CMI CMI Advanced Diagnostic Methods 2 — Questions and Answers
Question 1: What is the purpose of performing a static pressure test on a water supply system during a CMI inspection?
- To determine the water's mineral content
- To verify supply pressure is within the acceptable range of 40–80 psi and check for pressure fluctuations (Correct answer)
- To test water heater output temperature
- To measure flow rate at individual fixtures
Correct answer: To verify supply pressure is within the acceptable range of 40–80 psi and check for pressure fluctuations
Static pressure testing confirms the supply pressure falls within the safe operational range; pressure above 80 psi can damage fixtures and appliances, while low pressure indicates supply problems.
Question 2: A CMI uses a combustible gas detector near a gas meter and detects a reading. What is the correct immediate action?
- Note it in the report and continue the inspection
- Leave the property, advise all occupants to evacuate, and contact the gas utility immediately (Correct answer)
- Open windows to ventilate and retest in 10 minutes
- Locate the shut-off valve and close it before continuing
Correct answer: Leave the property, advise all occupants to evacuate, and contact the gas utility immediately
A confirmed gas leak is an immediate life-safety emergency requiring evacuation and utility notification before any other action.
Question 3: When inspecting electrical panels, what does a CMI look for to identify a double-tapped breaker?
- Two breakers connected in series
- Multiple conductors (wires) connected to a single breaker terminal not rated for that configuration (Correct answer)
- A breaker with two different amperage ratings
- A tandem breaker installed in a non-tandem slot
Correct answer: Multiple conductors (wires) connected to a single breaker terminal not rated for that configuration
A double-tap occurs when two conductors share one breaker terminal, creating a potential loose connection, overheating, and overcurrent protection failure unless the breaker is rated for multiple conductors.
Question 4: Which diagnostic technique does a CMI use to differentiate active efflorescence from old, inactive efflorescence on a masonry wall?
- Check the color—white indicates active, gray indicates inactive
- Test moisture levels with a meter and observe if new deposits are forming at current moisture intrusion points (Correct answer)
- Active efflorescence always appears wet to the touch
- Old efflorescence always crumbles when touched
Correct answer: Test moisture levels with a meter and observe if new deposits are forming at current moisture intrusion points
Elevated moisture readings near efflorescence deposits and evidence of continuing deposit growth indicate active water migration, while dry readings with stable deposits suggest the condition may be historical.
Question 5: A CMI inspecting a crawl space observes wood with a cubical cracking pattern throughout the grain. This describes which type of wood decay?
- White rot
- Brown rot (dry rot) (Correct answer)
- Surface mold colonization
- Insect boring damage
Correct answer: Brown rot (dry rot)
Brown rot (often called dry rot) breaks down cellulose in wood, leaving characteristic cubical or block-like cracking patterns across the grain as the wood shrinks and collapses.
Question 6: When a CMI is inspecting AFCI (Arc Fault Circuit Interrupter) breaker protection, which circuit locations require AFCI protection under current NEC standards for new US construction?
- Outdoor circuits and garage circuits only
- Virtually all 15A and 20A, 120V circuits in dwelling unit living spaces including bedrooms, living rooms, kitchens, and hallways (Correct answer)
- Only circuits within 6 feet of water sources
- Only circuits in rooms with carpet flooring
Correct answer: Virtually all 15A and 20A, 120V circuits in dwelling unit living spaces including bedrooms, living rooms, kitchens, and hallways
The NEC has progressively expanded AFCI requirements to cover nearly all 15A and 20A, 120V branch circuits in dwelling units to protect against arc-fault ignition fires.
CMI CMI Advanced Diagnostic Methods 2
What is the purpose of performing a static pressure test on a water supply system during a CMI inspection?