New research has shown that traveling fires pose a risk to the structures of large open building spaces over 100m2.

The lesser-known ‘travelling fires’, which travel within large building compartments rather than engulfing whole rooms at once, can cause at least as much structural damage and potential building collapse as typical fires. They are likely to be especially prevalent in large spaces with ample fuel and fewer doors and interior walls, like open-plan offices and warehouses.

Structural engineers design buildings to survive fires use guidelines like standard fire and Eurocode parametric fires. Using these guidelines, they typically focus on the fires that engulf whole rooms at once, known as flashover fires.

This new research, published today in the journal Fire Technology, shows that open spaces are also vulnerable to travelling fires — a lesser-known fire type that burns locally and moves across an entire floor over time.

Senior author of the paper Professor Guillermo Rein of Imperial’s Department of Mechanical Engineering said: «Previous fire experiments have found that designing against flashover fires is key for buildings with smaller spaces separated by walls and doors. However, now that structural engineers are designing large open-plan spaces more frequently, it’s important to better understand how fires behave in these spaces.

«We found that buildings with open plans are in fact vulnerable to travelling fires, but this fire type is not yet weighted as heavily as flashover fires when designing buildings. We want engineers to understand that protecting against travelling fires could be just as important as protecting against more typical ones. By considering both fire types, engineers can be confident that they are considering the worst-case scenario.»

Travelling fires

Story Source: Materials provided by Imperial College London. Original written by Caroline Brogan. Note: Content may be edited for style and length.