Plumbing

  • A valid permit and plans must be on-site R106.3.1
  • Plumbing systems shall be installed in a workman-like manner CPC 309.4

DWV/General

  • Sized properly and per plans CPC 703
    • ≤ 3 WC   =   3″ pipe
    • ≥ 4 WC   =   4″ pipe
  • Piping systems shall be designed and installed in conformance with sound limitations as required in CBC CPC 309.5
  • Dissimilar metals: dielectric union or 6″ brass nipple CPC 310.6 and 605.15
  • Corrugated pipe not allowed. “shall have a smooth and uniform surface” CPC 1003.1.1
  • Vents: > 6″ above the flood rim of the fixture served shall be approved drainage fitting CPC 905.3
  • ≥ 3 stories: cast iron (2 floors of non-CI ok) – residential only CPC 701.2.A
  • Fittings: application and direction – long sweep vs short CPC 706
  • Slope: 2% – ≥ 4″ 1% with BO approval CPC 708.1 & 718.1
  • Trench: Properly supported in trench – sand/clean dirt CPC 718.2
  • Cleanouts: Identify all required cleanouts (see cleanouts) CPC 707.4
  • Laundry stand-pipe: 18-30” above the trap weir and 6-18” above the finished floor CPC 804.1
  • Concealed slip joints: requires a 12” x 12” access panel CPC 402.10
  • Vent termination: ≥ 6” above the roof, ≥ 1’ above the vertical surface, 10’ from and 3’ above any opening, and 3’ from the property line CPC 906.1-7
  • ABS exposed to sunlight: must be protected (latex paint) and terminate into an approved flashing
  • 2” waste: shower, kitchen, laundry
    • The existing 1.5” waste can remain. Replace the fouling chamber with 2”. 1.5” trap to remain. BO
    • An existing 1.5” drain line ok as long as not modified. BO
  • WC: 2” vent CPC 904.1 & TABLE 703.2
  • Vent take-off: 6” above the flood rim unless prohibited by structural conditions (then, drainage fittings must be used), vent take-off above the center line with horizontal CPC 905.3
  • Grease interceptors: shall not be installed in food preparation areas. Including under concrete. CPC 1015.5

PEX CPC 604.1.2

  • Bending radius: 1/2″ = 6″—–3/4″ = 9″—–1″ = 11″
  • Leave slack to allow for expansion/contraction (expansion loops and offsets)
  • Secured: 32″ unsupported and 72″ supported
  • Keep hot and cold lines separate
  • Use sleeve through concrete
  • No joints allowed in slabs
  • 12″ vertical and 6″ horizontal from all heat sources
  • Water heater: Use a 12″ metal adapter at the gas water heater
  • Do not use oil-based caulks
  • Should not be exposed to UV light (natural or manmade)
  • Test with water, if available: > 55 psi for 15 min
  • Use approved bushing with metal studs – provide a 1/8″ larger hole if wood (bushing not required)
  • Protection: provide nail plates if passing through a stud within 2″ of the nailing surface

Trap Arm Lengths: (≥ 2 pipe diameters) CPC TABLE 1002.2

Size ____Min _____________Max

1.25”___2.5” _______________30”

1.5” ____3”________________ 42”

2”____ _4”_________________60”

3”_____ 6” _________________72”

4” _____8” ________________120”

>4” ___2 pipe diameters ____120”

Piping Support CPC table 313.3

ABS ___________4/10’

CI _____________5/15’ 10/15’ w/ 10’ pipe

Copper ≤ 1” _____6/10’

Copper ≥ 1.25” __10/10’  

PEX ____________2’6”

Steel pipe CPC 1210.2.4.1 

½” _________6’ 

0.75-1” _____8’

≥ 1.25” _____10’

Flow Rates

WC _________________1.28 ___CPC 411.2

Faucet _______________1.2 ___CPC 407.2.1.2

Shower Head _________1.8 ___CPC 408.2

Commercial Faucet ____0.5 ___CPC 407.2.1

Metering Faucet _______0.2 ___CPC 407.2.2.1

Kitchen Faucet ________1.8 ___CPC 407.2.1.1

Laundry Faucet _______1.8 ___CPC 407.2.1.1

DOMESTIC WATER PIPE INSULATION CPC 150.J.2

  • Insulate ALL hot wall lines CPC 609.12 
  • Insulate hot and cold water lines first 5’ from the water heater (tanked) 8’ for commercial
  • Insulate all hot water recirculation lines regardless of size

TESTING

  • Ground plumbing: 10’ head of water for 15 minutes CPC 712.2
  • DWV: fill to overflow at the roof vents CPC 712.2
  • Supply: full city water pressure for 15 minutes CPC 609.4
  • Air testing: no air testing on plastic pipe (gas pipe and PEX are exempt) CPC 712.1
  • Gas: 10 psi for 15 minutes CPC 1213.3 

HYDRONIC PRESSURE TEST CMC 1205

  • Test at 1.5 times the operating pressure but not < 100 psi for 30 min. You can now test with air CMC 1205.2
  • Air removal devices: up and downstream CMC 1212.1-11
  • Water hammer prevention required CMC 1201.3
  • Protection of potable water supply. Backflow preventer and must be identified CMC 1202
  • Pressure and safety devices for closed systems  CMC 1206
  • Temperature limiting device. < 140 degrees CMC 1207.3.1
  • Expansion tank required with closed systems CMC 1209

Cleanout Requirements CPC 707

  • Intervals > 100’ CPC 707.4
  • Each aggregate horizontal change of direction > 135° CPC 707.4
  • 2’ inside or outside of bldg, near bldg drain connection to bldg sewer (2-way)  CPC 707.4.4
  • ≤ 2” cleanout required ≥ 18” clearance in front CPC 707.9
  • >2” cleanout required ≥ 24” clearance in front CPC 707.9
  • Underfloor cleanout within 5’ from the access CPC 707.9
  • 4” cleanout within 5’ of the property line extended to grade (2-way) EBMUD
  • All kitchen sinks and urinals (san-t at p-trap is considered a cleanout) CPC 707.4 and BO

Cleanout Size CPC TABLE 707.1

Pipe Size ___Cleanout

1.5 __________1.5

2 ____________1.5

2.5 __________2.5

3 ____________2.5

≥ 4 __________3.5

Vertical Wet Venting CPC 908.1

Wet venting is limited to vert drainage piping receiving discharge from trap arms of 1 and 2 fixture unit fixtures that also serve as a vent not > 4 fixtures. 

The water closet and clothes washer standpipe shall not discharge into the vertical wet vent. (WC = 3 dfu, clothes washer standpipe = 3 dfu CPC table 702.1)

Wet-vented fixtures shall be w/in the same story; provided, that fixtures with a continuous vent discharging into a wet-vent shall be w/in the same story as the wet-vented fixtures.

No wet vent shall be > 6’ in length

Vert piping between 2 consecutive inlet levels shall be considered a wet-vented section. 

Each wet-vented section shall be increased 1 pipe size larger than the minimum of the upper fixture or the sum of the fixture units served by the wet-vented section in no case < 2”

Common vent sizing shall be the sum of the fixture units served but, in no case, < the min vent pipe size req for fixture served

Horizontal Wet Venting CPC 908.2

A bathroom group located on the same floor level shall be permitted to be vented by a horizontal wet vent. (This also excludes a back-to-back lavatory since the lavatories would be in separate bathroom groups.)

Bathroom Group- “Any combination of fixtures, not to  exceed 1 water closet, 2 lavatories, either 1 bathtub or 1 combination bath/shower, and 1 shower, and may include a bidet and an emergency floor drain.”  The definition for “bathroom” states: “A room equipped with a shower, bathtub, or combination bath/shower.”

Vent Connection CPC 908.2.1

The dry vent connection to the wet vent shall be an individual vent for the bidet, shower, or bathtub. 1 or 2 vented lavatory(s) shall be permitted to serve as a wet vent for a bathroom group

Only 1 wet vented fixture drain or trap arm shall discharge upstream of the dry-vented fixture drain connection (see figure 908.2.1(a-b)) 

Fixture Drain. The drain from the trap of a fixture to the junction of that drain with any other drain pipe 

Size CPC 908.2.2

The wet vent shall be sized based on the fixture unit discharged into the wet vent. The wet vent shall be ≥ 2” for ≤ 4 DFU and ≥ 3” for ≥ 5 DFU. The dry vent shall be sized per Table 702.1 and 703.2 based on the total fixture units discharging into the wet vent

Trap Arm CPC 908.2.3 That portion of a fixture drain between a trap and a vent

The vent pipe opening from the horizontal wet vent, except for the WC and similar fixtures, shall not be below the weir of the trap. (the lavatory(s) may serve as the wet vent, or shall be individually vented when not serving as the wet vent)

Water Closet CPC 908.2.4

The WC fixture drain or trap arm connection to the wet vent shall be downstream of the fixture drain or trap arm connections to the horizontal wet vent

Additional Fixtures CPC 908.2.5

Additional fixtures shall discharge downstream of the wet vent system and be conventionally vented. Only fixtures within the bathroom group shall connect to the wet-vented horizontal branch