Furnace Flue Pipe Roof Clearance

Table of type b vent rooftop clearance requirements.

Furnace flue pipe roof clearance.

Clearance distances for chimneys that are 10 ft 3 1 m or more away from the roof ridge measured at the up roof side of the chimney. Clearance from combustibles ranging from 0 to 18 to 36 typically depending on the fuel type electric gas oil. Maximum horizontal section of the furnace water heater double wall vent pipe cannot be longer than 100 of the vertical vent pipe length. The top of the flue opening should be at least 10 ft 3 1 m away from any roof surface or other structure.

The pipes can be set in two ways. Trim back the wood shift the vent or. See the detailed b vent chimney rooftop clearance table below. 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.

There are several gas or oil fired heating furnace clearance distance types. 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. Transite generally requires 1 to 3 inches depending on various factors. Furnace vent pipe installation code gas furnace venting codes furnace exhaust pipe code furnace flue vent code gas furnace exhaust pipe regulations.

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. The top of the chimney should be at least two feet above anything within a ten foot radius of the chimney. In contrast modern high efficiency condensing furnaces exhaust much cooler gasses and need only plastic pipe materials such as pvc cpvc or abs for their exhaust vents some high efficiency furnaces also include a plastic pipe for intake area and all types. 9 is a typical clearance between a gas fired boiler or furnace flue connector and combustibles.

The 1992 vent sizing tables require that all type b gas vents terminate above the roof with a listed cap or listed roof assembly in accordance with the manufacturer s instructions. When compared to the natural vent this one is more flexible although it is also costlier. Inadequate fire clearance from combustibles may not be obvious until you open a door such as our client is pointing out in this photograph. Traditional gas fired forced air furnaces produce hot combustion exhaust gasses and therefore need metal vent pipes or chimneys.

Fire clearances required range from 6 to 36 depending on the equipment.