Administration and General Regulations
40%of exam
Plumbing Fixtures
17%of exam
Water Supply and Distribution
14%of exam
Sanitary Drainage
13%of exam
Plumbing Vent Requirements
7%of exam
Traps, Interceptors, and Separators
7%of exam
Storm Drainage
2%of exam
Quick Facts
- Exam IDs
- F25 | G25
- Credential
- Journeyman Plumber (ICC)
- Questions
- 70 multiple-choice
- Time
- F25 3 hours; G25 4 hours
- Code Basis
- F25 2015 IPC; G25 2018 IPC
- Pass
- 70%, PASS/FAIL only
- Fee
- $120
- Format
- Open book, Pearson VUE
- Retake
- 10-day wait
- Pass Rate
- Not published by ICC
Test Numbers
Ten feet, five psi, fifteen minutes
Water: 10 ft headAir: 5 psiBoth: 15 minutesMetal supply air: 50 psi
F25 vs G25
F25
- 2015 IPC
- 3-hour limit
- No grease slope clause
G25
- 2018 IPC
- 4-hour limit
- 1/4 in grease slope
Same outline, different edition
Exam Day Logistics
- F25
- 2015 IPC, 3 hours
- G25
- 2018 IPC, 4 hours
- Questions
- 70 four-option multiple-choice
- Passing score
- 70 percent, PASS or FAIL
- Retake wait
- 10 days after a failure
- Guessing penalty
- None; answer every question
- Calculator
- Basic non-programmable four-function only
- Allowed marks
- Ink notes, highlighting, attached tabs
- Prohibited
- Photocopies of copyrighted material
- Fuel gas
- Excluded; F28 adds gas
Edition Number Shift
Shower moved up, backwater valve moved down
417.4 to 421.4424.3 to 412.3715.1 to 714.1
Service vs Distribution Pipe
Water Service
- 160 psi at 73.4 F
- PVC permitted
- Buried outside structure
Hot Distribution
- 100 psi at 180 F
- CPVC, never PVC
- Inside the building
Cold buried vs hot inside
Must-Know Definitions
- Branch interval
- 8 ft stack vertical length
- Developed length
- Along centerline through fittings
- Building drain ends
- 30 in past exterior wall
- Stack vent
- Extension of the waste stack
- Vent stack
- Air-only vertical vent pipe
- Flood level rim
- Edge where receptacle overflows
- Critical level
- C-L mark on backflow device
- No C-L marking
- Bottom of device governs
- Soil vs waste stack
- Fecal matter vs liquid waste
Rough-In and Final Tests
- DWV water test
- 10 ft head, 15 min
- Top 10 feet
- Exempt from the head
- DWV air test
- 5 psi, 15 minutes
- Air test equivalent
- 10 in mercury column
- Plastic DWV piping
- Air test prohibited; water only
- Water supply test
- Working pressure, 15 minutes
- Air on metal supply
- 50 psi minimum allowed
- Final smoke test
- 1 in water column, 15 min
- Shower liner test
- 2 in water, 15 minutes
- AAV install timing
- Only after DWV test
Materials and Pressure Ratings
- PVC
- Water service only, never distribution
- CPVC
- Interior hot and cold distribution
- Water service rating
- 160 psi at 73.4 F
- Hot distribution rating
- 100 psi at 180 F
- Lead free pipe
- 0.25 percent weighted average
- Lead free solder
- 0.2 percent maximum lead
- PVC primer
- ASTM F656, purple colored
- Copper types
- K thickest, L medium, M thin
Supports and Protection
- PVC/ABS DWV horizontal
- 4 ft spacing
- PVC/ABS DWV vertical
- 10 ft spacing
- Copper 1-1/4 in horizontal
- 6 ft spacing
- Cast iron horizontal
- 5 ft, or 10 ft lengths
- Cast iron vertical
- 15 ft spacing
- Water pipe burial
- 6 in below frost line
- Burial floor
- 12 in below grade minimum
- Foundation penetration
- Sleeve two pipe sizes larger
Plan Reading and Math
- 1/4 in scale
- One inch equals four feet
- 1/8 in scale
- One inch equals eight feet
- Static head
- 0.433 psi per vertical foot
- 1 psi
- 2.31 feet of head
- 45-degree offset
- Travel equals run times 1.414
- Isometric drawing
- Shows vertical runs and vents
- Read off isometric
- DFU, trap arms, vent heights
2015 to 2018 Renumbering
- Shower compartment
- 417.4 becomes 421.4
- Shower opening
- 417.4.2 becomes 421.4.2
- Shower valve
- 424.3 becomes 412.3
- Backwater valve
- 715.1 becomes 714.1
- Chapter 4 order
- Resequenced alphabetically by fixture
- What changed
- Numbers moved, rules unchanged
Fixture Clearance Numbers
Fifteen to the wall, thirty apart, twenty-one ahead
15 in to wall30 in center to center21 in in front
Shower Valve vs Public Lavatory
Shower Valve
- 120 F maximum
- ASSE 1016 valve
- Limit stop at valve
Public Lavatory
- 110 F maximum
- ASSE 1070 device
- Tempered water required
Two limits, two devices
Fixture Clearances
- Centerline to wall
- 15 in minimum
- Centerline to centerline
- 30 in minimum
- Clear space in front
- 21 in minimum
- Shower area
- 900 sq in minimum
- Shower least dimension
- 30 in minimum
- Shower exception
- 25 in with 1,300 sq in
- Shower measure height
- Up to 70 in
- Shower door opening
- 22 in clear width
- Fixture outlet to weir
- 24 in vertical maximum
IPC vs WaterSense Flow
IPC Table 604.4
- Showerhead 2.5 gpm
- Lavatory 2.2 gpm
- Urinal 1.0 gpf
WaterSense or State
- Showerhead 2.0 gpm
- Lavatory 1.5 gpm
- Urinal 0.5 gpf
Code base vs amendment
IPC Flow and Flush Limits
- Showerhead
- 2.5 gpm at 80 psi
- Private lavatory faucet
- 2.2 gpm at 60 psi
- Public lavatory faucet
- 0.5 gpm at 60 psi
- Metering faucet
- 0.25 gallon per cycle
- Water closet
- 1.6 gallons per flush
- Urinal
- 1.0 gallon per flush
- 2015 vs 2018
- Identical flow and flush values
- 2.0, 1.5, 0.5 figures
- WaterSense or state amendment
Water Heater Safety
- T&P discharge size
- Full size of valve outlet
- Discharge termination
- 6 in maximum above floor
- Discharge end
- No threads, no valves
- Discharge routing
- Gravity, untrapped, one device
- Never connect to
- The drainage system
- Pan depth
- 1-1/2 in minimum
- Pan drain
- 3/4 in indirect waste
- Shower valve limit
- 120 F, ASSE 1016
- Public lavatory limit
- 110 F, ASSE 1070
AVB vs RPZ
AVB
- 6 in above rim
- No downstream valve
- Not continuous pressure
RPZ
- High hazard rated
- Continuous pressure allowed
- Backpressure and backsiphonage
Hazard and pressure decide
Backflow Device Picker
- High hazard, continuous pressure→RPZ assembly(ASSE 1013)
- Low hazard, pollution only→Double check assembly
- Hose bibb or sillcock→Hose connection vacuum breaker(Permanently attached)
- No downstream valve, intermittent→Atmospheric vacuum breaker(6 in above rim)
- Open receptor available→Physical air gap(Cannot fail mechanically)
- Static pressure over 80 psi→Pressure-reducing valve(Creates a closed system)
Water Service and Pressure
- Minimum service size
- 3/4 in diameter
- Sewer separation
- 5 ft compacted earth
- Sleeve alternative
- 5 ft each side of sewer
- Vertical alternative
- 12 in above sewer top
- PRV trigger
- Static pressure over 80 psi
- PRV standard
- ASSE 1003 with strainer
- 10 ft separation
- Utility rule, not IPC
RPZ vs Double Check
RPZ
- High hazard, contamination
- ASSE 1013 assembly
DCVA
- Low hazard, pollution
- Never on health hazard
Hazard class picks device
Minimum Fixture Supply Sizes
- Lavatory
- 3/8 in
- Water closet flush tank
- 3/8 in
- Kitchen sink
- 1/2 in
- Bathtub
- 1/2 in
- Shower, single head
- 1/2 in
- Hose bibb
- 1/2 in
- Urinal flushometer
- 3/4 in
- Water closet flushometer
- 1 in, the outlier
Backflow Device Rules
- Air gap size
- Twice the effective opening
- Air gap minimum
- 1 in above flood rim
- AVB height
- 6 in above flood rim
- AVB downstream valve
- Never permitted
- AVB pressure limit
- 12 hours in any 24
- RPZ
- High hazard, continuous pressure
- DCVA
- Low hazard, pollution only
- Hose bibb
- Permanently attached vacuum breaker
Slope Ladder
Quarter, eighth, sixteenth as pipe grows
2-1/2 in: 1/4 in3-6 in: 1/8 in8 in: 1/16 inGrease upstream: 1/4 in, G25
Air Gap vs Air Break
Air Gap
- Open space above rim
- Twice the effective opening
- Food equipment requires it
Air Break
- Pipe ends below rim
- Separation to trap seal
- Dishwasher may use it
Above rim vs below rim
Which Slope Applies
- Pipe 2-1/2 in or less→1/4 in per foot
- Pipe 3 in to 6 in→1/8 in per foot(Steeper always allowed)
- Pipe 8 in or larger→1/16 in per foot
- Upstream of grease interceptor→1/4 in per foot(G25 only, 2018 IPC)
- F25, upstream of interceptor→Table 704.1 slopes apply
- Trap arm 2 in or smaller→1/4 in per foot(Table 909.1 basis)
- Trap arm 3 or 4 in→1/8 in per foot(Table 909.1 basis)
DFU Values and Slopes
- Bathroom group
- 5 dfu, 1.6 gpf closet
- Water closet, private
- 3 dfu
- Water closet, public
- 4 dfu
- Lavatory
- 1 dfu
- Bathtub, shower, kitchen sink
- 2 dfu each
- Pipe 2-1/2 in or less
- 1/4 in per foot
- Pipe 3 in to 6 in
- 1/8 in per foot
- Pipe 8 in or larger
- 1/16 in per foot
- Upstream of grease trap
- 1/4 in per foot, G25
Air Gap or Air Break
- Food-handling equipment waste→Air gap(Air break not allowed)
- Potable clear-water waste→Air gap
- Commercial dishwashing machine→Air gap or air break
- Potable water storage tank→Air gap above overflow
- Pipe ends below flood rim→Air break(Separation to trap seal)
- Sizing the air gap→Twice the effective opening(No 1-in floor here)
Cleanouts, Sumps, Backwater
- Cleanout interval
- 100 ft, all pipe sizes
- Direction change
- Cleanout over 45 degrees
- Stack base
- Cleanout at the foot
- Drain meets sewer
- Cleanout near that junction
- Clearance, 6 in pipe
- 18 in in front
- Clearance, 8 in pipe
- 36 in in front
- Sewage sump pit
- 18 in wide, 24 deep
- Sump cover
- Gas-tight, removable, vented
- Discharge valve order
- Check valve, then full-open
- Ejector solids
- 2 in spheres with closets
- Backwater valve trigger
- Floor below upstream manhole cover
- Above that elevation
- Must bypass the valve
Which Cleanout Is Required
- Horizontal run over 100 ft→Cleanout at 100 ft intervals
- Direction change over 45 degrees→Cleanout at the fitting
- Base of a waste stack→Cleanout at stack base
- Building drain meets sewer→Cleanout near that junction
- Pipe 6 in or smaller→18 in clearance in front
- Pipe 8 in or larger→36 in clearance in front
- Backwater valve installed→Accessible cleanout for service
Trap Arm Ladder
Bigger trap arm buys a longer run
1-1/4 in = 5 ft1-1/2 in = 6 ft2 in = 8 ft3 in = 12 ft4 in = 16 ft
Vent Stack vs Stack Vent
Vent Stack
- Carries air only
- Required at 5 intervals
- Connects at stack base
Stack Vent
- Extends the waste stack
- Above highest drain connection
- Terminates through roof
Separate pipe vs extension
Vent Method Picker
- One fixture trap→Individual vent(Half the drain served)
- Two traps, one fitting→Common vent
- Bathroom group, one branch→Wet vent
- Battery of 2-8 fixtures→Circuit vent
- Island sink, no wall→Island fixture vent
- No roof penetration possible→Air admittance valve(One open vent required)
- Stack has 5 branch intervals→Vent stack required
Vent Sizing and Terminals
- Individual vent size
- Half the drain served
- Absolute minimum vent
- 1-1/4 in
- Vent over 40 ft
- Increase one nominal size
- Vent stack trigger
- 5 or more branch intervals
- Trap to vent, 1-1/4 in
- 5 ft maximum
- Trap to vent, 1-1/2 in
- 6 ft maximum
- Trap to vent, 2 in
- 8 ft maximum
- Trap to vent, 3 in
- 12 ft maximum
- Trap to vent, 4 in
- 16 ft maximum
- Terminal near opening
- 10 ft, or 3 ft above
- Promenade roof
- 7 ft above the roof
- Plain roof height
- Bracketed; jurisdiction fills in
- Frost closure areas
- Increase to 3 in diameter
Trap Seal Window
Two to four inches, never deeper
2 in minimum4 in maximumDeeper holds solidsShallower gets siphoned
Trap Rules
- Trap seal depth
- 2 in to 4 in
- Deeper than 4 in
- Holds solids, not self-scouring
- Prohibited traps
- S, bell, crown-vented, drum
- Also prohibited
- Moving-part and partition traps
- Building trap
- Prohibited, no exception
- Drum trap exception
- Solids interceptor or chemical waste
- Trap arm fall
- Not over one pipe diameter
- Fixture outlet to weir
- 24 in vertical, 30 horizontal
Interceptors and Separators
- Grease interceptor
- Receives FOG-bearing kitchen waste
- Water closet waste
- Never into grease interceptor
- Upstream slope, G25
- 1/4 in per foot minimum
- Upstream slope, F25
- Table 704.1 slopes govern
- Oil separator
- Garages and fuel facilities
- Oil separator venting
- Separate vapor vent required
- Sand interceptor
- Grit from wash-down areas
- Chemical waste
- Independent system, neutralize first
Storm Drainage Rules
- Storm to sanitary
- Prohibited under the IPC
- Combined public sewer
- Connect storm independently, trapped
- Design basis
- 100-year, one-hour rainfall
- Secondary drainage
- Required where parapets trap water
- Secondary inlet height
- 2 in above roof low point
- Subsoil drains
- Storm system, never sanitary
Common Traps
Flow rates did not change
IPC showerhead is 2.5 gpm ≠ 2.0 gpm is WaterSense
Urinal flush volume
IPC urinal is 1.0 gpf ≠ 0.5 gpf is an amendment
Lavatory faucet flow
Private lavatory is 2.2 gpm ≠ 1.5 gpm is an amendment
Renumbering is not rule change
417.4 became 421.4 ≠ Requirements stayed identical
Building traps are banned
Building trap prohibited outright ≠ Not the same as interceptor
Deeper trap seals are worse
Over 4 in holds solids ≠ 2 to 4 in only
Water service is not distribution
PVC for service only ≠ CPVC for interior hot
Sewer separation is 5 feet
IPC requires 5 ft ≠ 10 ft is a utility rule
Burial needs both numbers
6 in below frost line ≠ 12 in below grade
Cleanout clearance is IPC-specific
IPC uses 18 and 36 in ≠ The 12 in split is UPC
Vent stack vs stack vent
Vent stack carries air ≠ Stack vent extends waste stack
Bathroom group is discounted
Group equals 5 dfu ≠ Less than summing parts
Individual vent sizes off drain
Half the drain served ≠ Not the trap arm
Last Minute
- 1.70 questions, open book
- 2.F25 3 hours; G25 4 hours
- 3.Pass is 70 percent
- 4.Retake wait is 10 days
- 5.Administration is 40 percent
- 6.Slopes drop: quarter, eighth, sixteenth
- 7.Trap seal 2 to 4 in
- 8.Cleanouts every 100 ft
- 9.Air gap is twice opening
- 10.Showerhead 2.5 gpm, not 2.0
- 11.Water test: 10 ft, 15 min
- 12.No air test on plastic
- 13.Vent stack at 5 intervals
- 14.Storm never enters sanitary sewer
- 15.Building traps are prohibited
- 16.PVC service only; CPVC hot
- 17.Tab Tables 604.4, 704.1, 709.1
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