Why do fires in commercial structures tend to burn faster?

Fires in commercial structures often burn faster primarily due to the presence of longer truss spans. These structures typically utilize engineered truss systems for their roofs and floors, which can create larger unconfined spaces. This allows for greater airflow and more rapid fire spread, as the flames have more area to engage with combustible materials.

Additionally, the materials used in commercial construction, such as lightweight wood or metal, can contribute to the speed of combustion. The design of these trusses often means that they can fail quickly under fire conditions, leading to rapid structural collapse once they are compromised, which in turn can exacerbate fire spread.

In contrast, other factors such as humidity, response times, and open areas can play a role in fire dynamics but do not inherently increase the burn rate of a fire in the same direct way as the structural configuration provided by longer truss spans.