Upon signing a contract to dry down a water-affected space, the first step is to determine if the project’s restoration team will need to apply the procedures for Category 1, 2 or 3 losses according to the IICRC S500 2021 edition. Each category describes differing degrees of contamination, directly governing the restoration processes to be performed before structural drying is started.
Let's break down the essentials of these water damage categories to provide the basics for restoring flood-damaged areas safely and effectively.
How Is Water Damage Categorized?
Typically the water loss category is determined by the restoration company once it has access to the loss (unless an indoor environmental professional has been hired to determine the Category). Understanding flood water's source and initial degree of contamination is a crticial first step, but the water source is not the only factor that determines whether a job will be processed as Category 1, 2, or 3.
Pre-existing Contamination: Clean water flooding into an uncontaminated building will be processed as a Category 1 water loss, assuming that the drying contractor is able to take action immediately. However, if clean water mixes with filth in the building, it must be handled as a contaminated category (Category 2 or 3).
Time Since Water Exposure and Odors: Water degrades over time – in cool temperatures, at a lesser rate; in warmer temperatures, at a greater rate. Given a long enough period, even water from a clean source will degrade to a contaminated category. One evidence of this is foul odors. For the same reasons, a job that has been flooded from a Category 2 source can degrade to a Category 3 contamination level.
Category 1:
Often referred to as "clean," Category 1 water comes from a sanitary source and poses no substantial health risks. Examples include water from:
A Category 1 water loss offers the best opportunity for the greatest amount of finishing materials (gypsum wallboard, restorable floor coverings) to be saved while the structure is being dried out by skilled restorative drying contractors.
Category 2:
This water category contains a significant level of chemical, biological or physical contamination. Exposure to the microorganisms in this water can cause sickness or discomfort. Common sources include:
Restoration for Category 2 water requires some materials' removal and cleaning steps before drying begins. For example, certain affected materials like carpet padding and gypsum wallboard must be removed and discarded, followed by washing and rinsing of the affected structure. Hospital grade disinfectants are often applied as part of the cleaning process to remove risks from contamination.
Category 3:
When it’s determined that water is Category 3, that means water is grossly contaminated and poses serious health risks including disease. This type of water may contain harmful pathogens, sewage or toxic substances. Sources include:
When dealing with Category 3 water, personal protective equipment (PPE) such as gloves, boots, respirators and protective clothing, is mandatory. The same Category 2 procedures as described above are required on Category 3 losses (removal of highly porous materials, then thorough cleaning, rinsing and application of hospital grade disinfectants before drying). A follow-up article will further define the procedural differences between Category 2 and 3 projects.
Why Understanding Water Categories Is Important
Properly identifying the water damage category determines the cleaning and mitigation methods and safety protocols necessary for effective restoration. Misclassifying water can lead to insufficient flood cleanup, potentially endangering both property and the health of occupants. For example, treating Category 3 water as if it were Category 1 would result in long-term legal liabilities since severe contamination would be left behind in the building.
Key Advice for Beginners
Be Prepared to Respond Quickly: The category of water can worsen over time, so a fast response time and thorough water extraction are essential.
Use the Right Equipment: Extract flood water quickly and thoroughly using a commercial flood pumper, such as a Sapphire Scientific® truckmount or the Dri-Eaz HVE 3000 portable extractor. Carefully inspect and map the extent of moisture migration using high-quality moisture meters to ensure that the drying system encompasses all wet materials and assemblies.
Follow Regulations and Stay Safe: Comply with federal, state and local laws and abide by IICRC S500 guidelines regarding contamination removal, cleaning and biocide use. Wear protective gear and use Mediclean® EPA-registered antimicrobials per label instructions and according to company policies.
Continue Learning: Obtain IICRC Water Restoration Technician (WRT), Applied Structural Drying (ASD) and Applied Microbial Remediation Technician (AMRT) certifications. Online WRT courses, hands-on 3-day ASD and 5-day WRT/ASD combination courses offered through Restoration Sciences Academy make it easy to ensure that all technicians are trained and certified.
Mastering the basics of determining water damage categories allows you to approach restoration projects with confidence while complying with professional standards. Remember that each category requires a unique response, and the safety of both the property and its occupants and eliminating risk from contamination depends on your knowledge and skills in applying all of the appropriate procedures per category.
For more restoration-related guidance, search our Tips & Tricks for "dry" or other topics of interest.
