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Plumbing Vent Height Above Roof (All States Covered)

The substances and odors carried in the air ejected by a plumbing vent are considered harmful to health and air quality. Thus, there are specific regulations for where and how plumbing vents terminate, including the height above a roof.

Height regulations are influenced by what the roof is used for and what state you are in due to weather factors. Some states have different requirements to suit these regional factors better, but most follow the guidelines set by the International Residential Code (IRC).


The IRC requires at least 6” above the roof or anticipated snow line/firewall, or 7′ above the roof if it is used for recreation, parking, or assembly. Only Connecticut, Delaware, Indiana, Maine, Michigan, Minnesota, Montana, New Hampshire, Ohio, Rhode Island, Vermont, and Wisconsin differ in some way.

Table of Plumbing Vent Heights According to State

Man fixing the flashing for the plumbing vent
StateHeightSectionCode
Alabama6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1Residential Code 2015 of Alabama
Alaska6” above roof OR
6” above firewall OR
7’ above roof (roof used as assembly or parking area)
Section 906.1 Section 906.3Uniform Plumbing Code 2018 of Alaska
Arizona6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2Residential Code for One- and Two-family Dwellings as amended by the city of Phoenix
Arkansas6” above roof OR
7’ above roof (roof used as assembly or parking area)
Section 903.12018 Arkansas Plumbing Code
California6” above rood OR
6” above firewall OR
7’ above roof (roof used as assembly or parking area)
Section 906.1 Section 906.3California Plumbing Code 2019
Colorado6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2Residential Code 2021 of Colorado
Connecticut12” above roof OR
7’ above roof (roof used as living space)
Section P3103.12015 IRC portion of 2018 CT State Building Code
Delaware12” above roof OR
7’ above roof (roof used as living space)
Section 903.12018 State of Delaware Plumbing Code
Florida6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.22020 FBC – Residential 7th edition
Georgia6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2Georgia State Minimum Standard One and Two Family Dwelling Code
Hawaii6” above roof OR
6” above firewall OR
7’ above roof (roof used as assembly or parking area)
Section 906.1 Section 906.3Uniform Plumbing Code 2018 of Hawaii
Idaho6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2International Residential Code 2021
Illinois6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2Residential Code 2018 of South Holland
Indiana12” above roof OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.22020 Indiana Residential Code
Iowa6” above roof OR
6” above firewall OR
7’ above roof (roof used as assembly or parking area)
Section 906.1 Section 906.3Uniform Plumbing Code 2021 of Iowa
Kansas6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2Residential Code 2018 of Kansas
Kentucky6” above roof OR
7’ above roof (roof used as living space)
Section 903.1  Plumbing Code 2018 of Kentucky
Louisiana6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1Residential Code 2015 of Louisiana
Maine2’ above roof OR
2’ above firewall OR
7’ above roof (roof used as living space)
Section 906.1 Section 906.3Uniform Plumbing Code 2021 of Maine
Maryland6” above roof OR
7’ above roof (roof used as living space)
Section 903.1Plumbing Code 2018 of Maryland
Massachusetts6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2International Residential Code 2021
Michigan1’ above roof OR
7’ above roof (roof used as living space)
Section P3103.12015 Michigan Residential Code
Minnesota12” above roof OR
7’ above roof (roof used as anything but weather protection)
Section 906.1 Section 906.32020 Minnesota Plumbing Code
Mississippi6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2Residential Code 2018 of Mississippi
Missouri6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1Residential Code 2015 of Missouri
Montana12” above roof OR
12” above firewall
Section 906.1 Section 906.3Uniform Plumbing Code 2021 of Montana
Nebraska6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2Residential Code of 2018 of Nebraska
Nevada6” above roof OR
6” projected snow line OR
7’ above roof (roof used as living area)
Section P3103.1.1 Section P3103.1.2Residential Code 2018 of Nevada
New Hampshire18” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2Residential Code for One- and Two-Family Dwellings of the State of New Hampshire
New Jersey6” above roof OR
7’ above roof (roof used for anything but weather protection or maintaining equipment)
Section 12.4.1New Jersey Plumbing Code 2018
New Mexico6” above roof OR
6” above firewall OR
7’ above roof (roof used as assembly or parking area)
Section 906.1 Section 906.32021 New Mexico Plumbing Code
New York6” above roof OR
6” above projected snow line OR
7′ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.22020 Residential Code of New York State
North Carolina6” above roof OR
6” above projected snow line
OR 7’ above roof (roof used as living space)
Section P3103.12018 North Carolina Residential Code
North Dakota6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2Residential Code 2018 of North Dakota
Ohio12” above roof OR
7’ above roof (roof used as living space)
Section 903.1Ohio Plumbing Code 2017
Oklahoma6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2Residential Code 2018 of Oklahoma
Oregon6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.22021 Oregon Residential Specialty Code
Pennsylvania6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2Residential Code 2018 of Pennsylvania
Rhode Island6” above roof OR
12” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.22021 Rhode Island State One and Two Family Dwellings
South Carolina6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2South Carolina Residential Code 2021
South Dakota6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2International Residential Code 2021
Tennessee6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living area)
Section P3103.1.1 Section P3103.1.2Residential Code 2018 of Tennessee
Texas6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living area)
Section P3103.1Residential Code for one- and two-family dwellings of the Texas Industrialized Housing and Building Program
Utah6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1Residential Code 2015 of Utah
Vermont6” to a maximum of 12” above roofSection 903.1Plumbing Code 2018 of Vermont
Virginia6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.22018 Virginia Residential Code
Washington6” above roof OR
6” above firewall OR
7’ above roof (roof used as assembly or parking area)
Section 906.1 Section 906.32018 Washington State Plumbing Code
West Virginia6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2Residential Code 2018 of West Virginia
Wisconsin8” above roof OR
7’ above roof (roof used as living area)
Pg. 44 Vent TerminalsWisconsin Drain and Vent System Design by the Wisconsin Department of Commerce
Wyoming6” above roof OR
6” above projected snow line OR
7’ above roof (roof used as living space)
Section P3103.1.1 Section P3103.1.2International Residential Code 2021

Explaining the Deviations From the IRC

Sections P3103.1.1 and P3103.1.2 of the IRC provide the basic regulations on plumbing vent termination that most states adhere to (e.g., Alabama). Most make minor amendments to the IRC or none at all.

The changes made by individual states make the minimum safety standards more applicable to local environmental conditions.

For example, the code for Hawaii, it doesn’t mention a snow line because snow doesn’t fall there.

Plumbing vent height in Hawaii

However, these codes do mention a firewall. One possible reason for this is that you want gas and air to be able to flow from and into the vent pipe easily and firewalls just out from the roof, and so they can block the free movement of air.

The snowier states account for the difference in vent height by specifying the vent should adhere to whichever is higher: the minimum requirement or the expected snow line.

The snow line comes in because it can block the vent, and a clogged vent causes all kinds of issues.

Wisconsin is the only state that doesn’t adhere to the IRC, as yet. However, their current code still bears resemblance to the regulations given by the International Code Council (ICC), and they have adopted some I-Codes.

Not all vents have to terminate through the roof. They can also go through the wall, soffit, or even terminate in the attic.

Sources

https://worldpopulationreview.com/state-rankings/snowiest-states

https://www.iccsafe.org/adoptions/country/usa/state/wisconsin

https://www.iccsafe.org/products-and-services/i-codes/2018-i-codes/irc/

https://dsps.wi.gov/Pages/Programs/Plumbing/Default.aspx

https://www.iccsafe.org/advocacy/adoptions-map/wisconsin/

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