IRC Plumbing Practice Test Latest 2026 Questions and
Correct Detailed Answers Already Graded A+
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
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
,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)
Correct Detailed Answers Already Graded A+
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
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
,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)
