ICC Residential Combination Inspector
(multi-trade) Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
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1. A one- and two-family dwelling fire-resistance separation between
dwelling units must be at least:
A. 30 minutes
B. 1 hour
C. 2 hours
D. 3 hours
Rationale: A minimum 1-hour fire-resistance rating is required
between dwelling units in many residential code applications to slow
fire spread and allow safe evacuation.
2. Minimum ceiling height in habitable rooms is generally:
A. 6 feet 8 inches
B. 7 feet 0 inches
, C. 7 feet 6 inches
D. 8 feet 0 inches
Rationale: Residential codes typically require a minimum 7-foot
ceiling height in habitable spaces for safety and usability.
3. The minimum slope for a 2% drain is equivalent to:
A. 1/16 inch per foot
B. 1/4 inch per foot
C. 1/8 inch per foot
D. 1 inch per foot
Rationale: A 2% slope equals 1/4 inch per foot, commonly used for
drainage piping.
4. Frost depth requirements are intended primarily to prevent:
A. Pipe corrosion
B. Thermal expansion
C. Freezing of water in soil and footings
D. Soil settlement
Rationale: Footings must extend below frost depth to prevent
heaving due to freezing water expansion.
5. The minimum width of a residential exit door is generally:
A. 24 inches
B. 28 inches
C. 32 inches
D. 36 inches
, Rationale: Residential codes typically require at least 32-inch clear
width for egress doors.
6. Which component is required for a vent system to function properly?
A. Trap primer
B. Backflow preventer
C. Air admittance or open vent path
D. Cleanout only
Rationale: Vent systems require air circulation to prevent trap
siphonage and maintain pressure balance.
7. Concrete minimum compressive strength for residential slabs is
commonly:
A. 1500 psi
B. 2000 psi
C. 2500–3000 psi
D. 5000 psi
Rationale: Residential slabs typically use 2500–3000 psi concrete
depending on exposure and design.
8. Electrical grounding system is intended to:
A. Increase voltage
B. Reduce resistance only
C. Provide a safe fault current path to earth
D. Store electricity
(multi-trade) Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
Download Pdf
1. A one- and two-family dwelling fire-resistance separation between
dwelling units must be at least:
A. 30 minutes
B. 1 hour
C. 2 hours
D. 3 hours
Rationale: A minimum 1-hour fire-resistance rating is required
between dwelling units in many residential code applications to slow
fire spread and allow safe evacuation.
2. Minimum ceiling height in habitable rooms is generally:
A. 6 feet 8 inches
B. 7 feet 0 inches
, C. 7 feet 6 inches
D. 8 feet 0 inches
Rationale: Residential codes typically require a minimum 7-foot
ceiling height in habitable spaces for safety and usability.
3. The minimum slope for a 2% drain is equivalent to:
A. 1/16 inch per foot
B. 1/4 inch per foot
C. 1/8 inch per foot
D. 1 inch per foot
Rationale: A 2% slope equals 1/4 inch per foot, commonly used for
drainage piping.
4. Frost depth requirements are intended primarily to prevent:
A. Pipe corrosion
B. Thermal expansion
C. Freezing of water in soil and footings
D. Soil settlement
Rationale: Footings must extend below frost depth to prevent
heaving due to freezing water expansion.
5. The minimum width of a residential exit door is generally:
A. 24 inches
B. 28 inches
C. 32 inches
D. 36 inches
, Rationale: Residential codes typically require at least 32-inch clear
width for egress doors.
6. Which component is required for a vent system to function properly?
A. Trap primer
B. Backflow preventer
C. Air admittance or open vent path
D. Cleanout only
Rationale: Vent systems require air circulation to prevent trap
siphonage and maintain pressure balance.
7. Concrete minimum compressive strength for residential slabs is
commonly:
A. 1500 psi
B. 2000 psi
C. 2500–3000 psi
D. 5000 psi
Rationale: Residential slabs typically use 2500–3000 psi concrete
depending on exposure and design.
8. Electrical grounding system is intended to:
A. Increase voltage
B. Reduce resistance only
C. Provide a safe fault current path to earth
D. Store electricity
