Heads up: There are no amended sections in this chapter.
  1. All piping and fittings used in the vent system shall conform to requirements of Appendix A, Table A, "Approved Building Drainage/Vent Pipe" and "Approved Standards for Fittings".
  2. A system carrying corrosive waste shall be of approved materials as in Appendix A, Table A, "Approved Building Drainage/Vent Pipe". Vent piping shall be of the same material as the waste piping. (See Section 890.1310(b).)
  1. Design. A properly designed and installed venting system, in conjunction with the soil or waste system, is essential to protect trap seals and prevent siphonage, aspiration, or back pressure. The venting system shall be designed and installed to permit the admission or emission of air so that under normal and intended use the seal of any fixture trap shall never be subjected to a pneumatic pressure differential of more than a 1-inch water column. All fixture traps shall be protected by the use of a vent or venting system constructed in accordance with this Part.
  2. Installation. Fixture traps shall be protected by the appropriate method as follows: an individual dry vent, a wet vent, a common vent, a circuit or loop vent, an island vent, or a combination waste and vent system. A stack vent or vent stack shall be installed with a soil or waste stack whenever vents, relief vents or other branch vents are required. (See Appendix K.Illustration A.)
  3. Main Vent. Each building in which plumbing is installed shall have at least one main vent no smaller than 3 inches for each building drain installed. (See Appendix A.Table K and Appendix K.Illustration C.)
(Source: Amended at 38 Ill. Reg. 9940, effective April 24, 2014)
  1. Vent Terminals. Vents shall terminate independently above the roof to the outside atmosphere or shall be connected to another vent at least 6 inches above the flood-level rim of the highest fixture served by the vent. (See Appendix K.Illustration B.)
  2. Roof Extensions. Extensions of vent pipes through a roof shall be terminated at least 12 inches above the roof unless a roof is to be used for any purpose other than weather protection. If a roof is to be used for any purpose other than weather protection, the vent shall be extended at least 7 feet above the roof. (See Appendix K.Illustration D.)
  3. Flashings. Each vent terminal shall be made water-tight with the roof by proper flashing.
  4. Location of Vent Terminal. No vent terminal from a drainage system shall be directly beneath a door, window, overhang or other ventilating intake opening of the building, nor shall any vent terminals be within 12 feet horizontally of an opening or within 4 feet of a vertical obstruction unless it is at least 2 feet above the top of the opening. (See Appendix K.Illustration E.)
  5. Extensions Outside Building. No soil, waste or vent pipe extension (except for vent terminals as provided in subsections (b) and (d) of this Section() shall be located on the outside of a wall of any building, but shall be installed inside the building. Wet vents located within an exterior wall or in a wall adjacent to an unheated space shall be protected from freezing.
  6. Flag poles. Vent terminals shall not be used for the purpose of supporting flag poles, television aerials, or similar purposes.
  7. Vent Terminal Size. Each vent extension through the roof shall be a minimum of 3 inches in diameter and no smaller than the vent that it terminates. Vent terminals shall not be screened.
  8. Increasers. Changes in size or diameter of vent terminals shall be made by the installation of an increaser commencing at least 1 foot below the roof.
(Source: Amended at 38 Ill. Reg. 9940, effective April 24, 2014)
(Source: Repealed at 38 Ill. Reg. 9940, effective April 24, 2014)
  1. Grade. All vent and branch vent pipes shall be installed so as to drain back to the soil or waste pipe. (See Appendix K.Illustration F.)
  2. Vertical Rise. Where vent pipes connect to a horizontal soil or waste pipe, the vent shall be taken off above the center line of the soil or waste pipe, and the vent pipe shall rise vertically, or at an angle not more than 45 degrees from the vertical before offsetting horizontally or before connecting to the branch vent. Exception: Wet vent and floor drain vents may connect horizontally. (See Appendix K.Illustrations F, G and AA.)
  3. Height above Fixtures. The connection between a vent pipe and a vent stack or stack vent shall be made at least 6 inches above the flood-level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents or relief vents shall be at least 6 inches above the flood-level rim of the highest fixture served. (See Appendix K.Illustration H.)
  4. Heel or Side-Inlet Bend. A heel or side-inlet quarter bend or closet bend shall not be used as a dry vent when the inlet is placed in a horizontal position. (See Appendix K.Illustration I.) Heel or side inlet quarter or closet bends are permitted only in cases where the fixture connecting is vented. (See Appendix K.Illustration I.)
  5. All main vents or vent stacks shall connect full size at their base to the building drain or to the main soil or waste pipe at or below the lowest fixture branch. (See Appendix K.Illustration EE).
(Source: Amended at 38 Ill. Reg. 9940, effective April 24, 2014)
(Source: Repealed at 38 Ill. Reg. 9940, effective April 24, 2014)
  1. Distance of Trap From Vent. Each fixture trap shall have a protecting vent located so that the developed length in the fixture drain from the trap weir to the vent fitting is within the requirements in Appendix A.Table I. (See Appendix K.Illustration L.)
  2. Trap Weir. The vent pipe opening from a soil or waste pipe, except for water closets or fixtures with an integral trap, shall not be below the trap weir. (See Appendix K.Illustration N.)
  3. Crown Vent. No trap vent shall be installed within two pipe diameters of the trap weir. (See Appendix K.Illustration M.)
  4. Hydraulic Gradient. Fixture drains shall be vented within the hydraulic gradient between the trap outlet and the junction with another drain. The hydraulic gradient as applied to a gravity drain and its corresponding vent connection is interpreted as the grade line. (See Appendix A.Table I and Appendix K.Illustration N.)
  5. Different Level. If any stack has fixtures entering at different levels, the fixtures other than the fixtures entering at the highest level shall be vented in accordance with Section 890.1420(b).
  6. Fixture Trap Protection. Each fixture trap shall be protected by the appropriate method as follows: an individual dry vent, a wet vent, a common vent, a circuit or loop vent, an island vent or a combination waste and vent system.
  7. Mechanical Vents. Mechanical devices shall not be installed in lieu of vent piping.
  8. Trap Seal Loss. Trap seal that is subject to loss by evaporation shall be prevented. (See Section 890.410(f).)
(Source: Amended at 38 Ill. Reg. 9940, effective April 24, 2014)
  1. Individual Dry Vent is a single fixture trap vent only and shall not be installed as part of a wet vent.
  2. Common Vent. A vertical common vent may be used for two fixture traps if both traps connect with a vertical waste at the same level. (See Appendix K.Illustration O.) A horizontal common vent may be used for two fixture traps if both traps connect to the horizontal waste at the same point and the vent is located downstream of the fixture connection. The horizontal trap-to-vent distance shall comply with Appendix A.Table I. (See Appendix K.Illustration O and Appendix A.Table I.)
  3. Wet venting shall be installed in accordance with Section 890.1500.
  4. Circuit and loop venting shall be installed in accordance with Section 890.1520.
  5. Combination waste and vent systems shall be installed in accordance with Section 890.1590.
  6. Island vent systems shall be installed in accordance with Section 890.1600.
(Source: Amended at 38 Ill. Reg. 9940, effective April 24, 2014)
(Source: Repealed at 38 Ill. Reg. 9940, effective April 24, 2014)
  1. The following shall not be used to wet vent another fixture trap: water closets, washing machine connections, blowout urinals, or dishwashers.
  2. Two lavatories with 11/4-inch traps shall be considered a single fixture for the purpose of this Section.
  3. A vertical wet vent may be used for two fixtures set on the same floor level, but connecting at different levels in the stack, provided that the vertical wet vent/drain between the two traps is one pipe diameter larger than the upper fixture trap and that both drains conform to Appendix A.Table I. (See Appendix K.Illustration P.)
  4. A horizontal wet vent may be used for two fixtures set on the same floor level with one fixture connecting upstream of the other fixture on the horizontal line, provided that the horizontal wet vent/drain between the two fixtures is one pipe diameter larger that the upstream fixture trap. The vent connection shall be located between the traps, and each trap-to-vent distance shall be in accordance with Appendix A.Table I. (See Appendix K.Illustration Q.)
  5. A vertical/horizontal wet vent may be used for two fixtures set on the same floor level with one fixture connecting to the vertical stack and one fixture connecting to the horizontal line, provided that the wet vent/drain is one pipe diameter larger than the upper fixture trap and the drains conform to Appendix A.Table I. (See Appendix K.Illustration R.)
  6. A single bathroom group of fixtures, consisting of a water closet, lavatory and a bathtub, shower or floor drain, may be installed with the drain from a lavatory serving as a wet vent for a bathtub, shower or floor drain and for the water closet, provided that:
    1. Not more than four DFUs drain into a 2-inch diameter wet vent; and
    2. The horizontal branch is a minimum of 2 inches and connects to the stack at the same level as the water closet drain. The horizontal branch may also connect to the water closet bend. (See Appendix K.Illustration S.)
  7. Bathroom groups installed back-to-back consisting of two water closets, two lavatories, and two bathtubs, showers or floor drains may be installed without individual vents, provided that:
    1. The water closets are wasted to a proper vertical drainage fitting;
    2. The bathtubs, showers or floor drains connect to the stack at the same level as the water closets;
    3. The lavatories connect to the stack at the same level; and
    4. The vent is a minimum of 2 inches in diameter. (See Appendix K.Illustration T.)
  8. When bathroom groups are connected to the same soil stack, the waste pipe from one or two lavatories may be used as a wet vent for one or two bathtubs or showers, provided that:
    1. The wet vent and its corresponding extension to the vent stack are 2 inches in diameter;
    2. Each water closet is provided with an individual dry vent or vertical common vent; and
    3. The vent stack is sized as given in Appendix A.Table J. (See Appendix K.Illustrations U and V.)
  9. On the lower floors of a multi-story building, a water closet may be wet vented with a single lavatory in lieu of the requirements of Section 890.1470(h).
  10. Bathroom groups consisting of a water closet, lavatory, and bathtub or shower, connected to a stack by a separate branch, may wet vent the water closet and bathtub or shower with the lavatory, provided that:
    1. The water closet and bathtub/shower connect to the stack at the same level;
    2. The wet vent and its corresponding extension are a minimum of 2 inches in diameter; and
    3. A vent stack connects at or below the lowest fixture connection and is installed for a stack of this type. (See Appendix K.Illustration W.)
(Source: Amended at 38 Ill. Reg. 9940, effective April 24, 2014)
(Source: Repealed at 38 Ill. Reg. 9940, effective April 24, 2014)
  1. Battery Venting. A soil or waste branch to which two but not more than eight of the same type of floor outlets or fixtures, such as eight water closets, eight pedestal urinals, eight shower stalls or eight floor drains are connected in battery, may be vented by a circuit vent that shall take off from in front of the last fixture connection. Blowout type fixtures are prohibited. Lower floor branches serving more than three water closets shall be provided with a relief vent taken off in front of the first fixture connection. The horizontal branch for its full length to the farthest fixture opening shall be uniformly sized based on the total drainage fixture load as listed in Appendix A.Tables G, H and L. (See Appendix K.Illustration Y.)
  2. Dual Branches. When parallel horizontal branches serve a total of eight water closets (four on each branch), each branch shall be provided with a relief vent at a point between the two water closets most distant from the soil stack. The horizontal branch for its full length to the farthest fixture opening shall be uniformly sized based on the total drainage fixture load as listed in Appendix A.Tables G, H and L. Intermediate floor branches shall be provided with a relief vent taken off in front of the first fixture connection. If traps other than water closets discharge above the horizontal branch, each such trap shall be provided with a continuous vent. (See Appendix K.Illustration Z.)
  3. Vent Connections. When the circuit or relief vent connections are taken off the horizontal branch, the vent branch connection shall be taken off vertically from the top of the horizontal branch. (See Appendix K.Illustration AA.)
  4. Fixtures Back-to-Back in Battery. When fixtures are connected to one horizontal branch through a double wye, a sanitary cross in a vertical position, or a manufactured fixture carrier, a common vent for each two fixtures back-to-back shall be provided. (See Appendix K.Illustration BB.)
  5. Fixture Connections. Branch wastes and fittings for circuit vented fixtures shall be installed so that the fixture drain enters the side of the branch drain. (See Section 890.1320(i) and Appendix K.Illustrations Y and CC.)
  6. Circuit and Loop Vented Fixtures. For circuit and loop vented fixtures are installed in a multi-story building, a relief vent shall be provided at the base connection into the horizontal by connecting the vent stack, full-size, into or near the base of the soil stack, or by connecting the vent stack directly into the horizontal branch near the soil stack. The vent shall be carried full size. (See Appendix K.Illustration DD.)
(Source: Amended at 38 Ill. Reg. 9940, effective April 24, 2014)
An air pressure relief vent from a pneumatic ejector shall not be connected to the regular venting system but shall be connected separately to the outside atmosphere terminating as required in Section 890.1430 for vent extensions through roofs. Such relief pipe shall be of sufficient size to relieve air pressure inside the ejector to atmospheric pressure within ten (10) seconds, but shall not be smaller than one and one-half (1 1/2) inches in diameter.
Stacks with More Than Ten (10) Branch Intervals. Soil and waste stacks in buildings having more than ten (10) branch intervals shall be provided with a relief vent at each tenth interval, beginning with the top floor, or may be installed mid-way between the first and twentieth interval. The size of the relief vent shall be equal to the size of the vent stack to which it connects. The lower end of each relief vent shall connect to the soil or waste stack through a wye below the horizontal branch serving the floor, and the upper end shall connect to the vent stack through a wye at least 42 inches above the floor level.
  1. Offset Vents. Offsets less than 45 degrees from the horizontal in a soil or waste stack, except as provided in Section 890.1350, shall comply with subsections (b) and (c) of this Section. (See Appendix K: Illustration CC.)
  2. Separate Venting. The stack section below the offset and the stack section above the offset shall be vented as separate soil or waste stacks.
  3. Offset Reliefs. Offsets shall be vented by installing a relief vent as a vertical continuation of the lower section of the stack or as a side vent connected to the lower section between the offset and the next lower fixture or horizontal branch. The upper section of the offset shall be provided with a yoke vent. The diameter of the vents shall not be less than the diameter of the main vent, or of the soil or waste stack, whichever is smaller.
(Source: Repealed at 38 Ill. Reg. 9940, effective April 24, 2014)
Connection of Vents. Stack vents and vent stacks may be connected into a common vent header at the top of the stacks and then be extended through the roof to the outside atmosphere at one point. This header shall be sized as provided in Appendix A, Table K, the number of units being the sum of all units on all stacks connected thereto, and the developed length being the longest vent length from the interception at the base of the most distant stack to the vent terminal to the outside atmosphere, as a direct extension of one (1) stack.
  1. Size of Water Closet Vents. A water closet shall have at least a 2-inch vent.
  2. Size of Individual Vents. The diameter of an individual vent shall be at least 11/4 inches or at least half the diameter of the drain to which it connects, whichever is greater.
  3. Size of Relief Vents. The diameter of a relief vent shall be at least half the diameter of the soil or waste branch to which it is connected.
  4. Size of Circuit Vents. The diameter of a circuit vent shall be at least half the diameter of the horizontal soil or waste branch or the diameter of the vent stack, whichever is smaller. (See Appendix A.Table L.)
  5. Size of Vent Piping. The size of vent piping shall be determined based upon its length and the total number of drainage fixture units connected to the vent pipe as provided in Appendix A.Table K. No more than 20 percent of the maximum developed length as determined from Table K may be installed in the horizontal position. Vent piping serving floor drains shall be installed so as to minimize horizontal vent distances.
  6. Building Sub-drain Sump Pump Vent Sizes. Building sub-drain sump pump vents shall be sized in accordance with Appendix A.Table K.
  7. All vents pipes shall extend undiminished in size from the vent connection or stack cleanout through the roof to the outside atmosphere, or shall be reconnected with a branch vent, vent stack, or stack vent.
(Source: Amended at 38 Ill. Reg. 9940, effective April 24, 2014)
A combination waste and vent system consisting of floor and hub drains may be installed when structural conditions preclude conventional plumbing. Appurtenances delivering large quantities or surges of water shall not be discharged to a combination waste and vent.
  1. The waste piping and trap in a combination waste and end-vented (both ends) system shall be a minimum of 4 inches in diameter. The vents in the system shall be a minimum of 3 inches in diameter. Only one floor drain shall be connected to each branch of a combination waste and vent.
  2. A branch more than 15 feet in length shall be separately end vented. The minimum area of any vent installed in a combination waste and vent system shall be half the area of the drain pipe served.
  3. Sinks, lavatories and other fixtures that are roughed in above the floor shall not be permitted on a combination waste and vent system.
  4. Long mains shall be provided with additional relief vents located at intervals of every 100 feet. (See Appendix K.Illustration FF.)
(Source: Amended at 38 Ill. Reg. 9940, effective April 24, 2014)
  1. Traps for island sinks and similar equipment shall be roughed in above the floor and shall be vented by extending the vent as high as possible, but at least the drainboard height, and then returning it downward and connecting it to the horizontal sink drain immediately downstream from the vertical fixture drain. Back-to-back island vented fixtures shall meet the requirements of Section 890.1480(b).
  2. The returned vent shall be connected to the horizontal drain through a sanitary drainage fitting and shall be provided with a vent taken off the vertical fixture vent by means of a sanitary drainage fitting immediately below the floor and extending to the nearest partition and then through the roof to the outside atmosphere, or may be connected to other vents at a point at least 6 inches above the flood level rim of the fixture served. Drainage fittings shall be used on all parts of the vent below the floor level, and a minimum grade of 1/4 inch per foot back to the drain shall be maintained. The returned bend used under the drainboard shall be a one-piece fitting or assembly of a 45 degree, a 90 degree, and a 45 degree elbow in the order named. (See Section 890.1340 and Appendix K.Illustration GG.)
(Source: Amended at 38 Ill. Reg. 9940, effective April 24, 2014)
Linked Resources
P
P Premium Feature

This feature is included in the premium subscription. Visit the feature page to learn more.

Learn More
Code Compare
P
Code compare is not available for this code.
Bookmarks
P
P Premium Feature

This feature is included in the premium subscription. Visit the feature page to learn more.

Learn More
Amendment Styling
P
Amendment styling is not available for this code.