New Jersey Residential Building Inspector
Examination Questions and Correct Answers
(Verified Answers) Plus Rationale
Question 1
Where reinforcement is provided in concrete slabs on ground floors, the
reinforcement shall be supported to remain within what section of the slab during
concrete placement?
Correct Answer
center to upper one third of the slab
Question 1: According to the New Jersey Uniform Construction Code (UCC)
and the adopted International Residential Code (IRC) with state amendments,
what is the minimum required width for a means of egress door in a
residential dwelling, and what additional requirement applies to the clear
opening?
A. 28 inches minimum width with no specific clear opening requirement
B. 32 inches minimum width providing a clear opening of not less than 32 inches
when measured between the face of the door and the stop with the door open 90
degrees
C. 36 inches minimum width with a clear opening of 34 inches
D. 30 inches minimum width with no hardware restrictions
CORRECT ANSWER: B. 32 inches minimum width providing a clear opening of
not less than 32 inches when measured between the face of the door and the
stop with the door open 90 degrees
Rationale: The IRC (as adopted and amended in New Jersey) requires egress doors
to provide a minimum clear width of 32 inches. This measurement is taken with the
door open 90 degrees between the face of the door and the stop. Proper egress
sizing is critical for life safety during emergencies.
Question 2: When inspecting a residential foundation in New Jersey, what is
the minimum required thickness for a concrete footing supporting a
conventional wood-frame exterior wall on soil with an allowable bearing
pressure of 1,500 psf, assuming no special engineering?
A. 6 inches
B. 8 inches
C. 12 inches
D. 16 inches
Page 1 of 105
,CORRECT ANSWER: B. 8 inches
Rationale: Under the IRC foundation requirements adopted in New Jersey, the
minimum thickness for continuous concrete footings supporting light-frame
construction is generally 8 inches when soil bearing capacity meets standard values.
Inspectors must also verify projection beyond the wall, reinforcement where
required, and proper depth below frost line.
Question 3: During a rough framing inspection of a two-story residential
dwelling in New Jersey, the inspector observes that the floor joists are 2×10
Southern Pine spaced 16 inches on center spanning 14 feet. What is the most
important additional factor the inspector must verify regarding the joists?
A. That the joists are only pressure-treated
B. That the species, grade, span, spacing, and load conditions comply with the IRC
span tables or approved design values, and that proper bearing and bracing are
provided
C. That the joists are painted before installation
D. That the joists are installed with crowns down
CORRECT ANSWER: B. That the species, grade, span, spacing, and load
conditions comply with the IRC span tables or approved design values, and
that proper bearing and bracing are provided
Rationale: Residential building inspectors must confirm that framing members meet
the prescriptive span tables in the IRC (or engineered design) for the specific
species, grade, spacing, and design loads. Inadequate span capacity or missing
bridging/bracing can lead to structural failure.
Question 4: According to New Jersey residential code requirements for guards
(guardrails), what is the maximum allowable opening size in a guard
protecting a walking surface located more than 30 inches above the floor or
grade below?
A. 6 inches
B. A sphere 4 inches in diameter shall not pass through any opening
C. 5 inches
D. No limitation if the guard is 36 inches high
CORRECT ANSWER: B. A sphere 4 inches in diameter shall not pass through
any opening
Rationale: The IRC requires that guards be constructed so that a 4-inch-diameter
sphere cannot pass through any opening. This prevents small children from falling
through. Height requirements (typically 36 inches minimum for residential) and
intermediate rail strength must also be verified.
Question 5: When performing an inspection of a residential electrical service in
Page 2 of 105
,New Jersey, what is the minimum service disconnecting means rating required
for a single-family dwelling?
A. 60 amperes
B. 100 amperes
C. 150 amperes
D. 200 amperes
CORRECT ANSWER: B. 100 amperes
Rationale: The National Electrical Code (NEC), as adopted under the New Jersey
UCC, requires a minimum 100-ampere service for a one-family dwelling. Inspectors
must also verify proper grounding, bonding, conductor sizing, and that the service
equipment is suitable for the calculated load.
Question 6: In New Jersey residential construction, what is the minimum
required R-value for ceiling insulation in Climate Zone 5 (which includes most
of the state) under the energy conservation provisions of the IRC/IECC as
adopted?
A. R-30
B. R-38
C. R-49
D. R-60
CORRECT ANSWER: C. R-49
Rationale: New Jersey has adopted energy code requirements based on the
IECC/IRC that mandate higher insulation levels. For Climate Zone 5, ceiling (attic)
insulation is typically required to meet R-49. Inspectors verify installed thickness,
coverage, and proper installation without compression or gaps.
Question 7: During a plumbing rough-in inspection, the inspector finds that a
water closet is connected to a 3-inch horizontal drain line. What additional
requirement must be verified regarding the slope of that drain?
A. Minimum slope of 1/8 inch per foot
B. Minimum slope of 1/4 inch per foot
C. Minimum slope of 1/2 inch per foot
D. No slope is required if the pipe is PVC
CORRECT ANSWER: B. Minimum slope of 1/4 inch per foot
Rationale: The IRC plumbing provisions require horizontal drainage piping 3 inches
or less in diameter to be installed at a minimum slope of 1/4 inch per foot to ensure
proper flow and prevent blockages. Larger pipes may use 1/8 inch per foot under
certain conditions.
Question 8: What is the maximum riser height and minimum tread depth
Page 3 of 105
, allowed for residential stairways in New Jersey under the IRC as adopted?
A. 7¾ inches maximum riser and 10 inches minimum tread
B. 8¼ inches maximum riser and 9 inches minimum tread
C. 7 inches maximum riser and 11 inches minimum tread
D. 8 inches maximum riser and 9 inches minimum tread
CORRECT ANSWER: A. 7¾ inches maximum riser and 10 inches minimum
tread
Rationale: The IRC sets a maximum riser height of 7¾ inches and a minimum tread
depth of 10 inches for residential stairs. Consistency of riser and tread dimensions
within a flight is also required (maximum variation of ⅜ inch). Inspectors must
measure carefully.
Question 9: When inspecting a residential deck attached to a dwelling in New
Jersey, what is the primary concern regarding the ledger board connection?
A. That the ledger is painted to match the house
B. That the ledger is properly flashed and attached with approved fasteners (such as
lag screws or through-bolts) in accordance with IRC deck attachment requirements,
and that lateral load connections are provided where required
C. That the ledger is only toe-nailed
D. That the ledger is made of plastic composite material only
CORRECT ANSWER: B. That the ledger is properly flashed and attached with
approved fasteners (such as lag screws or through-bolts) in accordance with
IRC deck attachment requirements, and that lateral load connections are
provided where required
Rationale: Improper ledger attachment is a leading cause of deck collapses. New
Jersey inspectors must verify correct fastener type, size, spacing, flashing to prevent
water intrusion, and lateral restraint where mandated by code.
Question 10: According to New Jersey residential code requirements, where is
a smoke alarm required to be installed in a new single-family dwelling?
A. Only in the hallway outside bedrooms
B. In each sleeping room, outside each separate sleeping area in the immediate
vicinity of the bedrooms, and on each additional story of the dwelling, including
basements
C. Only on the main floor
D. Only near the kitchen
CORRECT ANSWER: B. In each sleeping room, outside each separate sleeping
area in the immediate vicinity of the bedrooms, and on each additional story
of the dwelling, including basements
Page 4 of 105
Examination Questions and Correct Answers
(Verified Answers) Plus Rationale
Question 1
Where reinforcement is provided in concrete slabs on ground floors, the
reinforcement shall be supported to remain within what section of the slab during
concrete placement?
Correct Answer
center to upper one third of the slab
Question 1: According to the New Jersey Uniform Construction Code (UCC)
and the adopted International Residential Code (IRC) with state amendments,
what is the minimum required width for a means of egress door in a
residential dwelling, and what additional requirement applies to the clear
opening?
A. 28 inches minimum width with no specific clear opening requirement
B. 32 inches minimum width providing a clear opening of not less than 32 inches
when measured between the face of the door and the stop with the door open 90
degrees
C. 36 inches minimum width with a clear opening of 34 inches
D. 30 inches minimum width with no hardware restrictions
CORRECT ANSWER: B. 32 inches minimum width providing a clear opening of
not less than 32 inches when measured between the face of the door and the
stop with the door open 90 degrees
Rationale: The IRC (as adopted and amended in New Jersey) requires egress doors
to provide a minimum clear width of 32 inches. This measurement is taken with the
door open 90 degrees between the face of the door and the stop. Proper egress
sizing is critical for life safety during emergencies.
Question 2: When inspecting a residential foundation in New Jersey, what is
the minimum required thickness for a concrete footing supporting a
conventional wood-frame exterior wall on soil with an allowable bearing
pressure of 1,500 psf, assuming no special engineering?
A. 6 inches
B. 8 inches
C. 12 inches
D. 16 inches
Page 1 of 105
,CORRECT ANSWER: B. 8 inches
Rationale: Under the IRC foundation requirements adopted in New Jersey, the
minimum thickness for continuous concrete footings supporting light-frame
construction is generally 8 inches when soil bearing capacity meets standard values.
Inspectors must also verify projection beyond the wall, reinforcement where
required, and proper depth below frost line.
Question 3: During a rough framing inspection of a two-story residential
dwelling in New Jersey, the inspector observes that the floor joists are 2×10
Southern Pine spaced 16 inches on center spanning 14 feet. What is the most
important additional factor the inspector must verify regarding the joists?
A. That the joists are only pressure-treated
B. That the species, grade, span, spacing, and load conditions comply with the IRC
span tables or approved design values, and that proper bearing and bracing are
provided
C. That the joists are painted before installation
D. That the joists are installed with crowns down
CORRECT ANSWER: B. That the species, grade, span, spacing, and load
conditions comply with the IRC span tables or approved design values, and
that proper bearing and bracing are provided
Rationale: Residential building inspectors must confirm that framing members meet
the prescriptive span tables in the IRC (or engineered design) for the specific
species, grade, spacing, and design loads. Inadequate span capacity or missing
bridging/bracing can lead to structural failure.
Question 4: According to New Jersey residential code requirements for guards
(guardrails), what is the maximum allowable opening size in a guard
protecting a walking surface located more than 30 inches above the floor or
grade below?
A. 6 inches
B. A sphere 4 inches in diameter shall not pass through any opening
C. 5 inches
D. No limitation if the guard is 36 inches high
CORRECT ANSWER: B. A sphere 4 inches in diameter shall not pass through
any opening
Rationale: The IRC requires that guards be constructed so that a 4-inch-diameter
sphere cannot pass through any opening. This prevents small children from falling
through. Height requirements (typically 36 inches minimum for residential) and
intermediate rail strength must also be verified.
Question 5: When performing an inspection of a residential electrical service in
Page 2 of 105
,New Jersey, what is the minimum service disconnecting means rating required
for a single-family dwelling?
A. 60 amperes
B. 100 amperes
C. 150 amperes
D. 200 amperes
CORRECT ANSWER: B. 100 amperes
Rationale: The National Electrical Code (NEC), as adopted under the New Jersey
UCC, requires a minimum 100-ampere service for a one-family dwelling. Inspectors
must also verify proper grounding, bonding, conductor sizing, and that the service
equipment is suitable for the calculated load.
Question 6: In New Jersey residential construction, what is the minimum
required R-value for ceiling insulation in Climate Zone 5 (which includes most
of the state) under the energy conservation provisions of the IRC/IECC as
adopted?
A. R-30
B. R-38
C. R-49
D. R-60
CORRECT ANSWER: C. R-49
Rationale: New Jersey has adopted energy code requirements based on the
IECC/IRC that mandate higher insulation levels. For Climate Zone 5, ceiling (attic)
insulation is typically required to meet R-49. Inspectors verify installed thickness,
coverage, and proper installation without compression or gaps.
Question 7: During a plumbing rough-in inspection, the inspector finds that a
water closet is connected to a 3-inch horizontal drain line. What additional
requirement must be verified regarding the slope of that drain?
A. Minimum slope of 1/8 inch per foot
B. Minimum slope of 1/4 inch per foot
C. Minimum slope of 1/2 inch per foot
D. No slope is required if the pipe is PVC
CORRECT ANSWER: B. Minimum slope of 1/4 inch per foot
Rationale: The IRC plumbing provisions require horizontal drainage piping 3 inches
or less in diameter to be installed at a minimum slope of 1/4 inch per foot to ensure
proper flow and prevent blockages. Larger pipes may use 1/8 inch per foot under
certain conditions.
Question 8: What is the maximum riser height and minimum tread depth
Page 3 of 105
, allowed for residential stairways in New Jersey under the IRC as adopted?
A. 7¾ inches maximum riser and 10 inches minimum tread
B. 8¼ inches maximum riser and 9 inches minimum tread
C. 7 inches maximum riser and 11 inches minimum tread
D. 8 inches maximum riser and 9 inches minimum tread
CORRECT ANSWER: A. 7¾ inches maximum riser and 10 inches minimum
tread
Rationale: The IRC sets a maximum riser height of 7¾ inches and a minimum tread
depth of 10 inches for residential stairs. Consistency of riser and tread dimensions
within a flight is also required (maximum variation of ⅜ inch). Inspectors must
measure carefully.
Question 9: When inspecting a residential deck attached to a dwelling in New
Jersey, what is the primary concern regarding the ledger board connection?
A. That the ledger is painted to match the house
B. That the ledger is properly flashed and attached with approved fasteners (such as
lag screws or through-bolts) in accordance with IRC deck attachment requirements,
and that lateral load connections are provided where required
C. That the ledger is only toe-nailed
D. That the ledger is made of plastic composite material only
CORRECT ANSWER: B. That the ledger is properly flashed and attached with
approved fasteners (such as lag screws or through-bolts) in accordance with
IRC deck attachment requirements, and that lateral load connections are
provided where required
Rationale: Improper ledger attachment is a leading cause of deck collapses. New
Jersey inspectors must verify correct fastener type, size, spacing, flashing to prevent
water intrusion, and lateral restraint where mandated by code.
Question 10: According to New Jersey residential code requirements, where is
a smoke alarm required to be installed in a new single-family dwelling?
A. Only in the hallway outside bedrooms
B. In each sleeping room, outside each separate sleeping area in the immediate
vicinity of the bedrooms, and on each additional story of the dwelling, including
basements
C. Only on the main floor
D. Only near the kitchen
CORRECT ANSWER: B. In each sleeping room, outside each separate sleeping
area in the immediate vicinity of the bedrooms, and on each additional story
of the dwelling, including basements
Page 4 of 105
