After a wet disaster such as a flood or burst pipes, moisture will affect substructures such as plaster,drywall, wood, concrete and carpet. Mould is of course a primary concern, but there may be other problems related to water damage – crumbling drywall and plaster, rusting metal surfaces, weakening supports, electrical faults and more. If the moisture is not dried quickly enough you run the risk of eventually bringing the whole house to ruin. By calling in a water damage restoration company, a cleaning crew will be able to properly the situation and advise on the best plan for repair.


Category 1 is liquid from a clean and sanitary source such as taps, drinking fountains, toilet tanks etc. If category 1 damage is not dealt with quickly enough, it can degrade into category 2 or 3.

Category 2 is also known as grey water, and is characterised by having a level of contaminates that may cause illness if ingested. Sources of category 2 liquid damage include dishwashers, washing machines and flush from sink drains. Category 2 can degrade into Category 3 given such factors as time, temperature and contact with contaminates.

Category 3 is grossly unsanitary and likely to cause severe illness and possibly even death if ingested.Sources include sewer backup, flooding from rivers or streams, toilet overflow and stagnant liquid that has begun to support bacterial growth.

The next step in assessing water damage is deciding which class of destruction it is. There are four classes of destruction:

Class 1 has a low saturation rate and only part of a room or area is affected. There is little or no wet carpet and the moisture has only affected materials with a low permeance rate such as plywood.

Class 2 affects an entire room including carpeting, the wetness has wicked up the walls at least 30cm and there is moisture remaining in the structural materials.

Class 3 has a high level of destruction and involves saturation of the walls, ceilings, insulation, carpet and sub floors. The liquid may have come from overhead e.g. a leaking roof or overflowing upstairs bathtub.

Class 4 is a speciality drying situation which means there has been enough liquid and time to saturate materials with a very low permeance such as hardwood, brick and stone.

A qualified water damage technician will be able to tell the difference between these classes and categories and form a restoration plan based on those factors.