What is the quickest way to check for vertical fire spread in balloon-frame buildings?

The quickest way to check for vertical fire spread in balloon-frame buildings is through the method of opening the siding panels from the outside of the fire area. Balloon-frame construction has a cavity that extends from the foundation to the roof, allowing fire to travel vertically through these hidden spaces. By accessing the exterior siding, firefighters can visually or physically inspect these cavities to determine if the fire has spread upwards without having to breach the interior walls first, which could take more time and is often more complicated.

This method provides a more immediate visual assessment of whether flames or heat are present in these vertical channels. Since fire can spread rapidly in balloon-frame constructions, this direct approach is critical for quick identification and effective firefighting measures, allowing crews to address any threats before they escalate.