Exhaust Vent Clearance

How much clearance (vent height) your roof exhaust vent needs depends on the pitch of your roof and the climate zone you live in.

  • The applications listed below are for when Exhaust Vents are installed no more than 1 to 2 feet below the peak of the roof. 
    This rule does not apply for roofs under a 2/12 pitch. Roof vents for flat roofs are discussed further below.

If you have a 4/12 roof pitch or greater, you can have a low profile roof vent (1” 2” tall collar) in all climate zones 1 – 8.

At a 3/12 roof pitch you can have a 1” or 2” tall collar in zones 1, 2, 3.

Having a 3/12 roof pitch in zones 4, 5, 6, 7, 8 you will need a 4” tall collar.

For roof pitches 2/12 or less you will need a 4” tall collar in zones 1 and 2.

You will need a 6" tall collar for zones 3, 4 and an 8” tall collar for zones 5 and 6.

You will need an 11″ or 12” tall collar for zones 7 and 8.

Bear in mind, you can always use taller collars for additional clearance in warmer zones, but you can’t use shorter collars in colder zones when dealing with low slope roofs. Custom collar heights are available.

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