IICRC WRT ADVANCED
CERTIFICATION EXAM 2026
QUESTIONS AND ANSWERS
1. What is the primary driving force behind the movement of moisture from the surface of a
wet material into the air during the drying process?
A. Vapor Pressure Differential
B. Relative Humidity
C. Capillary Action
D. Air Velocity
Answer: A
Conceptual Explanation: Vapor pressure differential is the difference between the vapor
pressure of the water in the material and the vapor pressure of the air. A higher differential
leads to faster evaporation.
2. According to the ANSI/IICRC S500, how is Category 2 water defined?
A. Water that originates from a sanitary source and does not pose substantial risk.
,B. Water that contains significant contamination and has the potential to cause discomfort
or sickness.
C. Water that is grossly contaminated and can contain pathogenic, toxigenic, or other
harmful agents.
D. Water that contains regulated hazardous materials like asbestos or lead.
Answer: B
Conceptual Explanation: Category 2 water (formerly known as grey water) contains
significant contamination, whereas Category 1 is clean and Category 3 is grossly
contaminated.
3. Which psychrometric term describes the weight of water vapor in a pound of dry air?
A. Humidity Ratio (Grains per Pound)
B. Dew Point
C. Relative Humidity
D. Vapor Pressure
Answer: A
Conceptual Explanation: Humidity ratio, measured in Grains Per Pound (GPP), represents
the actual weight of moisture in the air regardless of temperature.
4. What is the ‘dry standard’ in a water restoration project?
A. The moisture content of a similar unaffected material in the same environment.
, B. A moisture reading of zero percent in all materials.
C. The equilibrium moisture content (EMC) as defined by the EPA.
D. A standard 10% moisture content for all wood substrates.
Answer: A
Conceptual Explanation: The dry standard is established by measuring a known dry
(unaffected) material to determine the goal for the affected materials.
5. Which class of water intrusion involves the largest amount of water, where materials have
a high constant rate of evaporation (e.g., ceilings, walls, and floors are all saturated)?
A. Class 1
B. Class 2
C. Class 3
D. Class 4
Answer: C
Conceptual Explanation: Class 3 involves the greatest amount of water and the most
surface area of highly porous materials being affected.
6. At what point does wood reach the Fiber Saturation Point (FSP) on average?
A. 15% MC
B. 30% MC
CERTIFICATION EXAM 2026
QUESTIONS AND ANSWERS
1. What is the primary driving force behind the movement of moisture from the surface of a
wet material into the air during the drying process?
A. Vapor Pressure Differential
B. Relative Humidity
C. Capillary Action
D. Air Velocity
Answer: A
Conceptual Explanation: Vapor pressure differential is the difference between the vapor
pressure of the water in the material and the vapor pressure of the air. A higher differential
leads to faster evaporation.
2. According to the ANSI/IICRC S500, how is Category 2 water defined?
A. Water that originates from a sanitary source and does not pose substantial risk.
,B. Water that contains significant contamination and has the potential to cause discomfort
or sickness.
C. Water that is grossly contaminated and can contain pathogenic, toxigenic, or other
harmful agents.
D. Water that contains regulated hazardous materials like asbestos or lead.
Answer: B
Conceptual Explanation: Category 2 water (formerly known as grey water) contains
significant contamination, whereas Category 1 is clean and Category 3 is grossly
contaminated.
3. Which psychrometric term describes the weight of water vapor in a pound of dry air?
A. Humidity Ratio (Grains per Pound)
B. Dew Point
C. Relative Humidity
D. Vapor Pressure
Answer: A
Conceptual Explanation: Humidity ratio, measured in Grains Per Pound (GPP), represents
the actual weight of moisture in the air regardless of temperature.
4. What is the ‘dry standard’ in a water restoration project?
A. The moisture content of a similar unaffected material in the same environment.
, B. A moisture reading of zero percent in all materials.
C. The equilibrium moisture content (EMC) as defined by the EPA.
D. A standard 10% moisture content for all wood substrates.
Answer: A
Conceptual Explanation: The dry standard is established by measuring a known dry
(unaffected) material to determine the goal for the affected materials.
5. Which class of water intrusion involves the largest amount of water, where materials have
a high constant rate of evaporation (e.g., ceilings, walls, and floors are all saturated)?
A. Class 1
B. Class 2
C. Class 3
D. Class 4
Answer: C
Conceptual Explanation: Class 3 involves the greatest amount of water and the most
surface area of highly porous materials being affected.
6. At what point does wood reach the Fiber Saturation Point (FSP) on average?
A. 15% MC
B. 30% MC
