Water Heater Vent Roof Clearance

Cut a hole through the roof and interior ceiling to accommodate the vent pipes.

Water heater vent roof clearance.

Atmospheric venting refers to a system in which exhaust from the water heater naturally rises out of the appliance s combustion chamber then travels up through a standard chimney style flue. Single wall vents should have a minimum of 6 inches of clearance and double wall sometimes called a b vent should have 1 inch minimum clearance. Single wall vent pipes cannot pass through a ceiling floor firewall or wall. Maximum horizontal section of the furnace water heater double wall vent pipe cannot be longer than 100 of the vertical vent pipe length.

Cut away the wood that s too close. Water heaters with power venting come with an electric blower fan often very quiet installed on top of the water heater and can have either vertical or horizontal vent ducts. In an attempt to maximize finished floor space when boxing off the water heater from the rest of the room people often don t leave enough clearance between the new wall framing and the vent pipes. Maintain the recommended air space clearance to combustible materials and building insulation.

See the detailed b vent chimney rooftop clearance table below. Furnace water heater vent pipe clearance double wall typical listed and labeled double wall vent pipe clearance to combustible materials is one inch but you should always check before installation. Single wall vents get very hot requiring a 6 in. Complete the vent pipe installation to the water heater s vent connector fittings.

Since the vent does not rely on the buoyancy of hot air it can be run horizontally to the outside of the house. In direct vent applications this clearance distance must be in compliance with local building codes the requirements of the fuel gas supplier for the heating appliance in use and the appliance manufacturer s instructions. Metal vents that are too close to wood or combustionable materials may cause the wood to burst into flames. For gas fired water heater vents.

6 minimum clearance from single wall vent pipe or flue vent connector to any combustible material. The manufacture even stamps this into the vent. If you are using a b vent typically a double walled air insulated vent for gas appliances typically you ll see a fire clearance stamped right into the metal of the chimney stating 1 inch minimum clearance to combustibles as you ll see in this photo. Except for flat and very low slope roofs such as those listed in the table below b vents should be at least two feet above the roof surface as well.

For non direct vent applications that is side wall venting only the required clearance is 7 feet.