CRI cheat sheet

Water damage restoration categories: Category 1 is clean water from a sanitary source; Category 2 is gray water with some contamination (washing machine discharge, toilet overflow without solids); Category 3 is grossly contaminated water (sewage, floodwater, toilet trap water) and requires PPE and often disposal of porous materials.

Water damage classes describe evaporation load: Class 1 is minimal absorption with slow evaporation; Class 2 affects an entire room's carpet and pad with 2-5% of surfaces wet; Class 3 involves water from overhead or saturated ceilings and walls; Class 4 involves deep pockets in low-permeability materials such as hardwood, concrete, or subfloor.

Dehumidification sizing: AHAM-based calculations use the class and the cubic footage of the affected area. Class 1 requires about 40% of the pint rating per 100 sq ft; Class 2 about 40%; Class 3 about 60%; Class 4 about 60% plus specialty drying. Always follow the equipment manufacturer's published chart.

Air movers: the general starting point is one air mover per 10-14 linear feet of affected wall, or one per 50-70 sq ft of wet floor area. Place air movers to create a circular airflow pattern around the room to maximize evaporation.

Psychrometric targets: surface temperature must be at least 5-10°F above the dew point of the air to prevent condensation. Keep indoor relative humidity at or below 60% during drying, ideally 40-50%, to keep materials in the drying range.

Extraction is the most important first step: remove as much water as possible before placing equipment. Carpet and pad should be extracted and, if Category 1, can be dried in place; Category 2 and 3 require pad removal and often carpet disposal.

Cleaning agents: detergents emulsify oils and soils; surfactants reduce surface tension; chelating agents bind metal ions; acids dissolve mineral deposits; alkaline cleaners remove grease and organic soils. Match the cleaner to the soil type and material.

Antimicrobials are regulated as pesticides under FIFRA; only use EPA-registered products labeled for the application, and never use them as a substitute for cleaning. Antimicrobials do not sterilize and should not be applied to porous materials that cannot be cleaned.

Moisture meters: pin-type meters measure conductivity and read best on wood and drywall (usually 5-25% MC); pinless meters measure capacitance and read to a depth of about 1 inch, useful for scanning large areas before pin confirmation.

Thermal imaging detects temperature differences from evaporative cooling; a wet area often shows cooler in the morning and warmer in the afternoon. Always confirm thermal anomalies with a moisture meter and do not rely on thermal imaging alone.

Penetrating and non-penetrating moisture meters should be calibrated and referenced against a known dry standard of the same material. Readings on synthetic materials are relative, not moisture content percentages.

Documentation should include a moisture map with readings, a photo log of pre-existing damage, a daily drying log, and a signed work authorization. This documentation is the foundation of insurance claims and dispute resolution.

Mold inspection: look for visible growth, musty odors, water stains, and elevated moisture above 16% MC on wood. Use a borescope to inspect wall cavities and HVAC systems where visible access is limited.

Air sampling for mold is a screening tool, not a clearance test. Spore trap samples show a snapshot of airborne spores; results are compared to an outdoor control sample taken at the same time.

IAQ and health: report conditions, not medical diagnoses. Refer occupants with health concerns to a physician. Do not offer medical advice or interpret lab results as a health risk assessment.

Scope of work: the inspection report defines the affected area, the water category and class, the affected materials, and the recommended drying or remediation approach. A signed scope protects both the contractor and the client.

The drying goal is to return materials to their pre-loss moisture content, typically 10-12% MC for wood framing and 0.5-1% MC for drywall. Monitor daily and adjust equipment based on trends, not a fixed number of days.

Drying chamber: contain the affected area, seal openings, and control the environment. Maintain negative pressure if contamination is present. Do not dry in an unsealed space with high outdoor humidity.

Structural drying of hardwood floors: use drying mats and specialty equipment, keep the floor under controlled airflow, and monitor cupping and crowning. Do not sand until the floor is at its target moisture content.

Category 3 water requires removal of porous materials that cannot be cleaned (carpet, pad, drywall below the flood line), HEPA filtration, and negative air pressure. Clean and disinfect salvageable structural materials with an EPA-registered product.

Reconstruction sequencing: confirm the structure is dry before installing new materials. Installing drywall or flooring over wet framing traps moisture and creates future mold problems.

Fire and smoke restoration: soot is acidic and corrosive; remove it promptly with dry sponges and appropriate cleaners. Use a HEPA vacuum and air scrubbers with carbon filtration to remove smoke odors.

Contents restoration: pack-out inventory, photograph each item, and clean using methods appropriate to the material. Electronics and documents require specialty cleaning and documentation of value.

Post-remediation verification: document moisture readings, visual inspection, and (where required) clearance sampling by an independent party. Do not declare the job complete until the verification is documented.

Moisture is the root cause of mold growth. Remediation is incomplete unless the moisture source is identified and corrected. Mold needs water activity above 0.8 and relative humidity above about 60% to grow.

EPA remediation guidance uses the size of the affected area: less than 10 sq ft is a small job (Level I), 10-100 sq ft is a medium job (Level II), and more than 100 sq ft is a large job (Level III) that typically requires a licensed or certified professional.

Containment: use 6-mil polyethylene and negative air pressure with HEPA-filtered air scrubbers. Maintain a pressure differential of at least 5 Pa (0.02 in. w.c.) so air flows into the containment, not out.

PPE for mold remediation includes an N95 or P100 respirator, goggles, gloves, and disposable coveralls. For large or Category 3 jobs, use a full-face respirator or PAPR.

HEPA vacuums must be rated to 99.97% efficiency at 0.3 microns. Use HEPA vacuuming for final cleaning of surfaces; do not dry-sweep or dry-brush moldy materials because it disperses spores.

Removal: porous materials with mold growth (drywall, insulation, carpet) are generally removed and bagged. Semi-porous and non-porous materials can be cleaned with detergent and water and, where required, an antimicrobial.

Clearance criteria: visual inspection showing no visible mold or dust, moisture readings at dry standard, and (where specified) air sampling results comparable to outdoor control levels. Clearance must be performed by an independent party.

Water damage restoration categories: Category 1 is clean water from a sanitary source; Category 2 is gray water with some contamination (washing machine discharge, toilet overflow without solids); Category 3 is grossly contaminated water (sewage, floodwater, toilet trap water) and requires PPE and often disposal of porous materials.

Water damage classes describe evaporation load: Class 1 is minimal absorption with slow evaporation; Class 2 affects an entire room's carpet and pad with 2-5% of surfaces wet; Class 3 involves water from overhead or saturated ceilings and walls; Class 4 involves deep pockets in low-permeability materials such as hardwood, concrete, or subfloor.

Dehumidification sizing: AHAM-based calculations use the class and the cubic footage of the affected area. Class 1 requires about 40% of the pint rating per 100 sq ft; Class 2 about 40%; Class 3 about 60%; Class 4 about 60% plus specialty drying. Always follow the equipment manufacturer's published chart.

Air movers: the general starting point is one air mover per 10-14 linear feet of affected wall, or one per 50-70 sq ft of wet floor area. Place air movers to create a circular airflow pattern around the room to maximize evaporation.

Psychrometric targets: surface temperature must be at least 5-10°F above the dew point of the air to prevent condensation. Keep indoor relative humidity at or below 60% during drying, ideally 40-50%, to keep materials in the drying range.

Extraction is the most important first step: remove as much water as possible before placing equipment. Carpet and pad should be extracted and, if Category 1, can be dried in place; Category 2 and 3 require pad removal and often carpet disposal.

Cleaning agents: detergents emulsify oils and soils; surfactants reduce surface tension; chelating agents bind metal ions; acids dissolve mineral deposits; alkaline cleaners remove grease and organic soils. Match the cleaner to the soil type and material.

Antimicrobials are regulated as pesticides under FIFRA; only use EPA-registered products labeled for the application, and never use them as a substitute for cleaning. Antimicrobials do not sterilize and should not be applied to porous materials that cannot be cleaned.

Moisture meters: pin-type meters measure conductivity and read best on wood and drywall (usually 5-25% MC); pinless meters measure capacitance and read to a depth of about 1 inch, useful for scanning large areas before pin confirmation.

Thermal imaging detects temperature differences from evaporative cooling; a wet area often shows cooler in the morning and warmer in the afternoon. Always confirm thermal anomalies with a moisture meter and do not rely on thermal imaging alone.

Penetrating and non-penetrating moisture meters should be calibrated and referenced against a known dry standard of the same material. Readings on synthetic materials are relative, not moisture content percentages.

Documentation should include a moisture map with readings, a photo log of pre-existing damage, a daily drying log, and a signed work authorization. This documentation is the foundation of insurance claims and dispute resolution.

Mold inspection: look for visible growth, musty odors, water stains, and elevated moisture above 16% MC on wood. Use a borescope to inspect wall cavities and HVAC systems where visible access is limited.

Air sampling for mold is a screening tool, not a clearance test. Spore trap samples show a snapshot of airborne spores; results are compared to an outdoor control sample taken at the same time.

IAQ and health: report conditions, not medical diagnoses. Refer occupants with health concerns to a physician. Do not offer medical advice or interpret lab results as a health risk assessment.

Scope of work: the inspection report defines the affected area, the water category and class, the affected materials, and the recommended drying or remediation approach. A signed scope protects both the contractor and the client.

The drying goal is to return materials to their pre-loss moisture content, typically 10-12% MC for wood framing and 0.5-1% MC for drywall. Monitor daily and adjust equipment based on trends, not a fixed number of days.

Drying chamber: contain the affected area, seal openings, and control the environment. Maintain negative pressure if contamination is present. Do not dry in an unsealed space with high outdoor humidity.

Structural drying of hardwood floors: use drying mats and specialty equipment, keep the floor under controlled airflow, and monitor cupping and crowning. Do not sand until the floor is at its target moisture content.

Category 3 water requires removal of porous materials that cannot be cleaned (carpet, pad, drywall below the flood line), HEPA filtration, and negative air pressure. Clean and disinfect salvageable structural materials with an EPA-registered product.

Reconstruction sequencing: confirm the structure is dry before installing new materials. Installing drywall or flooring over wet framing traps moisture and creates future mold problems.

Fire and smoke restoration: soot is acidic and corrosive; remove it promptly with dry sponges and appropriate cleaners. Use a HEPA vacuum and air scrubbers with carbon filtration to remove smoke odors.

Contents restoration: pack-out inventory, photograph each item, and clean using methods appropriate to the material. Electronics and documents require specialty cleaning and documentation of value.

Post-remediation verification: document moisture readings, visual inspection, and (where required) clearance sampling by an independent party. Do not declare the job complete until the verification is documented.

Moisture is the root cause of mold growth. Remediation is incomplete unless the moisture source is identified and corrected. Mold needs water activity above 0.8 and relative humidity above about 60% to grow.

EPA remediation guidance uses the size of the affected area: less than 10 sq ft is a small job (Level I), 10-100 sq ft is a medium job (Level II), and more than 100 sq ft is a large job (Level III) that typically requires a licensed or certified professional.

Containment: use 6-mil polyethylene and negative air pressure with HEPA-filtered air scrubbers. Maintain a pressure differential of at least 5 Pa (0.02 in. w.c.) so air flows into the containment, not out.

PPE for mold remediation includes an N95 or P100 respirator, goggles, gloves, and disposable coveralls. For large or Category 3 jobs, use a full-face respirator or PAPR.

HEPA vacuums must be rated to 99.97% efficiency at 0.3 microns. Use HEPA vacuuming for final cleaning of surfaces; do not dry-sweep or dry-brush moldy materials because it disperses spores.

Removal: porous materials with mold growth (drywall, insulation, carpet) are generally removed and bagged. Semi-porous and non-porous materials can be cleaned with detergent and water and, where required, an antimicrobial.

Clearance criteria: visual inspection showing no visible mold or dust, moisture readings at dry standard, and (where specified) air sampling results comparable to outdoor control levels. Clearance must be performed by an independent party.