Free IICRC WRT Practice Exam with Questions & Answers | Set: 2

The IICRC WRT body of knowledge teaches that initial dehumidification capacity for LGR dehumidifiers is based oncubic footage and class of water intrusion. Class 2 intrusions involve a larger amount of moisture absorption than Class 1 but do not reach the full saturation of Class 3.

First, calculate the affected volume:

1,300 sq ft × 8 ft =10,400 cubic feet.

ForClass 2 losses, a commonly accepted WRT guideline is approximatelyone LGR dehumidifier (≈200–210 PPD)per10,000–12,000 cubic feet. This capacity balances evaporation demand without over-drying or inefficiency.

A recommendation of 208 PPD aligns directly with this guidance and reflects standard WRT training tables used for initial equipment placement. Lower values (26 or 99 PPD) are insufficient for the moisture load, while 303 PPD exceeds the initial requirement for a Class 2 loss and would require justification through monitoring data.

The WRT manual emphasizes that this is aninitial recommendationand must be validated by daily psychrometric and material moisture monitoring. Equipment may be adjusted as drying progresses.

The IICRC WRT body of knowledge explains thatlow-grain refrigerant (LGR) dehumidifiersare designed to remove moisture more efficiently at lower humidity ratios than conventional refrigerant dehumidifiers. As a result, LGR units can reduceair vapor pressure to lower levelsthan standard refrigerant systems under similar conditions.

This enhanced capability allows LGR dehumidifiers to continue removing moisture even as the environment becomes drier, supporting faster and more complete drying. The WRT manual highlights this feature as a key advantage of LGR technology in most residential and light commercial drying scenarios.

LGR units do not operate effectively at freezing temperatures, are not optimized for extreme heat, and cannot achieve vapor pressure levels lower than desiccant systems. Desiccants remain superior for very low humidity or low-temperature conditions.

Therefore, the correct benefit under WRT guidance is the ability of LGR dehumidifiers to reduce vapor pressure lower than conventional refrigerant dehumidifiers.

The IICRC WRT body of knowledge explains thataerosolization of contaminantsoccurs when airflow disperses particulate matter, microorganisms, or contaminated droplets into the air. To reduce this risk, restorers shouldminimize air movementin contaminated areas until proper controls are in place.

In Category 2, Category 3, or mold-affected environments, uncontrolled airflow can spread contaminants beyond the affected area, increasing exposure risk and cross-contamination. The WRT manual emphasizes that airflow should be strategically managed and often delayed until containment and air filtration devices (AFDs) are installed.

Increasing air movement or temperature without controls can worsen aerosolization. Temperature reduction alone does not address particulate dispersion. Minimizing air movement—combined with containment and filtration—is the recommended approach under WRT safety principles.

The IICRC WRT body of knowledge states thatcarpet affected by Category 3 water is not restorableand must be removed and discarded due to gross contamination. However, when a materially interested party disputes this requirement, the restorer muststop work until the conflict is resolved.

Proceeding against the expressed objection of an owner, occupant, or insurer exposes the restorer to legal and financial liability. The WRT manual emphasizes that restorers must not perform disputed work without proper authorization, even when technical standards clearly indicate removal is required.

Cleaning, saving, or applying additional antimicrobials does not make Category 3-affected carpet safe or compliant with IICRC standards. Antimicrobials cannot neutralize sewage-level contamination embedded within porous materials.

Stopping work allows time for consultation, documentation, expert input, or formal dispute resolution. This approach protects all parties and maintains professional integrity while adhering to health and safety principles.

The IICRC WRT body of knowledge states that moisture detection instruments allow restorers to evaluate and documentpsychrometric conditions and moisture content or moisture level readings. These measurements form the foundation of drying verification and defensible documentation.

Moisture meters measure moisture within materials, while thermo-hygrometers capture air temperature and relative humidity, enabling calculation of dew point, humidity ratio, and vapor pressure. Together, these tools allow restorers to assess drying effectiveness, establish drying goals, and demonstrate progress over time.

Thermal imaging provides indirect information and must be verified, while manometers and particulate counters serve specialized purposes outside routine moisture documentation.

The WRT manual emphasizes consistent measurement, proper instrument selection, and clear documentation as essential components of professional restoration practice and project closeout.

The IICRC WRT body of knowledge clearly states that a restorer must inspectall potentially affected areasin a water-damaged structure. Water migration is often hidden and does not always follow visible or obvious paths. Gravity, capillary action, air movement, and building assemblies can allow water to spread far beyond the area initially identified by occupants.

The WRT manual emphasizes that relying solely on visible water, odors, or customer statements is insufficient and can result in missed moisture, incomplete drying, and secondary damage. Hidden moisture may exist behind walls, under flooring, inside cabinets, beneath insulation, or in adjacent rooms not immediately associated with the loss.

A comprehensive inspection includes visual assessment, moisture detection instruments, infrared imaging (verified with meters), and evaluation of building construction features that may facilitate water movement. This approach ensures accurate scoping, proper classification, and effective drying system design.

Inspecting all potentially affected areas aligns with the ANSI/IICRC S500 Standard’s requirement for thorough evaluation and defensible documentation, reducing the risk of undiscovered moisture and future claims.

The IICRC WRT body of knowledge explains that drying restorable subflooring beneath ceramic tile is challenging because tile and grout assemblies havelow permeability, restricting vapor movement. In such conditions, evaporation must be enhanced by manipulating the remaining controllable variables—most notablytemperature.

Increasing the temperature of the wet materials raises the vapor pressure within the subfloor, which increases the vapor pressure differential between the material and the surrounding air. This differential is the primary driving force that moves moisture out of materials and into the air. The WRT manual emphasizes that warmer materials evaporate moisture more readily, provided ambient air vapor pressure remains lower.

Lowering dehumidifier output temperature or increasing relative humidity would reduce drying efficiency. Air filtration devices address airborne particulates and do not directly influence evaporation. Therefore, controlled heat application—within safe limits—is a recommended strategy when drying beneath low-permeance floor coverings.

The WRT curriculum reinforces that effective drying requires managinghumidity, airflow, and temperature together, particularly when materials restrict vapor transmission.

The IICRC WRT body of knowledge recommends the use ofAir Filtration Devices (AFDs)to minimize and control airborne contaminants during restoration activities. AFDs equipped with HEPA filtration capture airborne particulates, including dust, microbial fragments, and other contaminants generated during mitigation.

The WRT manual explains that uncontrolled airborne contaminants can pose health risks to workers and occupants and can spread contamination to unaffected areas. AFDs reduce this risk by continuously filtering air and, when properly configured, creating negative pressure within containment zones.

Dehumidifiers manage moisture, not particulates. Air movers can increase aerosolization if used improperly. HVAC systems are not designed for contamination control during restoration and may spread contaminants throughout the structure.

AFDs are therefore the recommended engineering control for airborne contaminant management under the WRT standard of care.

Condensation occurs when a surface temperature reaches or drops below thedew point temperatureof the surrounding air. The IICRC WRT body of knowledge emphasizes that dew point—not relative humidity alone—determines when condensation will form.

At90°F and 60% RH, the corresponding dew point is approximately74°F. Any surface at or below this temperature will experience condensation as water vapor changes phase from gas to liquid.

This principle is critical in restoration drying because unintended condensation can re-wet materials and cause secondary damage. The WRT curriculum trains restorers to monitor both air dew point and material surface temperatures to prevent this condition.

Lower temperature options listed would represent colder surfaces but condensation would already occur once the surface reaches the dew point. Therefore, 74°F is the correct threshold.

The IICRC WRT body of knowledge states that wastewater generated during water damage restoration must be disposed ofin accordance with applicable local, state, and federal laws and regulations. Wastewater may contain contaminants, sediments, microorganisms, or chemical residues, and improper disposal can create environmental and public health risks.

The WRT manual emphasizes that restorers are responsible for understanding disposal requirements within the jurisdiction where work is performed. These requirements may regulate where wastewater can be discharged (e.g., sanitary sewer systems) and prohibit disposal into storm drains, onto soil, or into surface waters. Disposal practices may also vary depending on contamination category, such as sewage or chemically contaminated water.

OSHA regulations focus on worker safety, not wastewater disposal. AHAM standards apply to appliance performance testing, not environmental disposal. ANSI/IICRC S520 addresses mold remediation, not wastewater handling. Therefore, none of those documents define wastewater disposal requirements.

By following applicable laws and regulations, restorers ensure environmental compliance, protect public infrastructure, and reduce legal liability. This requirement reflects the WRT emphasis on regulatory awareness and responsible professional conduct.