What is the minimum height requirement for a parapet firewall above the roof surface where it intersects with the wall?

The minimum height requirement for a parapet firewall above the roof surface where it intersects with the wall is specified to ensure that the firewall effectively serves its purpose in preventing the spread of fire. A height of 1/2 inch is sufficient to maintain structural integrity and provide the necessary barrier without being overly intrusive or difficult to implement on various building designs.

This specific height helps in meeting safety codes that aim to protect buildings from fire hazards while accommodating practical construction considerations. It ensures that the firewall is somewhat elevated to direct water run-off and prevent pooling, which is especially important in protecting both the firewall and the building structure during inclement weather.

Higher requirements, such as the options of 3 inches, 2 inches, or 6 inches, may be considered more than necessary within the context of typical construction practices, making the 1/2 inch standard effective and compliant without being excessive.