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Classes of Water Loss

If your home has recently suffered water damage or a water-related disaster, determining the classes of water loss is an important step in beginning water damage restoration. Identifying the classes of water loss enables restoration professionals to formulate a plan based on your home's specific needs.

Classes of Water Loss
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  • Classes of water loss refer to the amount of water and the anticipated rate of evaporation based on the amount and type of wet materials in your home. There are four classes of water loss:

    Class 1: Slow Rate of Evaporation

    A class one water loss affects only part of a room with low-permeance or low-porosity materials such as particle board, plywood, structural wood, vinyl composition tile, and concrete. Learn more.

    Class 2: Fast Rate of Evaporation

    Class two water losses affect the whole room and materials such as carpet and cushions. The seepage of water up walls is less than 24 inches, and moisture remains in structural materials. Learn more.

    Class 3: Fastest Rate of Evaporation

    Class three water losses typically come from overhead, saturating insulation, ceilings, walls, carpet, cushion, and subfloor in virtually the entire area. Learn more.

    Class 4: Specialty Drying Situations

    Specialty drying situations involve wet materials with very low permeance or low porosity. Examples include hardwood, plaster, brick, concrete, stone, subfloors and crawlspaces. Learn more.

Water Damage Restoration, Water Damage Cleanup, Flooding, Burst Pipe, Chicago.

Categories of Water Damage


In addition to identifying the classes of water loss, it is also important to identify the state of the water affecting the damaged materials. Simply put, how clean or dirty is it? There are three categories of water damage:

Category 1: Sanitary Liquids

These liquids are from sanitary sources such as faucets and toilet tanks, but they can quickly degrade into category two liquids.

Category 2: Grey Water

These liquids come from sources such as dishwashers, washing machines, sink drains, and toilet overflow (urine only), and contain contaminants that may cause illness or discomfort if ingested.

Category 3: Black Water

These grossly unsanitary liquids include sewage backup, feces-contaminated toilet overflow, flooding from rivers or streams, and bacteria-laden stagnant liquid, which can cause severe illness or death if ingested.

Giving your Rainbow Restoration® technician accurate information about the water damage in your home ensures your restoration team will bring with it the right tools and expertise for restoring your home to its pre-damaged state. For a speedy, safe resolution to water damage to your home, contact Rainbow Restoration. RainbowRestoration is IICRC (Institute of Inspection, Cleaning and Restoration Certification) certified and is on-call 24 hours a day, 7 days a week to help get your home and your life back on track following damage from water, fire, smoke, mold, and more.