How much higher must single-wall metal pipe extend above the roof where it passes through?

The requirement for single-wall metal pipe to extend above the roof is set to ensure proper ventilation and to prevent the buildup of harmful gases. Extending the pipe by two feet above the roof line allows for adequate dispersion of combustion gases, reducing the risk of backdrafts and ensuring that any exhaust is directed safely away from the building and outdoor spaces.

In addition, this height helps to mitigate potential fire hazards by keeping the exhaust gases at a safe distance from nearby structures, vents, or other surfaces that could be ignited. Building codes and safety regulations are designed to protect both the integrity of the structure and the health of its occupants, and this specific height requirement is a standard practiced in the industry for ensuring safe operation of appliances that utilize propane.

Other height requirements, such as one foot, three feet, or four feet, do not adhere to the recommended guidelines that provide an effective dispersion of exhaust and ensure safety for nearby flammable materials.