Why the category matters
Water from the tank or the supply line is clean, Category 1, and a bathroom soaked by it can usually be dried. Water that came over the rim from the bowl is at least Category 2, and if it carried waste it is Category 3. Porous materials touched by Category 3 water, like carpet, pad and the drywall at the base of the wall, get removed, not dried.
- A stuck fill valve overflowing the tank: usually Category 1
- A clogged bowl overflowing: Category 2 or 3
- Several fixtures backing up at once: a main line problem, Category 3
- A failed supply line or wax ring: water under the floor and in the ceiling below
If more than one drain is backing up, the job is really a sewage backup.
How a bathroom gets cleaned and dried
The extraction crew removes the water and, for contaminated water, the mitigation team wears PPE and removes contaminated porous materials. Hard surfaces are cleaned and treated with an EPA-registered antimicrobial. The tech who does the walkthrough checks under the vinyl or tile, behind the vanity and in the ceiling below, because a wax ring leak or overflow often soaks the subfloor where it cannot be seen.
In Antioch townhomes and stacked apartments, the bathroom often sits over a kitchen or living room, so the ceiling below is part of the job. The drying team runs air movers and LGR dehumidifiers and logs readings until the goal is met.
Health notes
The EPA indoor air quality pages explain why contamination and moisture indoors matter for health. The EPA mold page covers why wet subfloor and drywall need drying quickly.
