Mould removal after water damage: what it involves and what it costs

Mould removal is two jobs sold as one. Taking the mould off a surface is the cheap part. Finding and drying whatever fed it is the part that decides whether you pay for it twice — because, in NSW Health’s words, mould is likely to return unless you fix the cause.

Clean it yourself, have it cleaned, or throw it out

The left-hand column is genuinely do-it-yourself: all four health departments give a household method, and the Better Health Channel’s version is that small to medium sized areas of mould may be removed at home (Better Health Channel (Vic), Mould removal at home). The right-hand column is where the money goes, and the reason is always the same: the material has held water, and either it has to be dried to a measured reading or it has to come out.

Four health departments, side by side

They agree on more than they disagree on, and the one real disagreement is bleach.

On bleach, the difference is about what it is for. NSW Health gives a dilution for a surface that will not come clean; Queensland’s flood guidance says bleach is not an effective mould killer but helps with the other organisms floodwater brings. Either way, bleach does nothing about the water that grew it. WA’s guidelines say mould is not considered a hazardous waste, and SafeWork NSW, Mould at work says mouldy items can usually be discarded as general rubbish.

SafeWork NSW’s guidance, written for workplaces, puts a clock on it: clean up water damage within 24 to 48 hours, and discard porous materials — ceiling tiles, plasterboard, insulation, carpet — that cannot readily be cleaned or have been wet for more than 48 hours. That is the same window Queensland uses for household items, and it is why the first two days after water gets in decide how much of this page applies to you.

A dash in the table means the page read for this site does not address the question, not that the department disagrees.

What professional mould removal involves

A quote that says “mould removal” and a number tells you almost nothing. The work breaks into six parts, and asking which of them a quote includes is how two quotes become comparable.

1. Find what is feeding it

A leak, a failed shower membrane, a roof, rising damp, or condensation from a room that does not ventilate. Without this step the rest is temporary, and it is the step a surface-cleaning service skips. A moisture meter finds wet material that looks dry.

2. Contain the area

Plastic sheeting over the doorways and, on larger jobs, an air filtration unit so that mould disturbed during removal is captured rather than blown through the house. On the published rate card this site reproduces, a HEPA air filtration unit is $80 per unit per day with a 3-day minimum.

3. Remove what cannot be cleaned

Porous material that is mouldy or still wet: carpet and underlay, plasterboard, and anything soft. NSW Health’s position that absorbent materials may need to be professionally cleaned or replaced is the working rule.

4. Clean what stays

Hard surfaces and structure are cleaned rather than replaced. Ask what with, and whether the product is one the company will name in writing.

5. Dry it to a reading

Drying is the part that stops it coming back, and it is measured with a meter, not judged by touch. The cost page prices the equipment.

6. Check that it stayed dry

A second set of readings after the equipment has gone. It is the document that shows the building was dry when the job was signed off, and it is the one an insurer or a landlord will ask for if the mould returns.

What mould removal costs

These are the published Australian figures this site could source. They are the mould side only.

The kitchen-or-bathroom range runs from $50 to $4,000. hipages does not say what puts a job at either end, and this site does not guess. The range is wide enough to hold both a surface clean and a job that goes into the wall, and a quote should say which one it is.

hipages also publishes state-by-state hourly rates for mould removal. They are not reproduced here, because the same publisher’s carpet cleaning hourly rate is higher than its mould removal rate, and those two figures cannot both describe the same labour market. The methodology post explains the rule: where a publisher’s own figures disagree, neither is republished.

What the table leaves out is the drying, and the drying is what decides whether the whole-home figure is spent once or twice. Two rooms dried over five days with one HEPA unit running, on the published rate card:

A quote for mould removal that has no drying line and no moisture readings on it is a quote for cleaning. That can be the right job — a bathroom ceiling with condensation mould and nothing wet behind it — but it should be a decision, not an omission.

Testing before removal

NSW Health, Mould factsheet: since most mould is visible, testing is generally not necessary. The exceptions it accepts are the ones where you cannot see the extent or cannot find the source. So an air sample test at $250–$300 on visible mould in a room you can see is worth questioning; on a smell with no visible source it can be the right first step. The mould cover page goes further into what a test does and does not settle for a claim.

Who pays for mould removal

Owner-occupiers. Mould is a consequence, not an event, so the insurance question is always about what made the building wet. A burst pipe is a listed event under reg 19(1)(a)(vi); condensation is not on the list. Whether the policy limits what it pays for mould is in its wording and its Key Facts Sheet, which the insurer must keep on its website in a downloadable format (Insurance Contracts Regulations 2017 (Cth) reg 13(4)). The mould cover page works through the causation chain.

Unit owners. In a Queensland scheme on a building format plan the body corporate must insure the building for full replacement value (Body Corporate and Community Management (Standard Module) Regulation 2020 (Qld) s 198(2)). The ACT goes further and names the risk: owners corporations must insure against bursting, leaking and overflowing of boilers, water tanks, water pipes and associated apparatus (Unit Titles (Management) Act 2011 (ACT) s 100(1)(d)). If the mould came from a pipe in the building, the building side of it is the scheme’s claim.

Tenants. Victoria’s law names mould directly. Every room must be free from mould and damp caused by or related to the building structure (Residential Tenancies Regulations 2021 (Vic) sch 4 item 8), and the presence of mould or damp caused by or related to the building structure is an urgent repair (Residential Tenancies Act 1997 (Vic) s 3(1), definition of urgent repairs, para (k)(ii)). In New South Wales, who is responsible depends on how the mould developed (NSW Fair Trading, Mould in a rental property): the landlord, where it came from a repair not made in reasonable time or from inadequate ventilation; possibly the tenant, where the tenant let moisture build up by never ventilating. Fault or damage that makes the property unsafe and causes health risks such as mould may be an urgent repair. HealthyWA says mould and damp caused by structural faults or leaks should be remedied by the owner. In the ACT, the urgent repairs list read for this site does not name mould, but a burst water service and a serious roof leak are urgent repairs (Residential Tenancies Act 1997 (ACT) sch 1, cl 60), and mould that grows because one was not made is a consequence of that repair.

Is mould removal regulated?

This site found no licence to check in the way there is for a builder or a plumber, and two public documents explain why.

So the checks available to you are practical ones. Ask what the company will do about the moisture source; ask for moisture readings before and after; ask what is being removed and what is being cleaned; and ask whether drying is in the price. Answers to those four in writing are something you can check afterwards.

Common questions