Water Damage Categories and Classes Explained
· 5 min read · Water Damage
Clean, gray, and black water — plus the four drying classes — explained in plain English for homeowners.
Category 1: Clean water
From supply lines or faucets. Low risk if addressed quickly, but it can degrade into Category 2 within 48 hours.
Category 2: Gray water
From washing machines, dishwashers, or toilet overflow without waste. Contains contaminants that can cause illness.
Category 3: Black water
Sewage, flood water, or long-standing water. Requires protective equipment and removal of affected porous materials.
Classes 1–4
Classes describe how much water and how hard it is to dry — from a small area (Class 1) to dense materials like hardwood and concrete (Class 4). This guides equipment placement.