Class 1 to 4 water damage

What it means

Class is the second label in the IICRC S500 system. Category says how dirty the water is. Class says how much drying work the job needs. Trade explanations of the standard describe four classes:

• Class 1: the least water absorbed. Wet porous materials make up less than about 5% of the floor, wall and ceiling surface area.
• Class 2: a significant amount, roughly 5% to 40% of the surfaces.
• Class 3: the most water, more than about 40% of the surfaces.
• Class 4: water deeply held or bound in low-evaporation materials, such as hardwood, plaster or brick. These need specialty drying.

Cleanfax notes the class is set after any tear-out is done.

Why it matters to your claim or your bill

Class drives equipment. More wet surface area means more air movers and dehumidifiers, and Class 4 often means specialty dehumidifiers and more days of drying. If your estimate says Class 3 for a single wet corner, ask how the restorer measured the area. A moisture meter log and photos should support the class. See our water damage restoration cost page for how equipment days add up.