What is the minimum distance of vertical firewall projection downwards according to BP 220?

The minimum distance for vertical firewall projection downwards according to BP 220 is set at 300 mm. This requirement ensures that the firewall effectively serves its purpose of containing and limiting the spread of fire between adjacent properties or sections in a building. By setting this minimum distance, the regulation aims to enhance safety and compliance in building designs, providing adequate separation that minimizes fire risks.

A distance of 300 mm allows for sufficient coverage and stability of the firewall, which is crucial for preventing the passage of flames or hot gases, thus contributing to the overall fire safety measures in building construction. This regulation reflects a careful consideration of practical engineering needs, ensuring that firewalls can perform effectively in the event of a fire emergency.