National Home inspector exam 494 UPDATED ACTUAL Questions and
CORRECT Answers
Question: At what level would water pressure within a single-family dwelling begin to be considered
excessive and require correction
Correct Answer: 80 PSI
Question: buckling in horizontal vinyl siding is generally caused by
Correct Answer: improper fastening
Question: A newer home with electric heat is being inspected. It has a below grade finished basement
containing a bedroom. The inspector should look for a smoke alarm and
Correct Answer: an escape and rescue opening
Question: A swimming pool fence must prevent passage of a sphere that is larger than
Correct Answer: 4 inches
Question: If water infiltration is suspected behind a finished surface, what tool would be the best choice to
verify dampness?
Correct Answer: non-contact moisture meter
Question: Gas-fired furnace heat exchangers most often fail from
Correct Answer: rust and metal fatigue
Question: relative humidity (RH) is expressed as
Correct Answer: percentage
Question: Connections of dissimilar metal in a plumbing system, such as galvanized steel pipe and copper
pipe, will usually cause
Correct Answer: electrolysis
Question: A ground fault circuit interrupter (GFCI) is a safety device that
Correct Answer: disconnects the power when sensing current leakage to ground
Question: An electrical system with a fuse on the neutral conductor and on the energized (hot) conductors
Correct Answer: is hazardous and should be corrected
Question: To operate a central air conditioner, an electric clothes dryer, and and electric range, the
ampacity of the service to the house should be AT LEAST
Correct Answer: 100 amps at 240 volts
Question: A floor joist in a crawl space has been cut where the toilet drain passes through the floor. the
joists are 2x6 spaced at 16" on center. The inspector should recommend that
Correct Answer: a contractor be contacted to determine what is needed and make repairs
Question: Most problems with concrete are caused at the time of installation. What single factor causes
MOST problems
Correct Answer: Too much water is added to the mix
CORRECT Answers
Question: At what level would water pressure within a single-family dwelling begin to be considered
excessive and require correction
Correct Answer: 80 PSI
Question: buckling in horizontal vinyl siding is generally caused by
Correct Answer: improper fastening
Question: A newer home with electric heat is being inspected. It has a below grade finished basement
containing a bedroom. The inspector should look for a smoke alarm and
Correct Answer: an escape and rescue opening
Question: A swimming pool fence must prevent passage of a sphere that is larger than
Correct Answer: 4 inches
Question: If water infiltration is suspected behind a finished surface, what tool would be the best choice to
verify dampness?
Correct Answer: non-contact moisture meter
Question: Gas-fired furnace heat exchangers most often fail from
Correct Answer: rust and metal fatigue
Question: relative humidity (RH) is expressed as
Correct Answer: percentage
Question: Connections of dissimilar metal in a plumbing system, such as galvanized steel pipe and copper
pipe, will usually cause
Correct Answer: electrolysis
Question: A ground fault circuit interrupter (GFCI) is a safety device that
Correct Answer: disconnects the power when sensing current leakage to ground
Question: An electrical system with a fuse on the neutral conductor and on the energized (hot) conductors
Correct Answer: is hazardous and should be corrected
Question: To operate a central air conditioner, an electric clothes dryer, and and electric range, the
ampacity of the service to the house should be AT LEAST
Correct Answer: 100 amps at 240 volts
Question: A floor joist in a crawl space has been cut where the toilet drain passes through the floor. the
joists are 2x6 spaced at 16" on center. The inspector should recommend that
Correct Answer: a contractor be contacted to determine what is needed and make repairs
Question: Most problems with concrete are caused at the time of installation. What single factor causes
MOST problems
Correct Answer: Too much water is added to the mix
