// CODE SNIPPET
509.6.1 Termination Requirements
JUMP TO FULL CODE CHAPTER
A gas vents shall terminate in accordance with one of the following:
- Gas vents that are 12 inches (300 mm) or less in size and located not less than 8 feet (2438 mm) from a vertical wall or similar obstruction shall terminate above the roof in accordance with Figure 509.6.1 and Table 509.6.1.
- Gas vents that are over 12 inches (300 mm) in size or are located less than 8 feet (2438 mm) from a vertical wall or similar obstruction shall terminate not less than 2 feet (610 mm) above the highest point where they pass through the roof and not less than 2 feet (610 mm) above any portion of a building within 10 feet (3048 mm) horizontally.
- Industrial appliances as provided in Section 509.2.5.
- Direct-vent systems as provided in Section 509.2.6.
- Appliances with integral vents as provided in Section 509.2.7.
- Mechanical draft systems as provided in Section 509.3.3 through Section 509.3.3.5.
- Ventilating hoods and exhaust systems as provided in Section 509.3.4 and Section 509.3.4.1. [NFPA 54:12.7.2(1)]
|ROOF PITCH||H (minimum) (feet)|
|Flat to 6/12||1.0|
|Over 6/12 to 7/12||1.25|
|Over 7/12 to 8/12||1.5|
|Over 8/12 to 9/12||2.0|
|Over 9/12 to 10/12||2.5|
|Over 10/12 to 11/12||3.25|
|Over 11/12 to 12/12||4.0|
|Over 12/12 to 14/12||5.0|
|Over 14/12 to 16/12||6.0|
|Over 16/12 to 18/12||7.0|
|Over 18/12 to 20/12||7.5|
|Over 20/12 to 21/12||8.0|
For SI Units: 1 inch = 25.4 mm, 1 foot = 304.8 mm
A Type B-W gas vent shall terminate at least 12 feet (3658 mm) in vertical height above the bottom of the wall furnace. [NFPA 54:12.7.2(3)]
All gas vents shall extend through the roof flashings roof jack, or roof thimble and terminate with a listed cap or listed roof assembly. [NFPA 54:12.7.2(6)]
A gas vent shall terminate at least 3 feet (914 mm) above a forced air inlet located within 10 feet (3048 mm). [NFPA 54:12.7.2(7)]
Where a vent passes through an insulated assembly, an approved metal shield shall be installed between the vent and insulation. The shield shall extend not less than 2 inches (51 mm) above the insulation and be secured to the structure in accordance with the manufacturer's installation instructions.