IRC Plumbing Practice Test Questions And Answers
2025/2026
What is the minimum size of a water meter and service piping in inches
for a water supply system of 34 fixture units with a maximum
developed length of 200 feet. The water pressure of the system is 35
psi. - CORRECT ANSWER-1
Table AP201.1
What is the minimum sized trap that can be used for the drainage
system of a bathtub (with or without shower head and/or whirlpool
attachments)? - CORRECT ANSWER-1.5
Table P3201.7
A water heater pan drain must extend full-size and terminate over a
suitably located indirect waste receptor or must extend to the exterior
of the building and terminate not less than _____ inches and not more
than _____ inches above the adjacent ground surface. - CORRECT
ANSWER-6, 24
,P2801.6.2
A laundry tray waste line is permitted to connect into a standpipe for
automatic clothes washer drain. The standpipe must extend not less
than _____ above the trap weir and must extend above the flood level
rim of the laundry tray. - CORRECT ANSWER-30 inches (762 mm)
P2706.1.2.1
Clothes closets, linen closets and pantries not exceeding _____ in area,
with the smallest dimension not greater than 3 feet (915 mm) and
having wall and ceiling surfaces of gypsum board will not require fire
sprinklers. - CORRECT ANSWER-24 square feet (2.2 m2)
P2904.1.1
If a water closet can be removed to provide cleanout access, does that
fulfill the cleanout requirement of the code? - CORRECT ANSWER-No
P3005.2.3
,Appliances and equipment used for heating water or storing hot water
have to be protected by _____. - CORRECT ANSWER-pressure-relief
valve and temperature-relief valve or a combination pressure and
temperature-relief valve.
P2804.1
Where the fixture drains connect at different levels, the common vent
must connect as a _____ extension of the _____ drain. - CORRECT
ANSWER-vertical, vertical
P3107.3
The minimum air gap distance in inches for lavatories and other fixtures
with effective opening not greater than 1/2 inch in diameter that are
close to a wall is: - CORRECT ANSWER-1.5
Table P2902.3.1
In areas prone to flooding as established by the code, water supply
systems must be designed and constructed to prevent _____ of
floodwaters. - CORRECT ANSWER-infiltration
, P2602.2
When either a public water-supply or sewer system, or both, are not
available, _____, an individual water-supply or individual sewage-
disposal system, or both, must be provided. - CORRECT ANSWER-or
connection thereto is not feasible
P2602.1
_____ installed in a bathroom are not required to be installed within an
enclosure. - CORRECT ANSWER-direct-vent water heaters
M2005.2
For water supply systems used predominantly for flush tanks having a
water supply fixture unit load of 12, what is the comparable demand in
gallons per minute. - CORRECT ANSWER-16.0
Table P2903.6(1)
Test equipment, materials and labor must be furnished by the ______ -
CORRECT ANSWER-permittee
2025/2026
What is the minimum size of a water meter and service piping in inches
for a water supply system of 34 fixture units with a maximum
developed length of 200 feet. The water pressure of the system is 35
psi. - CORRECT ANSWER-1
Table AP201.1
What is the minimum sized trap that can be used for the drainage
system of a bathtub (with or without shower head and/or whirlpool
attachments)? - CORRECT ANSWER-1.5
Table P3201.7
A water heater pan drain must extend full-size and terminate over a
suitably located indirect waste receptor or must extend to the exterior
of the building and terminate not less than _____ inches and not more
than _____ inches above the adjacent ground surface. - CORRECT
ANSWER-6, 24
,P2801.6.2
A laundry tray waste line is permitted to connect into a standpipe for
automatic clothes washer drain. The standpipe must extend not less
than _____ above the trap weir and must extend above the flood level
rim of the laundry tray. - CORRECT ANSWER-30 inches (762 mm)
P2706.1.2.1
Clothes closets, linen closets and pantries not exceeding _____ in area,
with the smallest dimension not greater than 3 feet (915 mm) and
having wall and ceiling surfaces of gypsum board will not require fire
sprinklers. - CORRECT ANSWER-24 square feet (2.2 m2)
P2904.1.1
If a water closet can be removed to provide cleanout access, does that
fulfill the cleanout requirement of the code? - CORRECT ANSWER-No
P3005.2.3
,Appliances and equipment used for heating water or storing hot water
have to be protected by _____. - CORRECT ANSWER-pressure-relief
valve and temperature-relief valve or a combination pressure and
temperature-relief valve.
P2804.1
Where the fixture drains connect at different levels, the common vent
must connect as a _____ extension of the _____ drain. - CORRECT
ANSWER-vertical, vertical
P3107.3
The minimum air gap distance in inches for lavatories and other fixtures
with effective opening not greater than 1/2 inch in diameter that are
close to a wall is: - CORRECT ANSWER-1.5
Table P2902.3.1
In areas prone to flooding as established by the code, water supply
systems must be designed and constructed to prevent _____ of
floodwaters. - CORRECT ANSWER-infiltration
, P2602.2
When either a public water-supply or sewer system, or both, are not
available, _____, an individual water-supply or individual sewage-
disposal system, or both, must be provided. - CORRECT ANSWER-or
connection thereto is not feasible
P2602.1
_____ installed in a bathroom are not required to be installed within an
enclosure. - CORRECT ANSWER-direct-vent water heaters
M2005.2
For water supply systems used predominantly for flush tanks having a
water supply fixture unit load of 12, what is the comparable demand in
gallons per minute. - CORRECT ANSWER-16.0
Table P2903.6(1)
Test equipment, materials and labor must be furnished by the ______ -
CORRECT ANSWER-permittee
