How many feet should a true firewall extend over the roof?

A true firewall is designed to provide a barrier against fire extending from one structure to another, which is crucial for preventing the spread of fire in multi-structure environments. The requirement for a firewall to extend a minimum of 3 feet over the roof is important for several reasons.

Firstly, this extension ensures that there is a physical barrier preventing flames and heat from breaching the wall at the roofline, where the structure may be more vulnerable. A firewall that extends adequately beyond the roof helps to protect adjacent structures and ensures that embers or direct flames do not easily jump over the firewall during a fire event.

Additionally, building codes and safety regulations typically dictate these distances to establish a uniform standard across various buildings, making it imperative for safe construction practices. Getting this measurement correct reinforces both the fire safety management and the overall integrity of the building structure in the event of a fire.

Thus, the requirement for a firewall to extend 3 feet over the roof provides a critical defense against the vertical spread of fire and helps maintain safe distances between adjacent buildings.