IICRC - Applied Structural Drying Exam
Questions and Answers (Solved
Papers)latest update 2025/2026 RATED A+
Commonly called an air scrubber or negative air machine if airborne particles need to be reduced, you
could use an appropriately installed _______ ________ ________ - CORRECT ANSWERS Air
Filtration Device (ADF)
AFD - CORRECT ANSWERS Air Filtration Device
Prior to determining the best drying system for affected materials, restorers should identify and
understand the assembly construction (ie wall assembly, floor assembly) - CORRECT ANSWERS
Assembly Construction
water originates from a sanitary source and does not pose substantial risk for dermal, ingestion,
inhalation, or exposure. Uncontaminated and routinely cleaned - CORRECT ANSWERS Category
1
water contains significant contamination and has the potential to cause discomfort or sickness if
contacted or consumed by humans - CORRECT ANSWERS Category 2
water is grossly contaminated and can contain pathogenic, toxigenic, or other harmful agents - CORRECT
ANSWERS Category 3
Category 3 - CORRECT ANSWERS Sewage Back Up
Category 1 - CORRECT ANSWERS Clean water supply line
Least amount of water absorption and evaporation load - Wet porous materials - water loss is less then
5% of the area - CORRECT ANSWERS Class 1
,Significant amount of water absorption and evaporation load - water intrusion where wet represents 5%
- 40% of the area. - CORRECT ANSWERS Class 2
greatest amount of water absorption and evaporation load. Water intrusion where wet represents over
40% of the area - CORRECT ANSWERS Class 3
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. - CORRECT ANSWERS Class 4
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. - CORRECT
ANSWERS Closed drying system
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. - CORRECT ANSWERS Conventual refrigerant dehumidifier
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 -
CORRECT ANSWERS Combination Drying System
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 ducting processed air inside a building it
can create positive pressure in the building. To improve desiccant dehu performance, it may be
beneficial to pre-cool the desiccants air intake - CORRECT ANSWERS Desiccant dehumidifier
High humidity outside air could affect the drying climate adversely due to ______________ - CORRECT
ANSWERS Infiltration
, Favors that affect the detailed dehumidifier calculation is: - CORRECT ANSWERS 1. Tightness of
the building envelope
2. Prevailing weather
3. HVAC
4. Class of Water
5. Building Construction
5. Build out density
See Chart:
Cubic Feet : Divided by 70 = Base Pints per day
Multiply the 5 multipliers together: Build out density x building construction x class of water x HVAC x
Weather Impact = Multiplier
Multiply Base Pints per day x Multiplier = Adjusted Pints Per Day - CORRECT ANSWERS Detailed
Dehumidification Calculation
The unaffected material readings are called ______ ______. You know you can use this as your drying
goal. Your drying goal is this plus 10% of it. - CORRECT ANSWERS Dry Standards
Dry standard + (Dry standard x 10%) = ____________________ - CORRECT ANSWERS Drying
Goal Calculation
1. Removing Materials to eliminate safety hazards
2. Removing materials that have suffered primary damage and are not restorable
3. Removing porous materials that are holding odor
5. Removing vapor barriers to assist with drying efforts
6. Removing materials to reduce drying time
Questions and Answers (Solved
Papers)latest update 2025/2026 RATED A+
Commonly called an air scrubber or negative air machine if airborne particles need to be reduced, you
could use an appropriately installed _______ ________ ________ - CORRECT ANSWERS Air
Filtration Device (ADF)
AFD - CORRECT ANSWERS Air Filtration Device
Prior to determining the best drying system for affected materials, restorers should identify and
understand the assembly construction (ie wall assembly, floor assembly) - CORRECT ANSWERS
Assembly Construction
water originates from a sanitary source and does not pose substantial risk for dermal, ingestion,
inhalation, or exposure. Uncontaminated and routinely cleaned - CORRECT ANSWERS Category
1
water contains significant contamination and has the potential to cause discomfort or sickness if
contacted or consumed by humans - CORRECT ANSWERS Category 2
water is grossly contaminated and can contain pathogenic, toxigenic, or other harmful agents - CORRECT
ANSWERS Category 3
Category 3 - CORRECT ANSWERS Sewage Back Up
Category 1 - CORRECT ANSWERS Clean water supply line
Least amount of water absorption and evaporation load - Wet porous materials - water loss is less then
5% of the area - CORRECT ANSWERS Class 1
,Significant amount of water absorption and evaporation load - water intrusion where wet represents 5%
- 40% of the area. - CORRECT ANSWERS Class 2
greatest amount of water absorption and evaporation load. Water intrusion where wet represents over
40% of the area - CORRECT ANSWERS Class 3
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. - CORRECT ANSWERS Class 4
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. - CORRECT
ANSWERS Closed drying system
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. - CORRECT ANSWERS Conventual refrigerant dehumidifier
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 -
CORRECT ANSWERS Combination Drying System
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 ducting processed air inside a building it
can create positive pressure in the building. To improve desiccant dehu performance, it may be
beneficial to pre-cool the desiccants air intake - CORRECT ANSWERS Desiccant dehumidifier
High humidity outside air could affect the drying climate adversely due to ______________ - CORRECT
ANSWERS Infiltration
, Favors that affect the detailed dehumidifier calculation is: - CORRECT ANSWERS 1. Tightness of
the building envelope
2. Prevailing weather
3. HVAC
4. Class of Water
5. Building Construction
5. Build out density
See Chart:
Cubic Feet : Divided by 70 = Base Pints per day
Multiply the 5 multipliers together: Build out density x building construction x class of water x HVAC x
Weather Impact = Multiplier
Multiply Base Pints per day x Multiplier = Adjusted Pints Per Day - CORRECT ANSWERS Detailed
Dehumidification Calculation
The unaffected material readings are called ______ ______. You know you can use this as your drying
goal. Your drying goal is this plus 10% of it. - CORRECT ANSWERS Dry Standards
Dry standard + (Dry standard x 10%) = ____________________ - CORRECT ANSWERS Drying
Goal Calculation
1. Removing Materials to eliminate safety hazards
2. Removing materials that have suffered primary damage and are not restorable
3. Removing porous materials that are holding odor
5. Removing vapor barriers to assist with drying efforts
6. Removing materials to reduce drying time
