creating a buffer zone that reduces heat transfer. They can also be used to conceal electrical wiring, plumbing, and other services, keeping them out of sight while still accessible for maintenance.

While cavities offer these benefits, they also present significant risks in fire scenarios. In the event of a fire, these empty spaces can act like channels or chimneys, allowing flames and hot gases to spread rapidly throughout the building. This can occur vertically, allowing fire to move quickly between floors, or horizontally, spreading the fire across a wider area of the same floor. This rapid spread not only poses a direct threat to the structural integrity of the building but also significantly reduces the time available for occupants to evacuate safely.

Understanding the role and risks associated with cavities in buildings is crucial for effective fire safety planning. It highlights the importance of implementing measures such as fire cavity barriers, which are designed to seal these spaces and prevent the spread of fire and smoke, thereby mitigating one of the key risks in building fire safety.