Category 1 water damage: clean water, and the clock on it

Category 1 is the least expensive category of water damage to deal with, for a limited time. The water came from a clean source, so most of what it wet can be dried rather than thrown out. The catch is that the category describes the water now, not the water when it escaped, and clean water does not stay clean in a carpet.

What counts as Category 1, and what does not

The supply-versus-discharge line is the one people miss. A washing machine’s inlet hose carries clean mains water; its drain hose carries grey water. The same appliance can give you either category depending on which hose failed. Grey water and Category 3 cover the other two.

The clock: how clean water stops being clean

A category is a description of contamination, and water picks contamination up from whatever it soaks through and sits in. The published guidance puts timeframes on wet materials:

• SafeWork NSW: clean up wet areas and water damage promptly, within 24 to 48 hours, and discard porous materials that have been wet for more than 48 hours (SafeWork NSW, Mould at work).
• Queensland: absorbent items that can’t be cleaned easily should be thrown away if they are wet for more than 2 days (Queensland Government, Mould (disasters and emergencies)).
• Better Health Channel: its advice not to store untreated greywater beyond 24 hours, because microbes thrive, is written for garden reuse, but the reason applies to standing water in a building.

So the cost of a Category 1 job is mostly a function of time. Caught the same day, it is extraction and a few days of equipment. Left over a long weekend, it can be underlay replacement, HEPA filtration and mould.

What Category 1 drying costs, and what delay adds

The third row is drying only; it leaves out the underlay, plasterboard or carpet that a delay can turn from “dry in place” into “remove”. Repair costs has the published reinstatement prices, and water extraction why the first hour matters.

What usually survives clean water depends on the material more than the volume. Carpet over a slab, caught early, can often be dried in place; underlay is the weak point because it holds water. Plasterboard that was wet briefly can be dried if the readings come back down; insulation in a wall that stayed wet cannot. Solid timber floors can sometimes be dried and sanded. Wet carpet covers the carpet decision in detail.

The decisions are made with a moisture meter, not by eye. A restorer takes readings in the carpet, the underlay, the wall bases and any subfloor on the first visit, and again each day; equipment comes off when the readings reach the dry standard for that material. Those readings are what tell you whether a wall can stay or has to be cut, and they are the record that the job was finished rather than abandoned when the surface felt dry. Ask for them in writing, every day, from the first visit.

The first hour is the cheapest one. Every litre extracted from carpet and underlay on the day is a litre the dehumidifiers do not have to pull out over the following days, and equipment is billed by the day. On a Category 1 job that is the whole difference between three days of drying and a week, and between keeping the underlay and replacing it. Dehumidifier hire compares doing the drying yourself for a small, clean, fresh leak.

Category 1 and the claim

The supply-side sources in the first table fall under this one: the escape of liquid from a fixed pipe or apparatus. The usual argument is about the failed part, which reg 19(2)(b) takes out as wear and tear, rust or corrosion, so keep it. And because Category 1 damage grows with time, the drying record from the first day is also the evidence that the damage was limited promptly. The burst pipe guide covers the claim in detail.

Common questions