IICRC Water Damage Restoration Technician (WRT) WRT Exam Dumps: Updated Questions & Answers (February 2026)

The IICRC WRT body of knowledge identifiesrelative humidity at or above approximately 70%as presenting the greatest risk for structural and microbial damage to hygroscopic materials. At this level, many materials readily absorb moisture from the air, increasing moisture content even without direct liquid water contact.

The WRT manual explains that hygroscopic materials such as wood, paper, drywall, and textiles reach higher equilibrium moisture contents as RH increases. When RH exceeds safe thresholds, these materials may swell, deform, lose structural integrity, or support microbial growth.

Microbial amplification risk also increases significantly at higher RH levels. While mold growth depends on multiple factors, sustained RH above approximately 60–70% greatly increases the likelihood of microbial activity on organic materials.

This is why restorers are trained to aggressively control humidity during drying and to monitor RH as part of daily documentation. Maintaining RH well below damaging thresholds protects unaffected materials and limits secondary damage during the restoration process.

The IICRC WRT body of knowledge teaches that the suitability of outdoor air for ventilation drying depends onhumidity ratio, not relative humidity alone. The best outdoor air conditions are those with thelowest humidity ratio, allowing moisture to be removed from the indoor environment.

Among the options,70°F and 30% RHhas the lowest humidity ratio, making it the most effective for ventilation. Low humidity ratio air reduces indoor vapor pressure and supports evaporation without introducing excess moisture.

High relative humidity—even at cooler temperatures—often carries more moisture than drier warm air. The WRT manual cautions restorers against using outdoor air based solely on comfort perception. Psychrometric comparison is required.

Using inappropriate outdoor air can increase indoor moisture levels and slow drying. Therefore, option C represents the best condition under WRT principles.

The IICRC WRT body of knowledge explains thatrelative humidity decreaseswhen air temperature increases and no additional moisture is added. This occurs because warmer air can hold more water vapor; therefore, the same amount of moisture represents a smaller percentage of the air’s total capacity.

This principle is foundational in psychrometry and directly applied in restoration drying. By increasing temperature while controlling moisture content, restorers lower relative humidity and vapor pressure, increasing evaporation potential.

Relative humidity does not remain constant with temperature changes, nor does it increase unless moisture is added. Dew point remains unchanged unless moisture content changes.

Understanding this relationship allows restorers to use controlled heat strategically to improve drying efficiency without introducing excess moisture.

The IICRC WRT body of knowledge states that verification of drying completion must be supported byobjective, measurable documentation. This includesmoisture content or moisture level records,moisture maps, anddocumented drying conditionssuch as temperature, relative humidity, humidity ratio, and dew point.

These records demonstrate that affected materials were dried to established drying goals, typically based on comparison with unaffected reference materials. The WRT manual emphasizes that documentation must show trends over time, not just final readings, to confirm effective drying.

Electrical usage records, contracts, or remediation protocols alone do not verify drying success. While they may be relevant administratively, they do not demonstrate moisture removal.

Comprehensive drying documentation is essential for transparency, defensibility, and compliance with the ANSI/IICRC S500 Standard and is a cornerstone of professional restoration practice.

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 identifiesdesiccant dehumidification systemsas capable of creating thelowest vapor pressurein a drying environment. Desiccant systems remove moisture through adsorption, allowing them to achieve extremely low humidity ratios and vapor pressures—lower than refrigerant-based systems can typically reach.

Because vapor pressure drives moisture movement, achieving very low air vapor pressure significantly increases the drying potential for dense or low-permeance materials. This is why desiccant systems are often specified for Class 4 drying, cold environments, or situations requiring aggressive moisture removal.

Heat-only systems increase vapor pressure unless paired with moisture removal. Inter-air systems enhance airflow but do not independently reduce vapor pressure. LGR dehumidifiers reduce vapor pressure effectively but not to the same extent as desiccants.

The WRT curriculum emphasizes that system selection must be based on drying objectives and material characteristics, with desiccants reserved for scenarios requiring maximum vapor pressure reduction.

Vapor pressureis defined in the IICRC WRT body of knowledge as the force exerted by water vapor molecules in the air against surrounding surfaces. It represents the energy level of moisture in the air and is a key driver of moisture movement.

The WRT manual explains that water vapor moves from areas of higher vapor pressure to areas of lower vapor pressure, whether between materials and air or between different air masses. This principle governs evaporation, condensation, and moisture redistribution within a drying chamber.

Relative humidity describes a percentage relationship, humidity ratio measures moisture mass, and dew point identifies saturation temperature—but vapor pressure quantifies the actualdriving force. Because vapor pressure is directly influenced by both temperature and humidity ratio, it is considered one of the most precise indicators of drying potential.

Effective drying systems focus on lowering air vapor pressure relative to wet materials, ensuring continuous moisture migration out of structural components.

The IICRC WRT body of knowledge identifies apower stretcher and knee kickeras the primary tools used to properly disengage and reinstall most stretched-in carpet systems. These tools are designed to safely release carpet from tack strips without tearing the backing or damaging the carpet edges.

A knee kicker is commonly used to disengage carpet along edges and corners by applying controlled force. A power stretcher is then used during reinstallation to properly tension the carpet across the room, preventing wrinkles, buckling, or future failure.

The WRT manual emphasizes that improper disengagement—such as pulling carpet by hand or using pliers—can cause delamination, backing damage, or seam separation. Such damage may be considered avoidable secondary damage and create liability for the restorer.

Carpet awls and molding lifters serve other purposes but are not sufficient for disengaging stretched-in carpet. Proper tool use ensures that restorable carpet can be safely lifted for drying and returned to service when conditions allow.

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.

According to the IICRC WRT body of knowledge, theinitial dehumidification capacity recommendationis determined by three primary factors:cubic footage of the affected area,class of water intrusion, andtype of dehumidifierbeing used. This calculation establishes a baseline moisture removal capability required to manage the anticipated evaporation load.

Cubic footage defines the volume of air within the drying chamber and directly influences how much moisture must be removed from the environment. Theclass of waterdescribes how much moisture has been absorbed by materials and the rate of evaporation expected. Higher classes (Class 3 and 4) require substantially more dehumidification capacity due to increased moisture loading and deeply absorbed water.

Thetype of dehumidifieris equally critical because different technologies (conventional refrigerant, LGR, desiccant) have vastly different operating ranges, efficiencies, and moisture removal characteristics. The WRT manual specifically differentiates capacity calculations for LGR versus desiccant systems, as they function under different psychrometric conditions.

Factors such as category of water, subfloor type, or air mover quantity influenceprocedural decisions, safety, and drying strategy—but they are not part of the initial capacity calculation. Likewise, grain depression is a performance outcome used for evaluation, not an input variable.

This structured approach ensures consistency, defensibility, and alignment with the ANSI/IICRC S500 Standard, enabling restorers to justify equipment placement using measurable, science-based criteria rather than guesswork or habit.