SynC™

SynC · SynC Standards

Sanitary Waste and Vent Piping

Rev7
IssuedOct 2, 2026
Contents

Revision history

Download
Build a datasheet from this standard Start a project with this standard already attached — one click, no setup.
Use in a project

1 Scope

NOTE This standard governs the gravity piping that carries sewage and liquid waste from every fixture, drain, and receptor in a building to the building sewer, and the vent piping that keeps air moving in that system so that every trap holds its seal. (1.1)
NOTE The scope begins at the outlet of each fixture trap, the outlet of each floor drain or receptor body, and the discharge connection of each sump or ejector, and ends five feet outside the foundation wall where the building drain becomes the building sewer. (1.2)
NOTE The following are governed elsewhere and are outside this standard: (1.3)
  • the building sewer and the site sanitary sewer beyond the five-foot point
  • storm and roof drainage piping, leaders, and roof drains
  • floor drains, area drains, cleanout bodies and plugs, fixture carriers, trap primers, trap seal protection devices, and backwater valves as products; this standard sets where they occur, how they connect, and the trap seal they carry
  • trench drains and the floor drains furnished with them as assembled systems
  • plumbing fixtures, fixture trim, and the exposed tailpiece and trap at a fixture
  • grease interceptors, and the material and slope of the grease waste pipe between the connected fixtures and the interceptor
  • sump pumps, sewage ejectors, their basins, controls, and the check and isolation valves on each pump
  • domestic water piping, including the supply to a trap primer
  • pipe insulation, acoustic lagging as a product, and the protective covers below accessible fixtures
  • firestop systems, pipe markers, and seismic bracing hardware
NOTE Laboratory and chemical waste piping, acid waste and its dilution or neutralization, and high-temperature process waste are not covered by this standard or by any other standard in this library, and a project with those discharges needs a separate specification for them. (1.4)
1.5 Pipe sizes, routing, invert elevations at connection points, and the location of every fixture, drain, receptor, and cleanout shall be as indicated on the plumbing plans, riser diagrams, and invert schedules.
NOTE This standard sets what the piping must be and how it must be installed and proven; the drawings set where it goes and how large it is, and the sizes on the drawings follow from the fixture-unit method of the adopted plumbing code rather than from any selection made here. (1.6)
NOTE Every drainage and vent material offered in this standard is permitted by at least one of the model plumbing codes, and Adopted Plumbing CodeAdopted Plumbing CodeParameterEach project supplies its own value.adopted-plumbing-code together with the Authority Having Jurisdiction determines which of them may be used on a given project, in which location, and at which sizes. (1.7)

2 Referenced Standards

2.1 Materials, components, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
2.2 Where the contract documents, the Authority Having Jurisdiction, or two referenced standards impose conflicting requirements, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
2.3 The adopted plumbing code shall take precedence over every other reference on any matter that code addresses directly.
Standard Title
IPC International Plumbing Code
UPC Uniform Plumbing Code
IBC International Building Code
ASCE 7 Minimum Design Loads and Associated Criteria for Buildings and Other Structures
ASTM A74 Cast Iron Soil Pipe and Fittings
ASTM A888 Hubless Cast Iron Soil Pipe and Fittings for Sanitary and Storm Drain, Waste, and Vent Piping Applications
CISPI 301 Hubless Cast Iron Soil Pipe and Fittings for Sanitary and Storm Drain, Waste and Vent Piping Applications
CISPI 310 Coupling for Use in Connection with Hubless Cast Iron Soil Pipe and Fittings for Sanitary and Storm Drain, Waste and Vent Piping Applications
ASTM C1277 Shielded Couplings Joining Hubless Cast Iron Soil Pipe and Fittings
ASTM C1540 Heavy Duty Shielded Couplings Joining Hubless Cast Iron Soil Pipe and Fittings
ASTM C564 Rubber Gaskets for Cast Iron Soil Pipe and Fittings
ASTM C1173 Flexible Transition Couplings for Underground Piping Systems
ASTM C1460 Shielded Transition Couplings for Use with Dissimilar DWV Pipe and Fittings Above Ground
ASTM D2665 Poly(Vinyl Chloride) (PVC) Plastic Drain, Waste, and Vent Pipe and Fittings
ASTM F891 Coextruded Poly(Vinyl Chloride) (PVC) Plastic Pipe with a Cellular Core
ASTM D2661 Acrylonitrile-Butadiene-Styrene (ABS) Schedule 40 Plastic Drain, Waste, and Vent Pipe and Fittings
ASTM D2564 Solvent Cements for Poly(Vinyl Chloride) (PVC) Plastic Piping Systems
ASTM F656 Primers for Use in Solvent Cement Joints of Poly(Vinyl Chloride) (PVC) Plastic Pipe and Fittings
ASTM D2235 Solvent Cement for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe and Fittings
ASTM D3138 Solvent Cements for Transition Joints Between Acrylonitrile-Butadiene-Styrene (ABS) and Poly(Vinyl Chloride) (PVC) Non-Pressure Piping Components
ASTM F714 Polyethylene (PE) Plastic Pipe (DR-PR) Based on Outside Diameter
ASTM B306 Copper Drainage Tube (DWV)
ASME B16.23 Cast Copper Alloy Solder Joint Drainage Fittings: DWV
ASME B16.29 Wrought Copper and Wrought Copper Alloy Solder-Joint Drainage Fittings: DWV
ASTM B32 Solder Metal
ASTM A53/A53M Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless
ASME B16.12 Cast Iron Threaded Drainage Fittings
ASME A112.3.1 Stainless Steel Drainage Systems for Sanitary DWV, Storm, and Vacuum Applications, Above- and Below-Ground
ASSE 1050 Stack Air Admittance Valves for Sanitary Drainage Systems
ASSE 1051 Individual and Branch Type Air Admittance Valves for Sanitary Drainage Systems
NSF/ANSI 14 Plastics Piping System Components and Related Materials
MSS SP-58 Pipe Hangers and Supports — Materials, Design, Manufacture, Selection, Application, and Installation
MSS SP-69 Pipe Hangers and Supports — Selection and Application
ASTM E84 Surface Burning Characteristics of Building Materials

3 Submittals

3.1 Action Submittals

3.1.1 The Contractor shall submit the following for review before any drainage or vent piping material is procured:
  • product data for each pipe and fitting furnished, giving the material, the ASTM, CISPI, or ASME designation, the weight class or wall construction, and the listing mark
  • product data for each coupling, gasket, solvent cement, primer, and transition fitting, giving the standard it conforms to and the pipe materials and sizes it is listed to join
  • product data for each air admittance valve, giving the ASSE listing, the size, and the fixture-unit rating
  • product data for each expansion joint and flexible connector, giving the movement it accommodates and the test pressure it is rated for
  • product data for the hangers, supports, riser clamps, and insulation shields, with the attachment method proposed for each structure type
  • product data for the acoustic lagging proposed where acoustic treatment is selected
  • shop drawings of any venting arrangement the Contractor proposes to change from that shown on the riser diagrams, with the change identified
Action Submittal Packagecheckbox
☐ Pipe and fitting product data
☐ Coupling, gasket, cement, and transition fitting product data
☐ Air admittance valve product data
☐ Expansion joint and flexible connector product data
☐ Hanger and support product data
☐ Acoustic lagging product data
☐ Venting change shop drawings
3.1.2 Piping installation shall not begin until the corresponding action submittals have been reviewed and returned.

3.2 Informational Submittals

3.2.1 The Contractor shall submit the following with, or before, the action submittals:
  • the coupling manufacturer's published torque for every hubless coupling type and size furnished
  • the thermal movement calculation for every plastic stack and every plastic horizontal run longer than 30 ft, with the expansion provision proposed for each
  • seismic restraint calculations sealed by a registered design professional, or the pre-approved restraint detail the Contractor intends to use with its listing identified
  • the training or certification record of every person who will make hubless, solvent cement, fusion, or stainless steel joints
  • the peak discharge rate of every item of equipment that drains to an indirect waste receptor, taken from the equipment submittals, with the receptor and drain each is assigned to
Informational Submittal Packagecheckbox
☐ Coupling torque values
☐ Thermal movement calculations
☐ Seismic restraint calculations or pre-approved detail
☐ Joining personnel training records
☐ Indirect waste discharge rate schedule

3.3 Closeout Submittals

3.3.1 The Contractor shall submit the following before the drainage and vent system is accepted:
  • as-built drawings recording the installed routing, the invert elevation at every cleanout and at the five-foot point, every change from the riser diagrams, and the location of every expansion joint and access panel
  • the test log for every rough-in test section and for the final test, recording the method, the head or pressure at the start and end of the hold, the result, and the witness
  • the record of every joint cut out and remade after a failed test, with the retest result
  • warranty documentation for each product carrying a manufacturer warranty, identifying the coverage period and the date coverage begins
  • a signed receipt from the Owner for the spare parts delivered
Closeout Submittal Packagecheckbox
☐ As-built drawings with inverts
☐ Test log
☐ Failed joint and retest record
☐ Warranty documentation
☐ Spare parts receipt

4 Quality Assurance

4.1 Installer Qualifications

4.1.1 Drainage and vent piping shall be installed by personnel holding the license the Authority Having Jurisdiction requires for that trade in the jurisdiction where the work is performed.
4.1.2 Hubless cast iron joints shall be made only by personnel who have been instructed in the coupling manufacturer's installation procedure, including the torque sequence, and the instruction record shall be on site before the first joint is made.
4.1.3 Heat fusion joints in polyethylene pipe shall be made only by personnel who have completed the pipe manufacturer's training for the fusion method and equipment being used.
4.1.4 The Contractor shall keep every torque wrench used on hubless couplings within the calibration interval the tool manufacturer publishes, and shall keep the calibration records on site.

4.2 Product Marking

4.2.1 Every length of pipe and every fitting shall carry a legible marking giving the manufacturer, the material designation, the size, the weight class or wall construction where the standard defines one, and the standard it conforms to.
4.2.2 Plastic pipe and fittings shall carry the NSF/ANSI 14 mark or the mark of another listing agency the adopted plumbing code recognizes for that material.
4.2.3 Material that does not carry the required markings shall not be incorporated into the work.

4.3 Inspection Hold Points

4.3.1 The rough-in piping and its test shall be made available for inspection by the Authority Having Jurisdiction before any portion of the system is concealed, insulated, backfilled, or encased.
4.3.2 Below-slab piping shall additionally be inspected on its bedding, before any backfill is placed over the pipe.
4.3.3 Work concealed before the applicable inspection is complete shall be uncovered at the Contractor's cost, and the concealing construction shall be reinstated at the Contractor's cost.

5 Drainage Design Basis

5.1 Pipe Sizing and Fixture Loading

5.1.1 Drainage and vent pipe sizes shall be as indicated on the drawings, and the Contractor shall report any size that is smaller than the fixture-unit method of the adopted plumbing code requires for the fixtures actually connected to it before that run is installed.
NOTE A fixture or drain added, relocated, or substituted after the drawings were issued changes the fixture-unit load on every run downstream of it, which is why the sizes are rechecked against what is actually being connected rather than taken as fixed. (5.1.2)
5.1.3 Pipe size shall not be reduced in the direction of flow.
5.1.4 No fixture, drain, or receptor shall be connected to a drainage pipe smaller than the minimum trap and trap arm size the adopted plumbing code assigns to that fixture.
5.1.5 Where the adopted plumbing code sets a minimum size for the building drain, for a stack serving a water closet, or for a vent stack, that minimum shall govern over any smaller size shown.

5.2 Horizontal Drainage Slope

5.2.1 Horizontal drainage piping shall be installed at a uniform slope in the direction of flow, not less than the minimum slope the adopted plumbing code assigns to its nominal size.
5.2.2 The design slope for horizontal drainage piping shall be as indicated in the datasheet, and where the code minimum for a given size is steeper than the datasheet value the code minimum shall govern.
Design Slope for Horizontal Drainage Pipingrange
in./ft
0.06250.1250.250.5
NOTE A steeper slope raises the velocity at low flow, which is what keeps solids moving in a run that sees a few fixtures at a time, and it costs invert elevation along the run, which on a long building drain is the ceiling height of the floor below or the depth of the trench; a slope at the code minimum for the size keeps the system shallow and relies on the pipe running near its design depth to carry solids, and the two codes differ on where that minimum sits, so the slope that is right for a project is a function of its pipe sizes, its run lengths, and the depth available at the outlet end. (5.2.3)
5.2.4 Horizontal drainage piping shall not be installed at a slope steeper than 1/2 in./ft unless the run is a vertical offset, because at a steep grade the liquid outruns the solids and strands them.
5.2.5 The slope of every horizontal run shall be verified with a level at each support before the run is concealed, and a run with a dip, a sag, or a reverse grade shall be rehung before it is tested.

5.3 Drainage Fittings and Changes of Direction

5.3.1 Every fitting in the drainage system shall be a drainage-pattern fitting with a recessed shoulder and a swept or 45-degree entry in the direction of flow.
5.3.2 Pressure-pattern tees, crosses, and fittings without a drainage shoulder shall not be used in drainage piping.
NOTE A pressure-pattern fitting leaves a square ledge at the branch where paper and solids catch, and a short-pattern tee used on a horizontal run points the branch flow across the main instead of along it, so the fitting pattern is where most chronic stoppages in an otherwise correctly sloped system begin. (5.3.3)
5.3.4 Changes of direction in drainage piping shall be made with the fittings the adopted plumbing code permits for that change: a sanitary tee only where a horizontal branch joins a vertical pipe, a wye or a combination wye-and-eighth-bend where a branch joins a horizontal pipe or where a vertical pipe turns to the horizontal, and a long-sweep bend or two 45-degree bends where a horizontal run changes direction.
5.3.5 A sanitary tee shall not be installed on its back or on its side to receive a horizontal branch, and a double sanitary tee shall not receive the discharge of fixtures whose trap arms are on opposite sides of a stack in the same horizontal plane unless the adopted plumbing code permits that arrangement for the fixtures served.
5.3.6 A heel-inlet or side-inlet quarter bend shall receive only a vent connection or a fixture the adopted plumbing code permits to connect at that inlet.

5.4 Stacks and Offsets

5.4.1 Each soil and waste stack shall run as straight as the building permits, and every horizontal offset in a stack shall be made with fittings no sharper than 45 degrees and shall be vented as the adopted plumbing code requires for an offset at that location.
5.4.2 An offset below the lowest branch connection shall be treated as a horizontal drain for slope, support, and cleanout purposes.
5.4.3 Horizontal branches shall not connect to a stack within the distance below a horizontal offset, or within the distance above the base of the stack, that the adopted plumbing code reserves for the pressure zone at those points.
NOTE The base of a stack and the inside of an offset are where the falling column of water decelerates and compresses the air ahead of it, and a trap connected into that zone is blown rather than siphoned; the code keeps branches out of those lengths for that reason, and a branch that lands there passes every test and still bubbles when the building is full. (5.4.4)
5.4.5 The base of each stack shall turn to the horizontal through a long-sweep fitting or two 45-degree bends, and shall be supported at the turn so that the stack carries none of the weight of the horizontal run.

6 Traps and Trap Arms

6.1 Fixture Traps

6.1.1 Every fixture, floor drain, and receptor connected to the drainage system shall discharge through a liquid-seal trap, and no fixture shall be double-trapped.
6.1.2 Every trap in the drainage system, including floor drain traps, shall carry a liquid seal of not less than 2 in. and not more than 4 in., except where the adopted plumbing code permits a deeper seal for a specific trap design.
6.1.3 Traps shall be self-scouring, shall have no interior partition, and shall be of a design the adopted plumbing code permits; drum traps, bell traps, S-traps, crown-vented traps, and traps with moving parts shall not be installed except where the adopted plumbing code permits one for a specific fixture.
6.1.4 Traps and tailpieces concealed within a cabinet, a pedestal, or a chase shall be of a material this standard permits for drainage piping at that location.
NOTE The exposed trap and tailpiece at a lavatory or sink are furnished under Plumbing FixturesPlumbing FixturesResolves to the current adopted revision.sync/plumbing-fixtures; this standard governs the trap from the point it is concealed, the trap arm, and every trap formed in the drainage piping. (6.1.5)
6.1.6 A fixture furnished with an integral trap, including a water closet and a floor drain body with a cast trap, shall not be provided with a second trap in the piping.
6.1.7 Each trap shall be installed level with respect to its seal, at the elevation the fixture rough-in requires, and as close to the fixture outlet as the fixture permits, within the vertical distance from the fixture outlet to the trap weir that the adopted plumbing code allows.

6.2 Trap Arms and Trap Seal Protection

6.2.1 The trap arm from each trap weir to the vent connection shall not exceed the developed length the adopted plumbing code allows for the trap arm size, and shall slope toward the vent connection at not more than the fall that keeps the vent opening above the trap weir.
NOTE A trap arm that falls more than one pipe diameter between the weir and the vent lets the vent opening drop below the weir, and the arm then acts as an S-trap and siphons on every full-bore discharge, which is what the length and fall limits exist to prevent. (6.2.2)
6.2.3 Where a trap arm shown on the drawings cannot be installed within the length and fall limits, the Contractor shall report the condition before the rough-in is concealed, and shall not relieve it by adding an air admittance valve, a crown vent, or a mechanical device unless the datasheet and the adopted plumbing code permit that device.
6.2.4 Floor drains and receptors that do not receive regular discharge shall be provided with a trap primer connection or a trap seal protection device furnished under Sanitary Drainage SpecialtiesSanitary Drainage SpecialtiesResolves to the current adopted revision.sync/sanitary-drainage-specialties, and the connection of the primer line to the trap shall be made under this standard.
6.2.5 The locations at which trap seal protection is provided shall be as indicated on the plumbing plans and the drain schedule.

7 Venting

7.1 Venting Method

7.1.1 The venting method for each fixture group shall be as indicated in the datasheet.
Venting Method for Fixture Groupsselect
Individual vent on every trap
Common vents for back-to-back fixtures with individual vents elsewhere
Wet venting of bathroom groups
Circuit venting of battery-installed fixtures
Combination waste and vent for floor drains and sinks
Single-stack venting with an engineered stack fitting system
Engineered venting designed by the Engineer of Record
Per drawings — the plumbing riser diagrams (deferred by default)
NOTE Individual venting puts a vent pipe on every trap and is the arrangement every code permits without conditions, at the cost of the most vent pipe and the most roof penetrations; common and wet venting let one vent serve several fixtures within the limits the code sets on their arrangement and load; circuit venting serves a battery of floor-outlet fixtures from one vent at the end of the branch and needs a relief vent when the branch is heavily loaded; combination waste and vent oversizes the drain so that it carries air above the flow and is limited to fixtures the code names; single-stack systems use aerator and deaerator fittings to control the flow in the stack and are permitted only where the adopted code recognizes the system; and engineered venting is sized by analysis rather than by table and is accepted by the Authority Having Jurisdiction on the Engineer of Record's documentation. (7.1.2)
7.1.3 The Contractor shall install the venting arrangement shown on the riser diagrams and shall not substitute one venting method for another without the Engineer of Record's written acceptance of the shop drawing showing the change.
7.1.4 Where the datasheet selects single-stack venting, the stack fittings, the stack and branch sizes, and the installation of the system shall be as the fitting system manufacturer publishes and as Adopted Plumbing CodeAdopted Plumbing CodeParameterEach project supplies its own value.adopted-plumbing-code permits for that system, and the system shall not be installed in a jurisdiction whose adopted code does not recognize it.
7.1.5 Where the datasheet selects engineered venting, the design documentation shall be submitted to the Authority Having Jurisdiction before the rough-in begins, and the system shall not be installed until that authority has accepted it.

7.2 Vent Sizing and Routing

7.2.1 Vent pipe sizes shall be as indicated on the drawings and shall be not less than the size the adopted plumbing code assigns for the drainage load served and the developed length of the vent.
7.2.2 Every vent shall rise vertically from the drain it serves to a point above the flood level rim of the highest fixture it serves before it runs horizontally, except where the adopted plumbing code permits a vent to run below that level for a specific method.
7.2.3 Horizontal vent piping shall slope back to the drain so that condensate and any water that enters the vent drains to the drainage system, and shall not form a pocket in which water can stand.
NOTE A vent that cannot drain fills with condensate at its low point, and a blocked vent gives no sign of itself until the traps it serves begin to siphon. (7.2.4)
7.2.5 Vent stacks shall connect to the drainage stack at or below the lowest branch connection, and stack vents shall extend the full size of the drainage stack to the roof, as the adopted plumbing code requires for the stack height served.
7.2.6 A vent header that collects several vent stacks before terminating shall be sized as the adopted plumbing code requires for the total load served, and shall be installed at or above the flood level rim of the highest fixture served.
7.2.7 Vent piping shall not be used to receive any drainage, and a drain shall not serve as a vent, except within a wet vent or a combination waste and vent installed as the venting method selected.

7.3 Vent Terminals

7.3.1 Each vent terminal shall extend above the roof by the height indicated in the datasheet, measured from the finished roof surface at the penetration.
Vent Terminal Height Above the Roofrange
in.
6710121824364860728496120
Derived — the minimum Adopted Plumbing CodeAdopted Plumbing CodeParameterEach project supplies its own value.adopted-plumbing-code requires, increased for snow accumulation where the roof is subject to it and for frost closure at Site Ambient Temperature MinimumSite Ambient Temperature MinimumParameterEach project supplies its own value.site-ambient-temperature-minimum (by default)
7.3.2 A vent terminal shall be located not less than the distance the adopted plumbing code requires from any door, operable window, air intake, or roof used for any purpose other than weather protection, and where that distance cannot be achieved the terminal shall extend above the opening by the height the code requires instead.
7.3.3 Where Site Ambient Temperature MinimumSite Ambient Temperature MinimumParameterEach project supplies its own value.site-ambient-temperature-minimum is below 0°F, every vent terminal shall be not less than 3 in. in diameter, and a vent smaller than that shall be increased in size inside the building at least 1 ft below the roof.
NOTE Moist air leaving a vent in severe cold freezes on the pipe wall and closes a small terminal from the inside in a single cold night, which is why the terminal is upsized where the roof is not warm enough to keep it open. (7.3.4)
7.3.5 Each vent terminal shall be flashed watertight with a flashing furnished under the roofing scope and set by that trade, and the vent pipe shall be supported so that the flashing carries none of its weight.
7.3.6 A vent terminal shall not be located under a roof overhang, within a parapet pocket, or where it discharges against a wall, and shall not be fitted with a cap, a screen, or any device that can collect frost or debris unless the adopted plumbing code requires one.

7.4 Air Admittance Valves

7.4.1 The use of air admittance valves shall be as indicated in the datasheet.
Air Admittance Valve Useselect
Not used
Individual and branch vents where the code permits
Individual, branch, and stack vents where the code permits
NOTE An air admittance valve admits air to the vent when the pressure in the drain falls and seals when it rises, so it replaces the vent pipe from that point to the roof; it saves the vent run and the roof penetration, it needs an accessible location and free air around it, it cannot relieve positive pressure and so does not replace every open vent in a system, it is a mechanical seal that can fail closed or stick open, and the two model codes differ on whether it is permitted at all, which is why the choice is made for the project rather than by the installer. (7.4.2)
7.4.3 Where the datasheet permits air admittance valves, they shall be used only where Adopted Plumbing CodeAdopted Plumbing CodeParameterEach project supplies its own value.adopted-plumbing-code and the Authority Having Jurisdiction permit them, at the locations indicated on the plumbing riser diagrams.
7.4.4 Air admittance valves serving individual or branch vents shall conform to ASSE 1051, and those serving stack vents shall conform to ASSE 1050.
7.4.5 Each air admittance valve shall be installed above the flood level rim of the highest fixture it serves by the distance the adopted plumbing code requires, in a location with free air around it, accessible for replacement, and not within a wall cavity that is closed without an access opening.
7.4.6 Where air admittance valves are used, not less than one vent in the system shall extend open to the outside air, sized as the adopted plumbing code requires for a system relieved through air admittance valves.

8 Drainage Piping Materials

8.1 Material Selection by Location

8.1.1 The material of drainage piping above the floor slab shall be as indicated in the datasheet.
Above-Grade Drainage Piping Materialselect
Hubless cast iron
Hub-and-spigot cast iron
PVC drain, waste, and vent pipe
ABS drain, waste, and vent pipe
Copper drainage tube
Galvanized steel pipe with drainage fittings
Stainless steel drainage pipe
8.1.2 The material of drainage piping below the floor slab and within the building footprint shall be as indicated in the datasheet.
Below-Slab Drainage Piping Materialselect
Hub-and-spigot cast iron
Hubless cast iron with heavy-duty couplings
PVC drain, waste, and vent pipe
ABS drain, waste, and vent pipe
Stainless steel drainage pipe
Polyethylene pipe, heat fused
8.1.3 The material of vent piping shall be as indicated in the datasheet.
Vent Piping Materialselect
The same material as the above-grade drainage piping
Hubless cast iron
Hub-and-spigot cast iron
PVC drain, waste, and vent pipe
ABS drain, waste, and vent pipe
Copper drainage tube
Galvanized steel pipe with drainage fittings
Stainless steel drainage pipe
NOTE Above the slab the material decision is mostly about what the pipe does to the building around it: cast iron damps the sound of the flow, does not move with temperature, and does not burn, and it is the heaviest to hang and the slowest to join; PVC and ABS cost and weigh less, are joined without a torque wrench, carry the sound of the flow through a partition, move enough with temperature that a long run needs an expansion provision, need a listed firestop system at every rated penetration, and are limited in plenums and in some occupancies by the adopted code; copper drainage tube is chosen where the pipe is exposed as a finish element or where space is tight, and is attacked by some wastes; galvanized steel with drainage fittings is a permitted material that survives impact in an exposed location and corrodes from the inside in service; and stainless steel is specified for corrosive wastes and washdown environments at the highest material cost. (8.1.4)
NOTE Below the slab the pipe is reached only by breaking the floor, so the choice there weighs a joint that stays tight under settlement against a wall that survives the backfill: a hub-and-spigot gasketed joint deflects without leaking, a hubless joint needs the heavy-duty coupling to hold its alignment without a hanger at each side of it, plastic pipe needs an embedment that supports it continuously, stainless steel is chosen where the soil or the waste is corrosive, and heat-fused polyethylene has no joints in the run and is permitted below the slab in the jurisdictions whose code lists it. (8.1.5)
NOTE A vent carries air and a trickle of condensate and never sees the waste, so a lighter or cheaper material is often chosen for it than for the drain, at the cost of a transition fitting at every point where vent and drain meet; keeping the vent in the drainage material removes those transitions and the second set of hangers and tools. (8.1.6)
8.1.7 Where Grease InterceptorsGrease InterceptorsResolves to the current adopted revision.sync/grease-interceptors selects the material of the grease waste pipe between the connected fixtures and the interceptor, the pipe standard, the joints, the hangers, the cleanouts, the traps, and the field tests of that pipe shall be as specified in this standard for that material.
8.1.8 The Engineer of Record shall confirm that every material selected is permitted by the adopted plumbing code for the service, the location, and the pipe sizes involved.

8.2 Hubless Cast Iron

8.2.1 Requirements in this article apply where hubless cast iron is selected for a location.
8.2.2 Hubless cast iron pipe and fittings shall conform to ASTM A888 or CISPI 301.
8.2.3 The weight class of cast iron soil pipe, hubless and hub-and-spigot alike, shall be as indicated in the datasheet.
Cast Iron Soil Pipe Weight Classradio
● Service weight
○ Extra-heavy weight
NOTE Extra-heavy pipe carries a thicker wall for the same nominal size, which buys crush resistance under a slab that sees vehicle loads and impact resistance where the pipe is exposed, at a higher weight to hang and a higher cost per foot. (8.2.4)
8.2.5 Cast iron pipe below a slab subject to vehicular loading shall be extra-heavy weight regardless of the datasheet selection.
8.2.6 The shielded coupling type for hubless cast iron above the slab shall be as indicated in the datasheet.
Hubless Coupling Type Above the Slabradio
● Standard shielded coupling to CISPI 310 and ASTM C1277
○ Heavy-duty shielded coupling to ASTM C1540
NOTE A standard coupling holds the joint watertight and relies on the hangers at each side of it to hold the pipe in line; a heavy-duty coupling adds a wider, thicker shield and more clamp bands, so that the joint itself resists deflection and the internal pressure of a tested or surcharged line, at roughly twice the cost per joint. (8.2.7)
8.2.8 Hubless joints below the slab shall be made with heavy-duty shielded couplings conforming to ASTM C1540.
8.2.9 Shielded couplings shall have a stainless steel shield, stainless steel clamp bands, and an elastomeric sleeve gasket conforming to ASTM C564.
8.2.10 Every hubless coupling shall be tightened with a calibrated torque wrench to the coupling manufacturer's published torque, in the sequence the manufacturer publishes, and the pipe ends shall butt against the center stop of the gasket with the coupling centered over the joint.
NOTE Couplings tightened by feel are the recurring source of leaks at test on hubless systems: an under-torqued band leaks at the test head and an over-torqued band strips or cuts the gasket, and neither is visible until water is in the line. (8.2.11)
8.2.12 Pipe ends shall be cut square, and a cut end with a burr, a spall, or an out-of-round condition that prevents the gasket from seating shall be recut.

8.3 Hub-and-Spigot Cast Iron

8.3.1 Requirements in this article apply where hub-and-spigot cast iron is selected for a location.
8.3.2 Hub-and-spigot cast iron pipe and fittings shall conform to ASTM A74.
8.3.3 The hub-and-spigot joint type shall be as indicated in the datasheet.
Hub-and-Spigot Joint Typeradio
● Compression gasket to ASTM C564
○ Caulked lead and oakum
NOTE A compression gasket joint is made by driving the spigot into a gasket seated in the hub, and it flexes without leaking; a caulked joint is made by packing oakum and pouring lead, and it is the joint some jurisdictions require to match an existing system and the joint chosen where the seal cannot depend on an elastomer. (8.3.4)
8.3.5 Compression gaskets shall be lubricated with the gasket manufacturer's lubricant, and the spigot shall be driven fully home in the hub with the joint in alignment.
8.3.6 Where caulked joints are furnished, the oakum shall be packed to the depth the pipe manufacturer publishes and the lead shall be poured in one pour and caulked to a dense finish flush with the hub.
8.3.7 A connection to existing lead-and-oakum piping shall be made with a transition coupling listed for the hub and spigot dimensions of the existing pipe, and an existing caulked joint shall not be disturbed to make the connection unless it is remade in full.

8.4 PVC and ABS Pipe

8.4.1 Requirements in this article apply where PVC or ABS drain, waste, and vent pipe is selected for a location.
8.4.2 PVC pipe and fittings shall conform to ASTM D2665, and the PVC wall construction shall be as indicated in the datasheet.
PVC Pipe Wall Constructionradio
● Solid wall Schedule 40 to ASTM D2665
○ Cellular core to ASTM F891
NOTE Cellular-core pipe has a foamed inner layer between two solid skins, weighs less and costs less than solid wall, and carries a lower crush rating and a lower impact resistance, which is why the adopted codes permit it above ground and restrict it below a slab in many jurisdictions. (8.4.3)
8.4.4 Cellular-core pipe shall not be installed below a slab, in a location subject to impact, or in any location where Adopted Plumbing CodeAdopted Plumbing CodeParameterEach project supplies its own value.adopted-plumbing-code does not permit it.
8.4.5 ABS pipe and fittings shall conform to ASTM D2661.
8.4.6 PVC joints shall be made with a primer conforming to ASTM F656 and a solvent cement conforming to ASTM D2564, and ABS joints shall be made with a solvent cement conforming to ASTM D2235.
8.4.7 A one-step PVC cement without a primer shall be used only where the cement is listed for that use and Adopted Plumbing CodeAdopted Plumbing CodeParameterEach project supplies its own value.adopted-plumbing-code permits a joint made without a primer.
8.4.8 PVC and ABS shall not be joined to each other by their own solvent cements, and a transition between them shall be made with a transition cement conforming to ASTM D3138 or a listed mechanical coupling.
8.4.9 Pipe shall be cut square, deburred, and dry-fit to full socket depth before cement is applied, and pipe that does not enter the socket to full depth shall not be forced.
8.4.10 Solvent cement joints shall be made at ambient temperatures within the range the cement manufacturer publishes, and shall be allowed to cure for the period the cement manufacturer publishes for the pipe size and the temperature before the line is moved, filled, or tested.
NOTE Cure time lengthens sharply as ambient temperature falls, and a joint that would be ready in an hour at 75°F can need several hours at 40°F. (8.4.11)
8.4.12 Plastic pipe shall not be threaded, and a threaded connection to plastic drainage pipe shall be made with a molded adapter fitting.
8.4.13 Plastic pipe installed before the building is closed in shall be shielded from direct sunlight, and pipe that has chalked or discolored from ultraviolet exposure shall not be installed.

8.5 Copper Drainage Tube

8.5.1 Requirements in this article apply where copper drainage tube is selected for a location.
8.5.2 Copper drainage tube shall conform to ASTM B306, and fittings shall be cast copper alloy drainage fittings conforming to ASME B16.23 or wrought copper drainage fittings conforming to ASME B16.29.
8.5.3 Copper joints shall be soldered with a lead-free solder conforming to ASTM B32, with the heat applied to the fitting, and the joint shall be cleaned of flux residue after soldering.
8.5.4 Copper tube shall be isolated from ferrous hangers and from contact with any dissimilar metal by a dielectric insert or a plastic-coated hanger.
8.5.5 Copper drainage tube shall not receive the discharge of a non-water urinal, of a water softener, or of any equipment whose discharge the tube manufacturer identifies as corrosive to copper.

8.6 Galvanized Steel Pipe

8.6.1 Requirements in this article apply where galvanized steel pipe is selected for a location.
8.6.2 Galvanized steel pipe shall conform to ASTM A53/A53M, Schedule 40, hot-dip galvanized, and fittings shall be galvanized cast iron threaded drainage fittings conforming to ASME B16.12.
8.6.3 Galvanized steel shall be installed only above ground, and shall not be installed below a slab, in soil, or in any location where Adopted Plumbing CodeAdopted Plumbing CodeParameterEach project supplies its own value.adopted-plumbing-code does not permit it.
8.6.4 Threaded joints shall be made with a thread compound compatible with the zinc coating, and the cut end of each pipe shall be reamed to full bore before assembly.
NOTE A pipe end not reamed after cutting leaves an internal burr at every joint, and in a drain that burr is the first thing paper catches on. (8.6.5)

8.7 Stainless Steel Drainage Pipe

8.7.1 Requirements in this article apply where stainless steel drainage pipe is selected for a location.
8.7.2 Stainless steel drainage pipe and fittings shall conform to ASME A112.3.1 and shall be joined by the push-fit gasketed joint or the mechanical coupling that standard covers.
8.7.3 The stainless steel grade shall be as indicated in the datasheet.
Stainless Steel Drainage Pipe Graderadio
○ Type 304
○ Type 316L
NOTE Type 304 resists the ordinary sanitary waste stream and the washdown chemicals of a commercial kitchen; the molybdenum in Type 316L raises the resistance to chlorides, which matters for brine discharge, for coastal soils below the slab, and for wastes carrying chlorinated cleaners. (8.7.4)
8.7.5 Stainless steel shall not be brought into contact with carbon steel tools, brushes, or wool, and tools used on stainless steel shall be dedicated to it.

8.8 Polyethylene Pipe

8.8.1 Requirements in this article apply where heat-fused polyethylene pipe is selected for the below-slab location.
8.8.2 Polyethylene pipe shall conform to ASTM F714 in the dimension ratio the pipe manufacturer publishes for gravity drainage, and fittings shall be the pipe manufacturer's molded or fabricated drainage fittings of the same material.
8.8.3 Joints shall be made by butt fusion or electrofusion using the equipment and the time, temperature, and pressure parameters the pipe manufacturer publishes, and every fused joint shall be allowed to cool undisturbed for the period the manufacturer publishes before the pipe is moved.
8.8.4 Polyethylene pipe shall be installed only where Adopted Plumbing CodeAdopted Plumbing CodeParameterEach project supplies its own value.adopted-plumbing-code lists it for the below-slab building drain, and the transition to the above-slab material shall be made with a transition fitting listed for both materials.

8.9 Transitions Between Materials

8.9.1 Every joint between two different drainage materials shall be made with a fitting or coupling listed for the two materials and the two outside diameters joined, and a transition shall not be made with a coupling intended for one material alone.
8.9.2 Transition couplings above ground shall conform to ASTM C1460 or shall be the listed adapter the pipe manufacturer publishes for the transition, and transition couplings below ground shall conform to ASTM C1173.
NOTE A hubless coupling slipped over a plastic pipe seals on an outside diameter it was not sized for, and it is the transition that leaks at the test or, worse, after the slab is poured. (8.9.3)
8.9.4 Where plastic drainage pipe connects to a cast iron hub, the connection shall be made with a listed hub adapter or a compression gasket listed for the plastic pipe's outside diameter.
8.9.5 A threaded connection between a metal drainage fitting and an item of equipment shall be made with a drainage-pattern fitting conforming to ASME B16.12 where the connection is galvanized steel, or with the adapter the equipment manufacturer publishes.

9 Special Discharges and Receptors

9.1 Indirect Waste Receptors

9.1.1 Every item of equipment that the adopted plumbing code requires to discharge indirectly, including water heater relief and drain-down discharge, water treatment brine and backwash, backflow assembly relief discharge, condensing appliance condensate, and the appliances that discharge through an air gap to a floor sink, shall discharge through an air gap or an air break to a receptor connected to the drainage system through a trap and a vent.
9.1.2 The receptor type at each indirect waste location shall be as indicated in the datasheet.
Indirect Waste Receptor Typeselect
Floor sink
Hub drain
Floor drain with funnel
Open standpipe
Service sink or mop basin
NOTE A floor sink has a basket strainer and a deep body and takes a splashing discharge at floor level without wetting the floor; a hub drain is an open pipe end raised above the floor and takes a piped discharge that is not splashed; a floor drain with a funnel receives a small continuous discharge such as condensate through the funnel without blocking the drain's grate; an open standpipe takes a hose discharge from a pumped appliance; and a service sink is used where the receptor doubles as a fixture, at the cost of a receptor that is occasionally occupied when the equipment discharges. (9.1.3)
NOTE The receptor body itself is furnished under Sanitary Drainage SpecialtiesSanitary Drainage SpecialtiesResolves to the current adopted revision.sync/sanitary-drainage-specialties; this standard sets that a receptor is provided, its type, the trap and vent it connects through, and the size of the drain serving it. (9.1.4)
9.1.5 The receptor outlet and the drainage pipe serving it shall be sized by the fixture-unit method of the adopted plumbing code for the peak discharge rate of every item that can discharge to the receptor at the same time, as scheduled in the informational submittals, and the drain shall be not less than 2 in.
9.1.6 The receptor shall be sized so that the peak discharge does not overflow its rim, and the Contractor shall report any receptor whose scheduled discharge exceeds its rated capacity before the receptor is set.
9.1.7 Where the discharge of a relief valve, a water treatment vessel, or a sump could flood the room if the receptor backed up, the receptor shall be located where a discharge is visible to operating staff and shall not be the only drain in the room.
NOTE Indirect waste piping from the equipment to the air gap is furnished under the standard governing that equipment; this standard begins at the receptor. (9.1.8)

9.2 Elevated-Temperature and Corrosive Discharges

9.2.1 Drainage piping that receives discharge at a temperature above 140°F, including relief valve discharge, boiler blowdown after a blowdown tank, and bulk discharge from a hot process, shall be cast iron, stainless steel, or another material its manufacturer rates for the discharge temperature, from the receptor to the point where the discharge is mixed with enough cooler flow to bring it below 140°F.
NOTE Thermoplastic drainage pipe is rated for intermittent discharge to 140°F, and a relief valve or a sanitizing rinse that runs hotter softens the wall at the receptor connection and deforms the first fitting downstream, which is why the hot run is carried in a metal that does not care. (9.2.2)
9.2.3 Where an elevated-temperature discharge cannot be cooled by mixing before it reaches the sewer, it shall be cooled to the temperature the sewer authority permits by a method the Engineer of Record directs, and the cooling device is not furnished under this standard.
9.2.4 The receptor and the drainage piping that receive the condensate of a condensing appliance without neutralization shall be of a plastic or stainless steel material not subject to attack by the condensate, from the receptor to the point where the condensate joins a flow that dilutes it.
NOTE Where Water HeatersCommercial Water HeatersResolves to the current adopted revision.sync/water-heaters furnishes a condensate neutralizer, the receptor downstream of the neutralizer may be of any material this standard permits for the location. (9.2.5)
9.2.6 The receptor and the drainage piping that receive the brine and backwash discharge of water treatment equipment shall be of a material not subject to attack by brine, and shall not be connected to a grease interceptor.
NOTE Brine discharge is intermittent, salty, and arrives at the regeneration flow rate of every vessel that regenerates at once, so the receptor serving a treatment train is sized for that combined flow under this standard and the material is chosen for chloride rather than for temperature. (9.2.7)

9.3 Non-Water Urinal Waste

9.3.1 The waste branch from each non-water urinal to the point where it joins a branch receiving a water-flushed fixture shall be of the material indicated in the datasheet, and that material shall be one its manufacturer publishes as resistant to undiluted urine.
Non-Water Urinal Waste Branch Materialselect
The drainage piping material selected for the location
PVC drain, waste, and vent pipe
Stainless steel drainage pipe
NOTE Undiluted urine deposits struvite and calcium salts on a rough or reactive wall and attacks copper and bare cast iron over time, so the branch from a non-water urinal is usually carried in a smooth plastic or stainless wall until it reaches the dilution of a flushed fixture; keeping the location's material simplifies the installation and is acceptable where that material is one the manufacturer publishes as resistant. (9.3.2)
9.3.3 The waste branch serving a non-water urinal shall be arranged so that a water-flushed fixture discharges into the branch upstream of the point where it joins the stack, where Adopted Plumbing CodeAdopted Plumbing CodeParameterEach project supplies its own value.adopted-plumbing-code requires that arrangement, and shall carry a cleanout at the urinal connection.
NOTE The trap seal method of the urinal itself is selected under Plumbing FixturesPlumbing FixturesResolves to the current adopted revision.sync/plumbing-fixtures; this standard governs the branch from the urinal outlet. (9.3.4)

9.4 Grease Waste Connections

9.4.1 Each fixture and appliance that discharges to a grease interceptor shall be trapped and vented under this standard, and the interceptor shall not serve as the trap for any fixture unless the interceptor is certified as providing a trap seal and the adopted plumbing code permits it.
9.4.2 The vent connections to each grease interceptor shall be made under this standard at the points Grease InterceptorsGrease InterceptorsResolves to the current adopted revision.sync/grease-interceptors requires, and the interceptor outlet shall be vented so that its discharge cannot siphon the interceptor or the traps of the fixtures it serves.
9.4.3 Water closets, urinals, and any fixture receiving human waste, and the brine and backwash discharge of water treatment equipment, shall bypass the grease interceptor and connect to the sanitary drainage system under this standard.
9.4.4 The drainage piping from the interceptor outlet fitting, or from the sampling point where one is furnished, to the building drain shall be of the material selected for the location under this standard.

9.5 Sumps and Ejectors

9.5.1 Gravity drainage from fixtures and drains below the level of the building sewer shall be carried under this standard to the inlet of a sump or ejector basin at the location indicated on the plumbing plans, entering the basin through the inlet hub the basin is furnished with.
NOTE The basin, the pumps, the controls, the check and isolation valves, and the discharge assembly up to its connection point are furnished under Sump And Sewage PumpsSump and Sewage PumpsResolves to the current adopted revision.sync/sump-and-sewage-pumps; this standard carries the gravity piping to the basin inlet and the gravity discharge piping from the connection point onward. (9.5.2)
9.5.3 The ejector discharge shall connect to the gravity drainage system through a wye fitting in the direction of flow at a point downstream of every gravity branch that could receive the pumped discharge by backflow, and the connection point shall be coordinated with Sump And Sewage PumpsSump and Sewage PumpsResolves to the current adopted revision.sync/sump-and-sewage-pumps before the basin is set.
9.5.4 A sewage ejector basin shall be vented through a vent of the size the adopted plumbing code requires for the basin, connected under this standard to the basin vent hub and carried to the vent system or to the outside air independently of any fixture vent.
NOTE A pumped discharge entering an undersized or wrongly placed connection pressurizes the gravity branches around it and blows the nearest trap on every pump cycle, which is why the connection is placed downstream of the branches and made with a wye rather than a tee. (9.5.5)

9.6 Backwater Protection

9.6.1 Where a fixture, a floor drain, or a receptor has a flood level rim below the elevation of the next upstream manhole cover of the public sewer, the drainage from it shall be protected against backflow by a backwater valve furnished under Sanitary Drainage SpecialtiesSanitary Drainage SpecialtiesResolves to the current adopted revision.sync/sanitary-drainage-specialties and installed under this standard in the branch serving only those fixtures.
9.6.2 Drainage from fixtures above that elevation shall not discharge through the backwater valve.
NOTE A backwater valve on the whole building drain closes against the surcharge and traps every upper-floor discharge behind it, which then backs up into the lowest fixtures the valve was meant to protect; placing it on the low branch alone protects those fixtures and leaves the rest of the building draining. (9.6.3)
9.6.4 Each backwater valve shall be installed where its cover is accessible for service, with a cleanout on its upstream side.

10 Cleanouts and Drain Connections

10.1 Cleanout Locations

10.1.1 Cleanouts shall be provided at the base of every stack, at the upper end of every horizontal drain not served by a stack or a fixture that gives rodding access, at every change in direction of a horizontal drain greater than 45 degrees, at intervals not exceeding 100 ft along horizontal drains, at the connection of every non-water urinal, and where the building drain leaves the building, as the adopted plumbing code requires and as indicated on the plumbing plans.
10.1.2 Each cleanout shall be the full size of the pipe it serves up to 4 in., and not less than 4 in. on larger pipe, and shall open in the direction of flow or at right angles to it.
10.1.3 Each cleanout shall be installed so that it can be opened and rodded without removing permanent construction, with the clearance in front of it that the adopted plumbing code requires for the cleanout size.
10.1.4 Cleanouts in finished floors shall be provided with an access cover at the finished surface, and cleanouts in walls or above ceilings shall be provided with an access panel or a wall cleanout plate.
NOTE Cleanout bodies, ferrules, plugs, access covers, and wall plates are specified in Sanitary Drainage SpecialtiesSanitary Drainage SpecialtiesResolves to the current adopted revision.sync/sanitary-drainage-specialties; this standard sets where cleanouts occur on the drainage piping and how they connect. (10.1.5)
10.1.6 A cleanout shall not be installed below the slab without a riser to the floor, and a cleanout riser shall be of the material selected for the below-slab location, extended to the finished floor through a sleeve.

10.2 Floor Drains and Drain Connections

10.2.1 Floor drains, floor sinks, hub drains, and area drains shall be installed at the locations indicated on the plumbing plans and the drain schedule, each connected to the drainage system through a trap of the depth this standard requires and a vent as the venting method selected.
NOTE The drain bodies, grates, strainers, sediment buckets, and clamping collars are furnished under Sanitary Drainage SpecialtiesSanitary Drainage SpecialtiesResolves to the current adopted revision.sync/sanitary-drainage-specialties or, for trench drains and the floor drains furnished with them, under Trench Drains And InterceptorsTrench Drains and Floor DrainsResolves to the current adopted revision.sync/trench-drains-and-interceptors; this standard governs the trap, the outlet connection, and the piping from the outlet. (10.2.2)
10.2.3 The drain outlet connection shall be made with the outlet type the drain body is furnished with, in the material this standard permits for the location, and a drain body with a caulked or gasketed outlet shall not be solvent cemented.
10.2.4 Each drain body shall be set so that its outlet connection, its trap, and the piping from it are supported independently of the slab or the deck, and so that the clamping collar, where one is furnished, is set in the waterproofing membrane under the direction of the trade installing that membrane.
10.2.5 The drainage connection to each shower drain, including the setting of the drain body's clamping ring in the shower pan membrane where the drain is furnished with one, shall be made under this standard with the drain body furnished under Plumbing FixturesPlumbing FixturesResolves to the current adopted revision.sync/plumbing-fixtures.
NOTE A drain set with its outlet piping hung from the slab reinforcement or bearing on the subgrade settles with the slab and pulls the outlet joint apart, and the leak runs under the floor for years before it shows. (10.2.6)

11 Hangers and Supports

11.1 Hanger Materials

11.1.1 Hangers and supports shall conform to MSS SP-58 and shall be selected and applied in accordance with MSS SP-69.
11.1.2 The hanger and support material shall be as indicated in the datasheet.
Hanger and Support Materialselect
Carbon steel, electroplated zinc
Carbon steel, hot-dip galvanized
Stainless steel
Copper-plated or plastic-coated carbon steel
NOTE An electroplated hanger is the ordinary interior hanger and is adequate wherever the pipe stays dry on the outside; hot-dip galvanizing is chosen for a parking level, a loading dock, a kitchen, or any location that is washed or wet; stainless steel is specified where the atmosphere is corrosive; and a copper-plated or plastic-coated hanger is what isolates copper tube from a ferrous hanger. (11.1.3)
11.1.4 Hangers on piping in a parking structure, a loading dock, a commercial kitchen, an unconditioned space open to the weather, or any washed-down space shall be hot-dip galvanized or stainless steel.
11.1.5 Plastic pipe shall be supported with hangers that provide a continuous bearing surface without sharp edges and that do not constrict the pipe.
11.1.6 Field-fabricated hangers, perforated strap, wire, and chain shall not be used to support drainage or vent piping.
11.1.7 Support attachments to the building structure shall be made only at points and by methods the structural drawings permit, and attachment methods shall be as indicated on the structural drawings and their attachment details.
11.1.8 Piping shall not be supported from another pipe, from ductwork, from conduit, from cable tray, from suspended ceiling framing, or from equipment.

11.2 Horizontal Support Spacing

11.2.1 The Contractor shall not exceed the following support spacings on horizontal piping.
Piping Material Nominal Size Maximum Horizontal Spacing
Hubless and hub-and-spigot cast iron All sizes Each side of every joint and 5 ft, or 10 ft where 10 ft lengths are used with a support at each joint
PVC and ABS pipe All sizes 4 ft
Copper drainage tube 1-1/4 in. and smaller 6 ft
Copper drainage tube 1-1/2 in. and larger 10 ft
Galvanized steel pipe All sizes 12 ft
Stainless steel drainage pipe All sizes 10 ft
Polyethylene pipe All sizes Continuous bedding below the slab
11.2.2 Support spacing shall be reduced where the adopted plumbing code, the pipe manufacturer, or the operating temperature requires a shorter span than the table gives.
NOTE A support at each side of a cast iron coupling keeps the joint from carrying a bending moment: the coupling is a watertight seal and not a structural connection, and a span load across it works the gasket loose with every fill of the line. (11.2.3)
NOTE Thermoplastics creep under sustained load, so an unsupported span that looks acceptable at installation sags progressively under the weight of the pipe and its contents, and a sag in a drain is a pocket that holds solids. (11.2.4)
11.2.5 A support shall be provided within 12 in. of each change of direction, at each side of every expansion joint and flexible connector, and at the base of every stack.
11.2.6 Horizontal piping shall be supported so that it holds the installed slope without sag between supports.

11.3 Vertical Support

11.3.1 Each stack shall be supported at its base and at every floor by a riser clamp bearing on the structure, and the clamp shall carry the stack's weight to the structure rather than to the horizontal piping below or to the branch connections at that floor.
11.3.2 Cast iron stacks shall be supported at intervals not exceeding 15 ft, and plastic, copper, and stainless steel stacks at every floor and at intervals not exceeding 10 ft.
11.3.3 Riser clamps on plastic stacks shall be installed so that the stack can move through the clamp at every floor except the anchor floor, with the anchor floor as the thermal movement calculation shows.
11.3.4 Stacks shall be installed plumb, and an offset shall be supported on each side of the offset.

11.4 Seismic Restraint

11.4.1 The scope of seismic restraint on the drainage and vent piping shall be as indicated in the datasheet.
Seismic Restraint Scopeselect
None because the piping falls below the threshold at which restraint is required
Piping above the code threshold size, restrained laterally and longitudinally
All drainage and vent piping regardless of size, restrained laterally and longitudinally
All drainage and vent piping, restrained laterally and longitudinally, with the additional bracing an essential facility requires
Derived — Seismic Design CategorySeismic Design CategoryParameterEach project supplies its own value.seismic-design-category, the component importance factor the project assigns to the drainage system, and the pipe size threshold Adopted Building CodeAdopted Building CodeParameterEach project supplies its own value.adopted-building-code and ASCE 7 Chapter 13 apply at that category (by default)
NOTE A gravity hanger carries load in one direction only, so in a seismic event the pipe swings on its rods until it strikes something or until a joint takes the bending; a hubless coupling has no bending strength and a solvent cement joint has no give, so the restraint scope follows the code threshold for the category and is widened where the building must stay in service after the event. (11.4.2)
11.4.3 Where seismic restraint is required, it shall be designed and installed in accordance with Vibration Isolation And Seismic RestraintVibration Isolation and Seismic RestraintResolves to the current adopted revision.sync/vibration-isolation-and-seismic-restraint, and the bracing shall not restrain the movement that the expansion provisions in this standard depend on.
11.4.4 Drainage piping crossing a building seismic joint shall be provided with a flexible connection accommodating the movement in every direction the structural drawings state.

12 Movement, Noise, and Penetrations

12.1 Thermal Movement of Plastic Piping

12.1.1 Where the thermal movement calculation shows a movement in a plastic stack or a plastic horizontal run greater than the movement its joints and supports accommodate, an expansion joint listed for drainage service, an expansion loop, or an offset with swing joints shall be provided for that run.
NOTE PVC and ABS move several times as much as cast iron for the same temperature change, and a stack that runs from a sunlit roof to a cool basement, or a horizontal run that receives hot discharge, accumulates that movement at the base fitting, where a solvent cement joint has no give at all. (12.1.2)
12.1.3 Expansion joints in drainage piping shall be installed with the pipe anchored on one side and guided on the other, located where they remain accessible, and rated for the test pressure of the section they are in.
12.1.4 Plastic stacks shall be anchored at the top or at one intermediate floor and guided at the others so that the movement is directed toward the expansion provision.

12.2 Acoustic Treatment

12.2.1 The acoustic treatment of drainage piping in the noise-sensitive locations indicated on the plumbing plans shall be as indicated in the datasheet.
Acoustic Treatment of Drainage Piping in Noise-Sensitive Locationsselect
None
Cast iron substituted for plastic in those locations
Field-applied acoustic lagging over the plastic pipe
Cast iron with acoustic lagging
NOTE A plastic drain beside a bedroom, a patient room, a classroom, or a conference room carries the sound of every flush through the partition; substituting cast iron in those locations damps the sound at the source and adds a transition at each end of the substituted run; a mass-loaded acoustic lagging over the plastic pipe achieves a comparable reduction without changing the material and adds a product to procure and install around every hanger; and lagging over cast iron is specified where the acoustic criterion of the room is stricter than bare cast iron meets. (12.2.2)
12.2.3 Where acoustic lagging is selected, it shall be a mass-loaded barrier with a decoupling layer, applied continuously over the pipe and fittings with lapped and sealed seams, carried through every hanger with an insert, and listed for a flame spread index not exceeding 25 and a smoke developed index not exceeding 50 when tested to ASTM E84.
12.2.4 Where cast iron is substituted for plastic in a noise-sensitive location, the substituted run shall extend through the full length of the partition or floor bounding the room and shall be isolated from the structure by resilient hanger inserts.

12.3 Plenums

12.3.1 Plastic drainage and vent piping shall not be installed within a return-air or supply-air plenum unless it is listed for that use, and where it is not listed the piping within the plenum shall be of a material this standard permits that is not plastic.
NOTE A plenum carries whatever burns in it to every room it serves, and the model codes treat a plastic pipe in a plenum as a fuel load unless it is listed for the exposure. (12.3.2)

12.4 Sleeves and Firestopping

12.4.1 Drainage and vent piping passing through a floor, a wall, a footing, or a foundation wall shall pass through a sleeve or a cored opening sized to leave clearance around the pipe, and the annular space shall be sealed against the passage of water at floors and foundation walls.
NOTE A pipe cast directly into concrete is restrained against thermal movement, abrades against the concrete, and cannot be replaced without breaking the structure. (12.4.2)
12.4.3 Piping passing through a fire-resistance-rated floor, wall, or shaft shall be firestopped with a system listed for the pipe material, the pipe size, and the assembly, installed in accordance with FirestoppingFirestoppingResolves to the current adopted revision.sync/firestopping.
NOTE A plastic stack through a rated floor is the case that needs the intumescent collar rather than a sealant, because the pipe itself burns away and leaves the opening it occupied. (12.4.4)
12.4.5 Openings through structural members shall be located, sized, and reinforced as the structural drawings show, and the Contractor shall not cut an opening the structural drawings do not show without the structural engineer of record's written direction.

12.5 Insulation of Drainage Piping

12.5.1 Drainage piping that is to be insulated for condensation control, and the waste and trap piping below accessible fixtures that is to be covered, shall be insulated in accordance with Plumbing InsulationPlumbing InsulationResolves to the current adopted revision.sync/plumbing-insulation, and the piping shall be installed so that the insulation and its vapor retarder can be applied continuously.

13 Buried and Below-Slab Piping

13.1 Bedding and Backfill

13.1.1 Below-slab and buried drainage piping shall be installed on a continuous bedding of the material indicated in the datasheet, shaped to the pipe barrel and free of rock, debris, and frozen material.
Below-Slab Pipe Bedding Materialradio
○ Undisturbed native soil shaped to the pipe
● Compacted sand or screened granular material
○ Controlled low-strength material
NOTE Native soil bedding costs nothing and is adequate where the subgrade is undisturbed and uniform, and it transmits every soft spot and every rock to the pipe; granular bedding gives uniform support under the barrel and is compacted around the haunches, and it needs a bell hole at every hub so that the pipe bears on its barrel; controlled low-strength material flows under and around the pipe and sets to a uniform support, is specified where the trench cannot be compacted or the pipe cannot be disturbed after placement, and restrains the pipe completely once set. (13.1.2)
13.1.3 The bedding thickness below the pipe barrel shall be as indicated in the datasheet.
Bedding Thickness Below the Piperange
in.
2346812
13.1.4 Bell holes shall be excavated at every hub and coupling so that the pipe bears on its barrel and not on the joint, and the bell hole shall be hand-filled with bedding after the joint is made and inspected.
13.1.5 Backfill shall be placed in lifts on both sides of the pipe at the same time and compacted by hand or with light equipment until the pipe has not less than 12 in. of cover, and mechanical compaction equipment shall not be operated directly over the pipe until that cover is in place.
NOTE Backfill placed on one side of a pipe before the other rolls the pipe off its grade, and a sag introduced that way is the one the slab is poured over. (13.1.6)
13.1.7 The minimum cover from the top of the pipe to the underside of the slab shall be not less than 6 in., and the cover below the slab shall otherwise be as indicated on the plumbing plans and the foundation details.
13.1.8 Where the trench bottom is softer or more variable than the soil conditions assumed in the structural drawings, the Contractor shall report the condition to the geotechnical engineer of record before installing any piping, and shall over-excavate and replace the unsuitable material as that engineer directs.
13.1.9 Where below-slab piping is installed below Seasonal High Groundwater ElevationSeasonal High Groundwater ElevationParameterEach project supplies its own value.seasonal-high-groundwater-elevation, the trench shall be dewatered until the backfill is placed, and empty piping shall be restrained against flotation.
13.1.10 Drainage piping shall be encased in concrete where indicated on the structural drawings and the foundation details, and the encasement shall be placed only after the piping has passed its rough-in test.
NOTE Encasing untested piping makes repair after a failed test a demolition job rather than a joint remake. (13.1.11)
13.1.12 Where drainage piping passes under a footing or within the zone of influence of a footing, it shall be sleeved or encased as the structural drawings show, and shall not be installed within that zone without a detail on those drawings.

13.2 Building Drain and Sewer Connection

13.2.1 The building drain shall extend to a point five feet outside the foundation wall at the location and invert elevation indicated on the plumbing site plan, and shall terminate there with a cleanout brought to grade and a transition fitting listed for the building sewer material.
NOTE The building sewer from that point is furnished under Sanitary Sewer SystemsSanitary Sewer Systems (Site)Resolves to the current adopted revision.sync/sanitary-sewer-systems within the site, and the five-foot point is also the boundary Site UtilitiesSite UtilitiesResolves to the current adopted revision.sync/site-utilities draws. (13.2.2)
13.2.3 The Contractor shall verify the invert elevation of the building sewer at the connection point before any horizontal drainage piping inside the building is installed, and shall report any elevation that does not permit the slope indicated in the datasheet from the farthest fixture.
NOTE An invert discovered too high after the building drain is bedded leaves no fix short of resetting every run upstream of it, so the elevation is checked at the outside end first. (13.2.4)
13.2.5 The building drain shall pass through the foundation wall in a sleeve or a wall pipe with clearance for the pipe to move, and the annular space shall be sealed against water entry.
13.2.6 The portion of the building drain outside the foundation wall shall be installed below Frost DepthFrost DepthParameterEach project supplies its own value.frost-depth or shall be protected against freezing by a method the Engineer of Record directs.
13.2.7 Where the building drain cannot reach the building sewer by gravity, it shall discharge to a sewage ejector as specified in this standard.

14 Installation

14.1 Workmanship

14.1.1 Piping shall be installed in accordance with the adopted plumbing code and the pipe manufacturer's published installation instructions for the material and joining method used, parallel or perpendicular to the building lines except where a slope is required.
14.1.2 Piping shall be installed clear of the openings of electrical equipment, and shall not be routed directly above a switchboard, a panelboard, a motor control center, a transformer, or an open electrical enclosure.
14.1.3 Drainage or vent piping shall not be installed within an elevator hoistway, within a machine room, or above an elevator pit except as the adopted building code and the elevator code permit.
14.1.4 Where the Contractor identifies a conflict that cannot be resolved by adjusting the routing within the slope and the allowances the drawings give, the Contractor shall request a routing change from the Engineer of Record before penetrating the structure, and shall not reduce a slope below the datasheet value or the code minimum to clear a conflict.
14.1.5 The Contractor shall coordinate the routing with the structural, mechanical, electrical, and fire protection work before installation begins, and gravity drainage shall take precedence in that coordination over systems that can be routed around it.

14.2 Fixture and Equipment Connections

14.2.1 Fixture waste outlet connections, trap arms, and vent connections shall be roughed in at the dimensions the fixture rough-in sheets give, and the Contractor shall coordinate those dimensions with Plumbing FixturesPlumbing FixturesResolves to the current adopted revision.sync/plumbing-fixtures before the rough-in is concealed.
14.2.2 Each fixture connection shall be made at the elevation that gives the trap arm its required slope and keeps the vent opening above the trap weir, and a fixture connection that cannot meet both shall be reported before the rough-in is concealed.
14.2.3 Drainage connections to equipment shall be made with a union, a flanged connection, or a coupling that permits the equipment to be removed without cutting pipe.
14.2.4 Connections to plumbing specialties furnished under Sanitary Drainage SpecialtiesSanitary Drainage SpecialtiesResolves to the current adopted revision.sync/sanitary-drainage-specialties and Plumbing SpecialtiesPlumbing SpecialtiesResolves to the current adopted revision.sync/plumbing-specialties shall be made in the material this standard permits for the location, and those specialties shall be included in the drainage system tests performed under this standard.

14.3 Protection During Construction

14.3.1 Open ends of installed piping shall be capped or plugged at the end of each work period, from the first length installed through the final test.
NOTE An open drain left overnight collects mortar, drywall mud, and debris that the first flow carries to the nearest fitting, and the stoppage that results shows up at occupancy. (14.3.2)
14.3.3 Installed piping shall be protected from damage by other trades, and temporary physical protection shall be provided where material handling, staging, or lift traffic passes an installed run.
14.3.4 Piping damaged during construction shall be cut out and replaced rather than repaired, unless the pipe manufacturer publishes a repair for the specific damage.
14.3.5 The Contractor shall not use the drainage or vent piping as a support, a lever, a lifting point, or a conduit for temporary services.

15 Identification

15.1 Drainage and vent piping in mechanical rooms, in accessible ceiling spaces, in chases with access, and wherever it is exposed shall be identified in accordance with Plumbing Piping IdentificationPlumbing Piping IdentificationResolves to the current adopted revision.sync/plumbing-piping-identification, and the legends, colors, sizes, and placement of the markers are as that standard specifies.
NOTE A sanitary stack and a storm leader are both black pipe in a chase, and the marker is what keeps a future tie-in off the wrong one. (15.2)

16 Testing

16.1 Test Method

16.1.1 Drainage and vent piping shall be tested after rough-in and before any pipe is concealed by construction, insulation, backfill, or encasement, by the method indicated in the datasheet.
Rough-In Test Methodradio
● Water test
○ Air test
NOTE A water test shows a leak as a wet spot at the joint and holds a slow leak visible for as long as anyone watches; an air test can be run in freezing weather and on a section whose base fitting cannot yet carry a column of water, and it shows a leak only as a gauge that falls, which then has to be found with soap. (16.1.2)
16.1.3 Plastic pipe shall not be air tested, and where an air test is indicated in the datasheet, plastic sections shall be water tested.
NOTE Plastic pipe fails under air pressure by fracture rather than by leak, and the stored energy of compressed air throws the fragments; a manufacturer's warranty on plastic pipe is void where the pipe has been air tested. (16.1.4)
16.1.5 Piping shall be tested in sections small enough that a failure can be located, and the extent of each section shall be recorded in the test log.
16.1.6 Below-slab piping shall be tested as its own section before any backfill is placed over the pipe, in addition to any test of the connected above-slab piping.

16.2 Water Test

16.2.1 For a water test, every opening in the section shall be plugged and the section shall be filled with water to a head not less than 10 ft above the highest joint in the section, except that the top section of a stack shall be filled to its vent terminal, and the head shall be held for not less than 15 minutes with no drop in level and no visible leakage.
16.2.2 Test plugs shall be rated for the head applied and shall be restrained so that they cannot be ejected.
16.2.3 Where a section has been filled from a water source that cannot be isolated during the hold, the fill shall be closed at a valve and the level watched at the open top of the section.

16.3 Air Test

16.3.1 For an air test, every opening in the section shall be plugged and the section shall be pressurized to not less than 5 psi, and the pressure shall be held for not less than 15 minutes with no drop shown on a gauge graduated in increments of not more than 0.1 psi.
16.3.2 Joints in a section under air test shall be checked with a soap solution where the gauge shows a loss.
16.3.3 The pressurizing source shall be fitted with a relief device set no higher than the test pressure, and the test area shall be cleared of personnel who are not conducting the test while the section is under pressure.

16.4 Final Test

16.4.1 After the fixtures are set and the traps are filled, the completed system shall be given a final test by the method indicated in the datasheet, and the test shall show no leakage at any trap, fixture connection, or joint.
Final Test Method After Fixture Settingselect
Fill and flush test with every trap sealed and the fixtures discharged together
Smoke test
Peppermint test
NOTE A fill and flush test discharges the fixtures floor by floor from the top down while every accessible joint below is watched, and it proves the fixture connections under flow; a smoke test fills the whole system with a dense smoke under a slight pressure and shows every open joint, every dry trap, and every missing cleanout plug at once, including the ones in the vent; and a peppermint test introduces oil of peppermint at the vent terminals and relies on an observer's nose to find the opening, which costs nothing in equipment and finds only the openings the observer passes. (16.4.2)
16.4.3 Where the adopted plumbing code or the Authority Having Jurisdiction requires a specific final test method, that method shall be used regardless of the datasheet selection.
16.4.4 Where a smoke or peppermint test is selected, every trap shall be filled before the test and the test shall not be run through a section whose plastic solvent cement joints have not fully cured.

16.5 Retesting and Records

16.5.1 A section that leaks or loses head or pressure shall be repaired by remaking the joint or replacing the pipe, and shall be retested by the same method until it passes.
16.5.2 A failed joint shall be cut out and remade, and shall not be sealed by caulking, by a wrap, by an external sealant, or by retightening a coupling that has already been torqued.
16.5.3 The cost of repair and retesting, including the cost of removing and reinstating any construction that conceals the section, shall be borne by the Contractor.
16.5.4 Tests shall be witnessed by the Engineer of Record's representative and, where the permit requires it, by the Authority Having Jurisdiction's inspector, and a test not witnessed shall be repeated.
16.5.5 Where the Contractor and the Engineer of Record disagree whether an observed loss of head or pressure constitutes a failure, the Engineer of Record shall make the initial determination.
16.5.6 The Contractor shall keep a test log recording each section, the date, the method, the head or pressure at the start and the end of the hold, the result, the witness, and every joint cut out and remade, and shall include the log in the closeout submittals.

17 Delivery, Storage, and Handling

17.1 Pipe, fittings, couplings, and gaskets shall be delivered in the manufacturer's packaging with the markings legible and intact, and deliveries shall be inspected on receipt.
17.2 Material that arrives unmarked, cracked, spalled at a hub or a spigot, out of round, or of a lighter weight class or wall construction than specified shall be rejected and returned.
17.3 Cast iron pipe that has been dropped shall be rung with a hammer, and a length that does not ring clear shall be rejected.
17.4 Pipe shall be stored off the ground on continuous dunnage, supported at intervals that prevent permanent sag, and with the ends protected.
17.5 Plastic pipe and fittings shall be stored out of direct sunlight and away from heat sources, and a length that has chalked, discolored, or deformed in storage shall not be installed.
17.6 Gaskets, sealing elements, solvent cements, primers, and lubricants shall be stored within the temperature range the manufacturer publishes, protected from ozone and sunlight, and shall not be used after the expiration date printed on the container.
17.7 Solvent cement that has thickened, gelled, or separated shall be discarded and shall not be thinned for use.
17.8 Material shall be handled without dropping, dragging, or bending, and shall not be used as a lever, a support, or a lifting point.

18 Warranty

18.1 The Contractor shall warrant the drainage and vent piping installation against defects in materials and workmanship, including joint failure, pipe failure, loss of slope, support failure, and leakage at any connection made under this standard, for the period indicated in the datasheet, beginning at the date of substantial completion.
Installation Warranty Periodrange
years
123510
18.2 The warranty shall cover the repair of the failed work, the restoration of any construction opened to reach it, and the repair of building finishes and Owner property damaged by the failure or by the water it released.
18.3 The warranty shall not cover a stoppage caused by material introduced into the system by the Owner's use, damage from freezing where the building heating system was not maintained in operation, or physical damage caused by others after the work was accepted.
18.4 Where a warranty repair is made, the repaired work shall carry a new warranty for the full original period from the date the repair is accepted, or for the remainder of the original period, whichever ends later.
18.5 The Contractor shall respond to a reported warranty failure that is actively releasing water or sewage within 24 hours of the report, and to any other reported warranty failure within 5 business days.
18.6 Manufacturer warranties for the products furnished shall be assigned to the Owner at substantial completion and included in the closeout submittal package.

19 Spare Parts

19.1 The Contractor shall deliver the spare parts indicated in the datasheet to the Owner before substantial completion.
Spare Parts to Be Deliveredcheckbox
☐ Two shielded couplings of each type and size installed
☐ Two compression gaskets of each size installed
☐ One air admittance valve of each size installed
☐ One expansion joint of each size installed
19.2 Spare parts shall be the same product, from the same manufacturer, as the item installed.
19.3 Spare parts shall be delivered in labeled packaging identifying the part and the quantity, stored where the Owner directs, and the Contractor shall obtain a signed receipt from the Owner and include it in the closeout submittals.

Edit this page

SynC Standards are reference material provided for informational purposes only and as a guide. They are not engineering, architectural, or legal advice and are not a substitute for the judgment of a licensed design professional. It is the responsibility of the user to determine the applicability of any standard to a specific project and to verify all requirements against the governing codes, manufacturer data, and project conditions. SynC does not render professional services and forms no professional relationship by publishing this content. Provided "as is," without warranty of any kind, including fitness for a particular purpose. See our Terms of Use for the complete terms. Moderation log.

This standard is published by SynC and licensed under Creative Commons Attribution-ShareAlike 4.0. You may share and adapt it, including commercially, provided you give credit, link to the license, indicate any changes, and license your adaptations under the same terms. Keep the attribution and notice below with any copy — it includes the warranty disclaimer the license requires you to retain.

Attribution & reuse notice — keep this with any copy:
"Sanitary Waste and Vent Piping." SynC Standards. Licensed under CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/). Source: https://synergyinconstruction.com/wiki/sync/sanitary-waste-and-vent-piping — reference material only; not professional engineering advice and provided without warranty. Verify against governing codes and have a licensed professional review before use.