IICRC APPLIED STRUCTURAL DRYING
UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS COMPREHENSIVE
STUDY GUIDE FULL SOLUTION
●● Air Filtration Device
Answer: AFD
●● Assembly Construction
Answer: Prior to determining the best drying system for affected
materials, restorers should identify and understand the assembly
construction (ie wall assembly, floor assembly)
●● Category 1
Answer: water originates from a sanitary source and does not pose
substantial risk for dermal, ingestion, inhalation, or exposure.
Uncontaminated and routinely cleaned
●● Category 2
Answer: water contains significant contamination and has the potential
to cause discomfort or sickness if contacted or consumed by humans
●● Category 3
,Answer: water is grossly contaminated and can contain pathogenic,
toxigenic, or other harmful agents
●● Sewage Back Up
Answer: Category 3
●● Clean water supply line
Answer: Category 1
●● Class 1
Answer: Least amount of water absorption and evaporation load - Wet
porous materials - water loss is less then 5% of the area
●● Class 2
Answer: Significant amount of water absorption and evaporation load -
water intrusion where wet represents 5% - 40% of the area.
●● Class 3
Answer: greatest amount of water absorption and evaporation load.
Water intrusion where wet represents over 40% of the area
●● Class 4
, Answer: deeply held or bound water. Significant amount of water
absorption into low evaporation materials. Drying may require special
drying methods, longer drying time, or substantial water vapor pressure
differentials.
●● Closed drying system
Answer: Uses mechanical dehumidification and is not open to outside
air. Used if there are security issues, the outside air is not conductive to
drying or when access to outside air is not possible.
●● Conventual refrigerant dehumidifier
Answer: Removes water vapor from the air by lowering the temperature
of the incoming air to below dew point and causing the water to
condense on the coils. Cold and hot surfaces created with gases inside a
closed coil system.
●● Combination Drying System
Answer: uses some outdoor air with dehumidifiers to accelerate the
drying process. This can include periodically venting (flushing) the
structure, using negative pressure or using small openings to the outside
●● Desiccant dehumidifier
Answer: Removes water vapor from the air through absorption. Usually
requires more amperage as compared to refrigerant dehumidifier.
Desiccants create the lowest vapor pressure which work best on low
porosity materials. When a desiccant dehu is drawing outside air and
UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS COMPREHENSIVE
STUDY GUIDE FULL SOLUTION
●● Air Filtration Device
Answer: AFD
●● Assembly Construction
Answer: Prior to determining the best drying system for affected
materials, restorers should identify and understand the assembly
construction (ie wall assembly, floor assembly)
●● Category 1
Answer: water originates from a sanitary source and does not pose
substantial risk for dermal, ingestion, inhalation, or exposure.
Uncontaminated and routinely cleaned
●● Category 2
Answer: water contains significant contamination and has the potential
to cause discomfort or sickness if contacted or consumed by humans
●● Category 3
,Answer: water is grossly contaminated and can contain pathogenic,
toxigenic, or other harmful agents
●● Sewage Back Up
Answer: Category 3
●● Clean water supply line
Answer: Category 1
●● Class 1
Answer: Least amount of water absorption and evaporation load - Wet
porous materials - water loss is less then 5% of the area
●● Class 2
Answer: Significant amount of water absorption and evaporation load -
water intrusion where wet represents 5% - 40% of the area.
●● Class 3
Answer: greatest amount of water absorption and evaporation load.
Water intrusion where wet represents over 40% of the area
●● Class 4
, Answer: deeply held or bound water. Significant amount of water
absorption into low evaporation materials. Drying may require special
drying methods, longer drying time, or substantial water vapor pressure
differentials.
●● Closed drying system
Answer: Uses mechanical dehumidification and is not open to outside
air. Used if there are security issues, the outside air is not conductive to
drying or when access to outside air is not possible.
●● Conventual refrigerant dehumidifier
Answer: Removes water vapor from the air by lowering the temperature
of the incoming air to below dew point and causing the water to
condense on the coils. Cold and hot surfaces created with gases inside a
closed coil system.
●● Combination Drying System
Answer: uses some outdoor air with dehumidifiers to accelerate the
drying process. This can include periodically venting (flushing) the
structure, using negative pressure or using small openings to the outside
●● Desiccant dehumidifier
Answer: Removes water vapor from the air through absorption. Usually
requires more amperage as compared to refrigerant dehumidifier.
Desiccants create the lowest vapor pressure which work best on low
porosity materials. When a desiccant dehu is drawing outside air and
