CMI CMI Advanced Defect Analysis & Documentation 2 — Questions and Answers
Question 1: A CMI identifies reversed polarity at multiple outlets throughout a home. Which component is the most likely cause?
- Faulty breakers in the panel
- Hot and neutral wires were swapped at the outlet, a junction box, or at the panel (Correct answer)
- The utility service entrance is wired incorrectly
- Ground fault circuit interrupters were installed backwards
Correct answer: Hot and neutral wires were swapped at the outlet, a junction box, or at the panel
Reversed polarity is almost always a wiring error at the connection point — outlet, junction box, or panel — where hot and neutral conductors were inadvertently transposed.
Question 2: What does a high static pressure drop across an HVAC air filter most likely indicate?
- The system is operating efficiently
- The filter is clogged or too restrictive, reducing airflow and stressing the blower (Correct answer)
- The ductwork is oversized
- The thermostat is malfunctioning
Correct answer: The filter is clogged or too restrictive, reducing airflow and stressing the blower
Excessive static pressure drop across a filter signals restriction from clogging or an overly dense filter media, which reduces airflow and can cause blower motor stress and coil icing.
Question 3: During a roof inspection, a CMI observes granule loss concentrated at the north-facing slope. What is the most likely explanation?
- Manufacturing defect across the entire roof
- Prolonged moisture retention on the shaded slope accelerating granule loss and aging (Correct answer)
- Hail damage limited to the north slope
- Normal UV degradation pattern
Correct answer: Prolonged moisture retention on the shaded slope accelerating granule loss and aging
North-facing slopes receive less sunlight and dry more slowly, promoting algae and moss growth that actively loosen and displace surface granules over time.
Question 4: A CMI notes that a gas water heater flue connector has a downward pitch toward the appliance. Why is this a critical safety defect?
- It causes excessive condensation in the tank
- A downward pitch traps combustion gases including carbon monoxide, preventing proper venting to the exterior (Correct answer)
- It violates only aesthetic standards
- It only affects venting efficiency, not safety
Correct answer: A downward pitch traps combustion gases including carbon monoxide, preventing proper venting to the exterior
Flue connectors must pitch upward continuously toward the chimney so buoyancy drives combustion gases out; a dip allows CO and other products to back-draft into the living space.
Question 5: What does the term 'negative drainage' mean in a home inspection context?
- Drainage pipes that run underground
- Grading that slopes toward the foundation, directing surface water against the structure (Correct answer)
- A sump pump that drains outward
- Roof drainage that bypasses gutters
Correct answer: Grading that slopes toward the foundation, directing surface water against the structure
Negative drainage describes a grade that falls toward rather than away from the foundation, channeling rainwater and snowmelt against the structure and increasing basement water intrusion risk.
Question 6: A CMI observes cupping of hardwood floor boards. What is the primary cause of this condition?
- Excessive sanding during installation
- Moisture imbalance where the bottom of the boards has higher moisture content than the top (Correct answer)
- Normal aging of solid hardwood
- Subfloor fastener spacing that is too wide
Correct answer: Moisture imbalance where the bottom of the boards has higher moisture content than the top
Cupping occurs when the underside of a hardwood board absorbs more moisture than the top surface, causing the edges to rise as the bottom swells more than the face.
CMI CMI Advanced Defect Analysis & Documentation 2
A CMI identifies reversed polarity at multiple outlets throughout a home.
Which component is the most likely cause?