Roof Vent Height Code

The 1992 vent sizing tables below and more recent codes all 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.

Roof vent height code.

The size of vent piping shall be determined from its length and the total number of fixture units connected thereto in accordance with table 703 2 the diameter of an individual vent shall be not less than 1 1 4 inches 32 mm nor less than one half the diameter of the drain to which it is connected. So only use. Quoting the irc model plumbing code. Slits in the product allow for air to flow into the attic.

Also see chimney height clearance code separate article that compares the b vent with other chimney types. In locations known for snow the vent pipe needs to be at least 51 mm 2 in in diameter and 305 mm inside an insulated area of a building before extending through the roof. Below are building code documents which you may download. Vents in these locations also should extend 610 mm 24 in above a roof.

Vent pipes shall terminate not less than 6 inches above the roof measured from the highest point where the vent intersects the roof. A drip edge vent is made of a corrosive resistant material that sticks out about three inches back from the roof edge and then bends downward over them. Organizations such as the nrca recommend against this roof vent style in cold climates because it can promote ice dams. Access draft stops and ventilation.

Plumbing code citations for plumbing vent or vent stack clearance distances. 2010 florida building code plumbing 904 1 roof extension. 12 4 1 extension above roofs.