What are the two major challenges firefighters face when dealing with fires in stacked material?

When dealing with fires in stacked material, firefighters primarily face challenges related to water application and collapse hazards.

Water application can be complicated due to the way materials are stacked, which can create voids and pockets within the piles. This makes it difficult for water to penetrate deeply enough to effectively extinguish the fire. Furthermore, the arrangement of the stacked materials might obstruct direct access to the fire, requiring careful consideration of how to apply water without risking further spreading the flames or creating additional hazards.

Collapse hazards are a significant concern as well. Stacked materials can shift under the heat of the fire or due to the application of water, potentially leading to a sudden collapse of the stack. This presents a risk not only to the firefighters who are on scene but also to neighboring structures and individuals nearby. The structural instability of piled materials means that firefighting crews must be particularly aware of their environment and take precautions to ensure their safety while engaging with the fire.

Other challenges, like smoke inhalation, heat exhaustion, visibility issues, and personnel safety, are always concerns in firefighting but are not as specific to the unique circumstances posed by stacked materials as water application and collapse hazards are.