Drying Guidelines

Categories of Water Damage:

In order to better understand the nature of water damage, and before professional restorers begin processing water-damaged structures and materials safely, they must be aware of and consider the categories of water sources. According to the IICRC (Institute of Inspection, Cleaning and Restoration Certification) Standard and Reference Guide for Professional Water Damage Restoration S500 Second Edition, water is divided into three general categories:

A. Category 1, often referred to as “clean” water

A “clean” water source is one that does not pose substantial harm to humans. Examples of clean water sources may include, but are not limited to: broken water supply lines, tub or sink overflows with no contaminants, appliance malfunctions involving water supply lines, melting ice or falling rainwater – not that which flows over the soil or through multiple structural components – broken toilet tanks, and even toilet bowls that do not contain contaminants or additives. Once a clean water source contacts other surfaces and materials, its condition may change as it dissolves or mixes with soils and other contaminants, and as time elapses.

B. Category 2, often referred to as “gray” water

Unsanitary or “gray” water contains some degree of contamination. Potentially, it could cause substantial discomfort or sickness if consumed by humans, and it carries microorganisms or nutrients for microorganisms. Category 2 (gray) water examples may include, but are not limited to: discharge from dishwashers or washing machines, overflows from washing machines, toilet bowls with some urine (no feces), broken aquariums, and punctured water beds. All of these may contain chemicals or Bio-contaminants (fungal, bacterial, viral, algae), or other forms of contamination. Time and temperature aggravate Category 2 (gray) water contamination significantly. Water in flooded structures that remain untreated longer than 48 hours can change from Category 2 (gray) to Category 3 (black).

Carpet and drywall may be restored in a category 2 loss. Cushion should be removed.

C. Category 3, often referred to as “black” water

“Black” water always contains pathogenic agents. Grossly unsanitary or “black” water sources are those that arise from sewage or other contaminated water entering a structure. Sewage contains the expected urine and feces; but it also could contain dangerous chemicals or medical wastes. Toilet back flows that originate from beyond the toilet trap are considered to be Category 3 (black) water situations, regardless of visible content or color. This category includes all forms of sea water, ground surface water, and rising water from rivers or streams. They carry silt and organic matter into structures and create Category 3 (black) water situations. In situations where materials such as pesticides, heavy metals, or toxic organic substances are present, the water damage is considered Category 3 (black).

Affected structural materials and contents should be removed.