2024 Residential Plans Examiner – Practice Quiz (Untimed)

2024 Residential Plans Examiner (R3) (Untimed)

60 Questions

2 Hours

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1. What is the minimum required headroom for a stairway?

A) 7 feet

B) 6 feet 6 inches

C) 7 feet 6 inches

D) 6 feet 8 inches

2 / 60

2. When more than one ampacity could apply to a circuit length, which value must be used?

A) Any of these

B) The average value

C) The lowest value

D) The highest value

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3. What must be included on the label of a fuel-burning unit?

A) Voltage, amperage, and type of refrigerant

B) Fuel cost estimate and maintenance schedule

C) Manufacturer’s service hotline

D) Type of fuel, hourly rating in Btu/h (W), and required clearances

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4. For a single-family dwelling, service conductors rated 100–400 amperes must have an ampacity of at least what percentage of the service rating?

A) 90 percent

B) 100 percent

C) 75 percent

D) 83 percent

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5. Plasticized polyvinyl chloride (PVC) sheets used for shower lining must meet the requirements of which ASTM standard?

A) ASTM D4551

B) ASTM D5000

C) ASTM D4068

D) ASTM D3309

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6. When an 8 AWG copper grounding electrode conductor is used, how must it be protected?

A) It must be encased in rigid metal conduit or other approved raceway types

B) It must be buried at least 24 inches deep

C) It requires no protection

D) It must be installed in ferrous metal raceway only

7 / 60

7. When must roof framing members and ceiling joists be provided with lateral support at points of bearing?

A) When installed over exterior walls

B) When the depth-to-thickness ratio exceeds 5 to 1

C) When span exceeds 10 feet

D) When installed in truss assemblies

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8. What is the minimum thickness for a concrete slab-on-grade for habitable spaces?

A) 3 inches

B) 3.5 inches

C) 4 inches

D) 2 inches

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9. What type of gas is prohibited for use as a test medium during pressure testing?

A) Carbon dioxide

B) Air

C) Nitrogen

D) Oxygen

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10. Electrical outlets serving the sump pump system must meet the requirements of which chapters?

A) Chapters 34 through 43

B) Chapters 1 through 10

C) Chapters 11 and 12

D) Chapters 29 and 30

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11. What is the maximum height of the bottom of the clear opening above the floor for an emergency escape opening?

A) 32 inches

B) 40 inches

C) 44 inches

D) 36 inches

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12. What is the minimum tread depth for residential stairs?

A) 8 inches

B) 9 inches

C) 10 inches

D) 11 inches

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13. What is the minimum square footage required for a habitable room?

A) 120 square feet

B) 50 square feet

C) 70 square feet

D) 150 square feet

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14. What is the minimum required guard height for a residential balcony?

A) 48 inches

B) 30 inches

C) 42 inches

D) 36 inches

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15. What determines the length of a braced wall line according to the IRC?

A) The sum of all braced panels on the same floor

B) The distance from the nearest load-bearing support

C) The distance between its ends, defined by perpendicular braced wall lines or exterior walls

D) The total length of all wall segments in a single direction

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16. How far must the galvanized metal tie extend beyond the opening when reinforcing a notched or drilled top plate?

A) 12 inches

B) 6 inches

C) 3 inches

D) 8 inches

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17. What is the main purpose of equipotential bonding around permanently installed pools, spas, and hot tubs?

A) To provide a path for lightning strikes

B) To reduce voltage gradients in prescribed areas

C) To improve grounding resistance

D) To prevent corrosion of metallic equipment

18 / 60

18. Which of the following tub installations allows a receptacle to be installed within the designated zone of the tub?

A) Hydromassage bathtub

B) Soaking bathtub

C) Portable bathtub insert

D) Walk-in bathtub

19 / 60

19. When using stay-in-place forms for concrete walls, what condition allows self-consolidating concrete to be placed without internal vibration?

A) If the slump is 8 inches or greater and specifically designed for placement without vibration

B) If the exterior wall is laterally braced during placement

C) If the reinforcement spacing exceeds 6 inches

D) If approved mortar is used with the concrete

20 / 60

20. What is the minimum thickness required for C-shaped bearing stiffeners when the joist is carrying a load-bearing wall above?

A) 33 mil (0.84 mm)

B) The same thickness as the wall stud above

C) One designation thickness greater than the joist

D) 43 mil (1.09 mm)

21 / 60

21. What is the minimum required size of a wet vent pipe if the fixture unit load discharging to the wet vent is 10 d.f.u.?

A) 2 inches.

B) 3 inches.

C) 1 1/2 inches.

D) 2 1/2 inches.

22 / 60

22. What is the required flow pressure (psi) for a lavatory outlet?

A) 4

B) 5

C) 8

D) 20

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23. Water-resistant gypsum backing board shall not be installed over which type of vapor retarder in a shower or tub compartment?

A) Class III

B) Class IV

C) Class I or II

D) Class II or III

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24. Where must a draft hood be located in relation to combustion air openings?

A) In the attic space above the appliance

B) Adjacent to the flue termination point

C) In the same room or space

D) In a separate ventilated enclosure

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25. For a plain masonry foundation wall with 9 feet of unbalanced backfill, 9 feet of unsupported wall height, and GW soil, what is the minimum wall thickness required?

A) 10 inches grouted

B) 12 inches grouted

C) 8 inches grouted or 10 inches solid

D) 6 inches solid

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26. What is the required minimum width of an exterior exit door landing?

A) 36 inches

B) 24 inches

C) Width of door plus 6 inches on latch side

D) Width of door served

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27. What is the minimum required bearing for rafters or ceiling joists on wood or metal?

A) 1 inch

B) 3 inches

C) 1½ inches

D) 2 inches

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28. To qualify for the Compact Hot Water Distribution System Option credit (R408.2.3.1), the pipe must store not more than what maximum volume of water between the nearest source of heated water and the termination of the fixture supply pipe?

A) 16 ounces (0.47 L)

B) 32 ounces (0.95 L)

C) 8 ounces (0.24 L)

D) 24 ounces (0.71 L)

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29. What is the minimum distance required between foundation anchor bolts?

A) 3 feet

B) 6 feet

C) 4 feet

D) 5 feet

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30. Which types of copper or copper-alloy tubing are permitted for building sewer pipe?

A) All types

B) Type M or DWV

C) Type K or L

D) Type K, L, M, or DWV

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31. Electric duct heaters must comply with which listing standard?

A) UL 484

B) UL 1996

C) UL 1995

D) UL 1042

32 / 60

32. For a plain masonry foundation wall with 6 feet of unbalanced backfill, 7 feet of unsupported wall height, and SC soil, what is the minimum required wall thickness?

A) 8 inches

B) 6 inches solid or 8 inches

C) 10 inches

D) 12 inches

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33. What is the minimum depth of a pier foundation for a detached deck?

A) 30 inches

B) 12 inches

C) 18 inches

D) 24 inches

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34. What is required for rooftop-mounted photovoltaic panel systems in terms of fire classification?

A) They must be inspected annually for fire compliance

B) They must be tested and labeled in accordance with UL 2703

C) Fire classification is optional unless the system exceeds 10 kW

D) Only Class A panels may be used on all residential structures

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35. What is the minimum height of a guardrail required for stairways more than 30 inches above grade?

A) 30 inches

B) 36 inches

C) 34 inches

D) 42 inches

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36. What is the maximum riser height allowed for residential stairways?

A) 8 inches

B) 7 ¾ inches

C) 9 inches

D) 7 inches

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37. For air-permeable insulation in vented attics, where must the baffle be installed relative to the attic insulation?

A) Over the top of the attic insulation

B) Only adjacent to ridge vents

C) At least 6 inches from the top of the insulation

D) Below the insulation line

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38. In relation to the tank, where must a pressure relief valve be installed?

A) In the water service piping

B) In the lowest part of the tank

C) Directly into a tank tapping or in a water line close to the tank

D) Directly into a drain connection

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39. Sauna heaters must comply with which UL standard?

A) UL 923

B) UL 858

C) UL 875

D) UL 737

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40. Which type of trap installed on the overall drainage system is prohibited?

A) Bell traps

B) Building traps

C) Drum traps

D) "S" traps

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41. What is the maximum allowable span for wood structural panels with a span rating of 24/16, when used as subfloor sheathing?

A) 28 inches

B) 20 inches

C) 16 inches

D) 24 inches

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42. When metallic plugs or plates are used with nonmetallic enclosures to close unused openings, how far must they be recessed from the outer surface of the enclosure?

A) At least 1/2 inch (12.7 mm)

B) At least 1/4 inch (6.4 mm)

C) At least 3/8 inch (9.5 mm)

D) At least 1/8 inch (3.2 mm)

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43. What is the minimum required width of the passageway to access an appliance installed in a room or enclosed space?

A) 30 inches

B) 24 inches

C) 18 inches

D) 36 inches

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44. What is the maximum allowable span for a 2×8, #1 grade Douglas fir-larch rafter spaced 12 inches apart, with a dead load of 10 psf, ceiling not attached, and a roof live load of 50 psf?

A) 18'-5"

B) 16'-0"

C) 15'-6"

D) 15'-3"

45 / 60

45. Boxes enclosing devices or utilization equipment supplied by 14 AWG or smaller conductors must have a minimum internal depth of:

A) 15/16 inch (23.8 mm)

B) 1 3/16 inches (30.2 mm)

C) 13/16 inch (20.6 mm)

D) 2 1/16 inches (52.4 mm)

46 / 60

46. How often must horizontal ties for vertical chimney reinforcement be placed?

A) Every 24 inches

B) Every 36 inches

C) Every 18 inches

D) Every 12 inches

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47. Loose earth used for backfilling shall be carefully placed in the trench in layers of what maximum thickness and tamped in place?

A) 6-inch (152 mm)

B) 12-inch (305 mm)

C) 4-inch (102 mm)

D) 8-inch (203 mm)

48 / 60

48. What is the official title of the IRC as stated in the code?

A) The International Residential Code for One- and Two-Family Dwellings

B) The International Code Council Handbook

C) The International Safety Code

D) The International Building Code

49 / 60

49. Which of the following materials is permitted for constructing return air ducts or plenums if the air temperature does not exceed 125°F and the surfaces are not subject to condensation?

A) Fibrous glass

B) Gypsum products

C) Aluminum foil-backed board

D) Galvanized steel

50 / 60

50. Which of the following is a condition that must be met to use Schedule 40 PVC as exhaust material for a domestic kitchen downdraft system?

A) The PVC duct must be bonded to metal

B) The underfloor trench must be backfilled with sand or gravel

C) PVC duct must be wrapped in insulation

D) PVC duct must terminate through the roof

51 / 60

51. For loads consisting of not more than two two-wire branch circuits in other than dwelling units, the service conductors shall have an ampacity of not less than how many amperes?

A) 100

B) 30

C) 60

D) 15

52 / 60

52. What is the minimum specified compressive strength of concrete required for foundation walls in Seismic Design Categories D0, D1, and D2?

A) 2,500 psi (17.2 MPa) at 28 days

B) 3,000 psi (20.5 MPa) at 28 days

C) 4,000 psi (27.6 MPa) at 28 days

D) 3,500 psi (24.1 MPa) at 28 days

53 / 60

53. Where must the heat-sensing element for a sauna thermostat be located if it is not integral to the unit?

A) Inside the timer housing enclosure

B) Behind the sauna heater guard

C) Within 6 inches of the ceiling

D) Adjacent to the combustion air inlet

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54. What is the minimum required egress width between two handrails for a stairway?

A) 27 inches

B) 34 inches

C) 36 inches

D) 32 inches

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55. Can a multiwire branch circuit be considered multiple circuits?

A) Only when connected to separate overcurrent devices

B) Only if serving more than one appliance

C) No

D) Yes

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56. According to the IRC, what design loads must decks be designed for?

A) The greater of the live load in Section R301.5 or the ground snow load from Table R301.2

B) A minimum live load of 30 psf

C) The local wind load as determined by ASCE 7

D) The dead load of the decking and joists only

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57. The mechanical interlock is intended to:

A) Ensure the appliance thermostat maintains setpoint

B) Prevent the air handler from cycling too frequently

C) Balance the combustion air with return air pressure

D) Shut down main burner operation if the air supply system is not operating

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58. Which ASTM standard applies to polyisocyanurate insulation board used above roof decks?

A) ASTM C552

B) ASTM C1289

C) ASTM C208

D) ASTM C1177

59 / 60

59. What is the minimum setback for a detached garage from a property line when the walls are not fire rated and sprinklers are not provided?

A) 10 feet

B) 15 feet

C) 3 feet

D) 5 feet

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60. What is the minimum size of wood blocking required at the perimeter of a horizontal gypsum board diaphragm ceiling?

A) 1 inch by 4 inches

B) 2 inch by 8 inches

C) 2 inch by 4 inches

D) 2 inch by 6 inches

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2024 Residential Plans Examiner – Practice Quiz (Untimed)

“This untimed practice quiz simulates the ICC exam format, giving you full exposure to real-style questions while allowing unlimited time to navigate, learn, and build confidence without time pressure.”