IICRC - Applied Structural Drying
2025/2026 Exam Questions and Verified
Answers | Already Graded A+
Air Filtration Device (ADF) - 🧠 ANSWER ✔✔Commonly called an air
scrubber or negative air machine if airborne particles need to be reduced,
you could use an appropriately installed _______ ________ ________
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
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
1
,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.
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
2
, 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 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
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
3
2025/2026 Exam Questions and Verified
Answers | Already Graded A+
Air Filtration Device (ADF) - 🧠 ANSWER ✔✔Commonly called an air
scrubber or negative air machine if airborne particles need to be reduced,
you could use an appropriately installed _______ ________ ________
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
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
1
,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.
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
2
, 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 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
COPYRIGHT©NINJANERD 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
3
