Mould turns up in the same places every time. The bottom corner of the shower screen. The ceiling above the bath. The back wall of a wardrobe that nobody has opened since autumn. If you have lived through a wet Queensland summer, you have probably had to deal with mould across the entire home.
And mould is not really a cleaning problem. It is actually a moisture problem that shows up as a cleaning problem. You can scrub a wall back to white on Saturday and watch the same patch come back a fortnight later, because whatever was feeding it never went anywhere.
So this guide covers how to remove mould safely, what to clean it with, and how to make the work last.
Before You Start
Open the windows and doors before you do anything else, and put on protective gear. A shower cap, rubber gloves, eye protection, overalls, suitable footwear and a P1 or P2 face mask are ideal, and you can typically pick up from any hardware store.
Some people should not do this job, or be in the room while it happens. That includes pregnant women, children, and anyone with a weakened immune system or a chronic lung condition such as chronic obstructive pulmonary disease. If you are allergic or sensitive to mould, you may notice a stuffy nose, irritated eyes, wheezing or skin irritation.
Two things worth knowing before you touch anything:
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Do not dry brush mould. A dry brush flicks spores into the air, where you will breathe them in, and spreads the problem to rooms that were fine. If you vacuum a mould-affected area, use a HEPA-filtered vacuum. Anything else puts the spores straight back into the room.
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Do not mix cleaning products. Bleach mixed with ammonia, acids or other cleaners can release chlorine or chloramine fumes. This is the one rule every state health department agrees on without qualification.
Step 1: Find The Moisture And Fix It
Mould only grows in damp, unventilated spaces. Remove the damp, and you remove the reason it came.
Start with the obvious water. Check the roof, gutters, and plumbing, including pipes and drains that might be quietly leaking behind a cabinet. If something needs repairing, get a plumber in before you start cleaning.
Then look at the less obvious sources, such as condensation from showering, a clothes dryer venting into the room, unflued gas or kerosene heaters, fish tanks, and thirsty indoor plants like ferns. The Queensland Government also points out that plants and bushes growing hard against an external wall hold moisture in, so clearing them back helps more than you would think.
If you clean without doing this, you are booking yourself a repeat job.
Step 2: Choose What You Clean With
For most household mould, you do not need anything exotic. Household detergent or white vinegar will be enough in many cases. NSW Health puts a number on the vinegar: 4 parts vinegar to 1 part water for routine clean-up of mouldy surfaces. On painted surfaces, dilute it further, closer to half and half, so you do not damage the paint.
Use a microfibre cloth, and rinse it regularly in a separate container of clean water. Rinsing a dirty cloth in your cleaning solution just moves the mould around the room.
Where Bleach Sits
The Queensland Government advises against bleach on the basis that it is not an effective mould killer, though it notes that bleach does help eliminate other disease-causing organisms after contaminated floodwater. NSW Health takes a different line and lists a diluted bleach solution, 250ml of bleach in 4 litres of water, as an option where mould is not readily removed, and the item cannot be thrown out.
What everyone agrees on is that bleach should never be mixed with other cleaners and that, on porous surfaces, its effectiveness is questionable. If a wall goes white and the mould returns to the same spot, that is the reason.
Purpose-Made Mould Products
Products made for the job are the third option. Check how much to use, check which surfaces it is rated for, and follow the safety instructions. Apply it and give it time to work before you wipe or sponge it away. Avoid soaking the area, and dry it afterwards.
If you would rather not deal with bleach fumes in a small bathroom, our Mould Power is the bleach-free option in our range, made here in Queensland and rated for tiles, grout, shower screens, painted walls and fabrics. As with any product, follow the directions on the label rather than ours.
Step 3: Work Through The Surfaces
Bathroom And Shower
Grout lines, silicone seals, and the runners at the base of a shower screen are where bathroom mould lives because they stay wet the longest. Work the cleaner into the grout with a brush rather than a cloth, and give it the contact time the label asks for. Silicone is porous and holds mould in a way tile does not, so if a seal has gone black through to its depth and will not come back, replacing the silicone is the fix. No cleaner reaches what is underneath.
Walls And Painted Surfaces
Dilute your vinegar for paint. Work in small sections, top to bottom, and keep rinsing the cloth. If the paint is bubbling or the plasterboard behind it feels soft, stop cleaning and find out where the water is coming from, because you have a building problem rather than a cleaning one.
Ceilings And Cornices
Ceilings can be awkward to clean because everything drips back at you, which is why eye protection is required. Work in sections, keep a dry cloth in your other hand, and take breaks so you are not standing under it any longer than you need to. Mould above a shower or bath is almost always a ventilation story, so make a note to come back to the exhaust fan.
Fabrics, Clothing, and Soft Furnishings
Clothing, bedding, towels and soft toys can go through the washing machine on a hot cycle. Wash whatever you wore while cleaning separately from everything else. Items that have been mouldy for weeks, bedding in particular, may not come back.
Soft furnishings that cannot go in a machine need professional cleaning. If that is not practical, they need to go.
What Does Not Come Back
Some things are not worth the effort. Cardboard boxes and mattresses should be thrown out. Absorbent materials like carpet, especially anything with a jute backing, may need professional cleaning or replacing.
Step 4: Dry The Area Properly
The simplest method is to open the doors and windows and air the house thoroughly. If the weather is against you, WorkSafe Queensland suggests fans, wet vacuums, dehumidifiers, heaters, or running the air conditioner on dry mode. Whatever you use, the surface needs to be completely dry to ensure the mould won’t come back.
Keeping Mould From Coming Back
Once the area is clean and dry, a few small habits will help keep it that way:
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Run the exhaust fan while you shower and for a while afterwards, not just during. If your bathroom has no fan, leave the window open and the door ajar
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Vent the clothes dryer outside, and dry washing outdoors when you can
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Open up the house on dry days. Airflow costs nothing
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Leave wardrobe and cupboard doors open now and then, and avoid packing them so tightly that air cannot move
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Choose low-water plants like succulents for indoors over moisture-loving ferns
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Deal with the mould the week you notice it
When To Call Someone In
Some jobs are bigger than a spray bottle, and there is no sense pretending otherwise.
If large areas of mould keep regrowing after you have cleaned them properly, a mould remediation professional may need to be considered. The same applies if you can smell mould but cannot find it, or if you have fixed the moisture, done the cleaning, and it keeps coming back anyway. In those cases, an occupational hygienist or an environmental health professional can find what you cannot see, including mould in wall cavities or ceiling spaces.
Before you pay anyone, though, ring the environmental health section of your local council. They give advice on this for free, and they know the housing stock in your area.
Try OzKleen’s Mould Power
Dealing with mould around the house can be extremely frustrating, particularly in stubborn bathroom corners. OzKleen’s Mould Power has been a household staple for decades, offering a powerful alternative to many bleach-based sprays on the market.
Not only is it non-toxic, chlorine-free, and fume-free, but it’s also biodegradable and asthma-friendly, making it a smart choice for homes that care about health and the environment.
Looking for the best mould remover solution? Try OzKleen Mould Power today and see the difference for yourself.