A fire compartment (Dutch: brandcompartiment) is a defined section of a building enclosed by fire-resistant walls, floors, and doors that is designed to contain a fire and prevent it from spreading to adjacent areas. By dividing a building into compartments, occupants gain time to evacuate and firefighters can localise the blaze.
How fire compartments work
The principle is straightforward: if a fire starts in one compartment, the fire-resistant boundaries keep flames, smoke, and heat from reaching neighbouring compartments for a specified period — typically 30, 60, or 120 minutes depending on the building type and local regulations.
Every opening in a compartment boundary — doors, windows, ducts, cable penetrations, and pipe passages — must be sealed or fitted with fire-rated closures. A single unsealed cable hole can compromise an entire compartment, so attention to detail is critical.
Fire resistance ratings
Compartment boundaries are rated by their ability to maintain three functions during a fire:
- R (Résistance) — load-bearing capacity. The element continues to support its structural load.
- E (Étanchéité) — integrity. The element prevents flames and hot gases from passing through.
- I (Isolation) — insulation. The element limits temperature rise on the unexposed side.
A wall rated REI 60, for example, maintains all three functions for at least 60 minutes.
Application in construction
Building regulations prescribe the maximum size of a fire compartment based on the building’s use and occupancy. Residential buildings, hospitals, schools, and high-rise structures each have different requirements. During design, the architect and fire safety engineer map out compartment boundaries and specify the required fire resistance for each element. During construction, ensuring continuity of the fire-resistant envelope — especially at joints, penetrations, and junctions — is one of the most important quality checks.
Related terms
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