IICRC WRT PROFESSIONAL
CERTIFICATION EXAMINATION
2026/2027 QUESTIONS AND ANSWERS
1. When calculating the initial dehumidification capacity for a Class 2 water loss in a 15,000
cubic foot commercial space using an LGR dehumidifier, what is the divisor according to the
S500 standard?
A. 60
B. 50
C. 40
D. 100
Answer: C
Conceptual Explanation: According to the IICRC S500, for an LGR dehumidifier in a Class
2 water loss, the initial calculation requires dividing the cubic footage by 40 to determine
the pints of removal required.
,2. Which of the following describes the ‘Dry Goal’ in professional water restoration?
A. The moisture content of an unaffected material of the same type in the same
environment.
B. The point at which the vapor pressure of the air equals the vapor pressure of the
material.
C. The moisture reading of a material after 24 hours of drying.
D. The predetermined moisture level that must be achieved to conclude the drying process.
Answer: D
Conceptual Explanation: The Dry Goal is the specific target moisture level determined by
the restoration professional, often based on the Dry Standard (unaffected material), which
signifies the completion of the drying process.
3. In a Category 3 water intrusion, which of the following is the most appropriate action
regarding structural carpet padding?
A. Clean and sanitize in place.
B. Dry with high-velocity air movers and apply biocides.
C. Remove and replace after cleaning the subfloor.
D. Remove and dispose of as hazardous waste.
Answer: C
, Conceptual Explanation: Category 3 water contains significant pathogens. Highly porous
materials like carpet padding cannot be adequately cleaned or decontaminated and must
be removed and replaced.
4. What is the primary physical principle used by a desiccant dehumidifier to remove
moisture from the air?
A. Adsorption of water molecules onto a silica gel wheel.
B. Cooling the air below its dew point.
C. Compression of air to force water out of suspension.
D. Increasing the air temperature to lower the relative humidity.
Answer: A
Conceptual Explanation: Desiccant dehumidifiers use chemical attraction (adsorption) to
pull moisture from the air onto a surface like a silica gel wheel, which works even at very
low temperatures and humidities.
5. If the temperature of a room increases while the absolute humidity (GPP) remains
constant, what happens to the Relative Humidity (RH)?
A. RH increases.
B. RH stays the same.
C. RH decreases.
D. RH becomes equal to the dew point.
CERTIFICATION EXAMINATION
2026/2027 QUESTIONS AND ANSWERS
1. When calculating the initial dehumidification capacity for a Class 2 water loss in a 15,000
cubic foot commercial space using an LGR dehumidifier, what is the divisor according to the
S500 standard?
A. 60
B. 50
C. 40
D. 100
Answer: C
Conceptual Explanation: According to the IICRC S500, for an LGR dehumidifier in a Class
2 water loss, the initial calculation requires dividing the cubic footage by 40 to determine
the pints of removal required.
,2. Which of the following describes the ‘Dry Goal’ in professional water restoration?
A. The moisture content of an unaffected material of the same type in the same
environment.
B. The point at which the vapor pressure of the air equals the vapor pressure of the
material.
C. The moisture reading of a material after 24 hours of drying.
D. The predetermined moisture level that must be achieved to conclude the drying process.
Answer: D
Conceptual Explanation: The Dry Goal is the specific target moisture level determined by
the restoration professional, often based on the Dry Standard (unaffected material), which
signifies the completion of the drying process.
3. In a Category 3 water intrusion, which of the following is the most appropriate action
regarding structural carpet padding?
A. Clean and sanitize in place.
B. Dry with high-velocity air movers and apply biocides.
C. Remove and replace after cleaning the subfloor.
D. Remove and dispose of as hazardous waste.
Answer: C
, Conceptual Explanation: Category 3 water contains significant pathogens. Highly porous
materials like carpet padding cannot be adequately cleaned or decontaminated and must
be removed and replaced.
4. What is the primary physical principle used by a desiccant dehumidifier to remove
moisture from the air?
A. Adsorption of water molecules onto a silica gel wheel.
B. Cooling the air below its dew point.
C. Compression of air to force water out of suspension.
D. Increasing the air temperature to lower the relative humidity.
Answer: A
Conceptual Explanation: Desiccant dehumidifiers use chemical attraction (adsorption) to
pull moisture from the air onto a surface like a silica gel wheel, which works even at very
low temperatures and humidities.
5. If the temperature of a room increases while the absolute humidity (GPP) remains
constant, what happens to the Relative Humidity (RH)?
A. RH increases.
B. RH stays the same.
C. RH decreases.
D. RH becomes equal to the dew point.
