How To Clean Mould & Stop It Coming Back (Like A Professional)

Mould is often dangerous to our health, it's difficult to remove and oh man it's ugly. But most of all, it's really frustrating when it keeps comes back. In this article, we explore how you can clean mould like a professional and how to stop mould from coming back.
10 January, 2023 by
How To Clean Mould & Stop It Coming Back (Like A Professional)
XO2® Pty Ltd, David Blamire

Mould is often dangerous to our health, it's difficult to remove and oh man, it's ugly. But most of all, it's really frustrating when it keeps coming back.

In this article, we explore how you can clean mould like a professional and how to stop mould from coming back.

How do we know about mould? Why listen to us?

XO2 is Australia's leading manufacturer of mould cleaning and treatment products for professionals and facilities. We know the drill, and we've been doing it for over 50 years.

Whether you're a mould restoration professional or a mould-hating weekend DIY warrior, get the tips, tricks and products you'll need to win this battle right here.

How to clean and kill mould for good:

- Remove the moisture
- Clean the mould
- Treat the spaces
- Improve ventilation

😷 Step 1. Wear PPE (Personal Protective Equipment)

When cleaning and treating mould always wear PPE including nitrile gloves, goggles, respirator, sealed footwear and coveralls. Mould can be very dangerous. Do not skip this step and don't come into direct contact with it.

💧 Step 2. Begin the ventilation and drying process.

a. Remove mould-damaged items.
b. Get some dehumidifiers going.

c. Turn your air conditioner system on.
Most air conditioning systems have a mode specifically for this. It is generally "DRY" or a little picture of a water droplet💧. Or ventilate the area by opening windows if it's dry outside. There are more tips further down in this article.

🧽 Step 3. Clean the mould-affected surfaces and surrounding areas

(we'll deal with moisture problems and air quality in step 4)

Everyone has an opinion on what works best for cleaning mould... iDestroy, 30 Seconds, White Vinegar, Morning Fresh, Wonder Gel, Bobby Dazzler, Bleach, Clove Essential Oil and the list goes on.

If you want homebrew advice from a random person on Facebook, this isn't for you. If you want solutions that use HARD SCIENCE for professional mould cleaning, read on...let's do this.

👍 Pro Tip

However, if you choose to clean mould, work carefully and methodically. Using too vigorous a cleaning method or trying to clean too quickly can disturb the mould spores helping the mould to spread further.

What's wrong with cleaning vinegar on mould? (We manufacture cleaning vinegar, so we should know)

So-called experts and some government departments love recommending white cleaning vinegar diluted 3:1, 4:1 or 5:1 for mould removal. XO2 manufactures cleaning vinegar, and while it's technically better than using nothing, we don't recommend it for professional mould or flood clean-ups. According to research and the advice of our microbiologists, vinegar has NOT been sufficiently substantiated as being effective against mould. It is not recognised by the TGA for this type of application. In humid conditions, the water component of a vinegar solution could even further worsen a moisture problem. Keep in mind that vinegar does not function as a surfactant (bleach doesn't either) which means it will not help by itself with the physical removal of fungal material from surfaces.

What about chemical-free and non-toxic mould removal products?

We all want to avoid using hazardous and dangerous chemicals but be careful of chemical-free product claims. Remember water is a chemical (H2O). So when you see chemical-free claims keep in mind it is more marketing than truth. In most cases what "chemical-free mould cleaner" means is the chemical is classified as non-hazardous which is not a very high standard.

It's also important to consider the consequences of an ineffective mould treatment. It's absolutely critical you get your mould removal system right for the health and safety of you and those who enter the places and spaces you are responsible for. Mould removal isn't a ''near enough is good enough'' procedure.

👍 Pro Tip

Just because a product safety data sheet recommends the use of gloves and other PPE it doesn't necessarily mean the product is toxic or hazardous. Always use PPE for mould removal even if you're just using a chux style cleaning cloth with no chemicals.

What's wrong with using Bleach for cleaning mould?

Bleach, Chlorine and Sodium Hypochlorite are the same chemical at different concentrations. Bleach is a great destainer,  sanitiser and disinfectant but a very poor cleaner and it does very little to remove mould away. It does bleach the mould giving the illusion that the surface no longer has mould on it.

We do not recommend using Bleach only or chlorine ONLY products, even though the surface may look clean after use. Our preference for effectiveness, speed and cost is a combination of heavy-duty cleaner with bleach. This can be the best of both worlds... 1. cleaning the mould away with its roots and 2. quickly making the surface look new again. A cleaner with bleach may permanently damage some carpets, curtains and soft furnishings so keep that in mind.

#1 recommendation for cleaning indoor and outdoor mould... 

iDestroy (4-in-1 product)

There are 4 parts to iDestroy Mould Remover & Preventative Treatment...
1. It contains Sodium Hydroxide... So it really cleans.
2. It contains Bleach... So it destains and makes the ugly mould disappear.
3. The bleach also sanitises and disinfects the surface, boosting overall mould treatment performance.
4. The best part... it contains a Proprietary Blend of high-technology ingredients (our secret non-hazardous sauce!)... that improves fungal removal and helps to prevent new growth depending on conditions such as traffic, rainfall, humidity and foliage cover.

iDestroy is not a surface coating. However, when you apply and leave the product, it kills the mould, removes the mould and leaves a residual to help stop it from coming back. It comes ready to use (no mixing required) and does not require rinsing or scrubbing. iDestroy does contain some Bleach so it does have a bleach smell. While washing down a surface is sometimes required, rinsing and scrubbing can use unnecessary amounts of water. This additional water use can also create more moisture problems and when it goes down the drain it isn't good for septic systems. Be mindful when cleaning indoors that you do so in a way that will limit the spread of airborne mould spores.

👍 Pro Tip

Use XO2 iDestroy even on the most difficult outdoor mould-covered areas like tennis courts, retaining walls, pathways and driveways for fast and long-lasting results. 

What about soft furnishings?

Carpets, curtains and upholstery that are damaged by mould are usually best thrown away. If you decide to try and clean these do not use a bleach-based product. In most cases, peroxide-based products like XO2 Wizz King are fine to use but always test first of course.

#1 recommendation for an after-cleaning antimicrobial treatment... 

Disso (hospital grade)

After cleaning with iDestroy mould remover and preventative treatment, when the surfaces are dry, an XO2 Disso antimicrobial treatment can be applied to surfaces and spaces via an electrostatic fogger.

What causes mould to come back? (Hint: Moisture and mould spores)

In a nutshell, moisture and the tiny mould spores that love moisture are our enemies. Mould spores are the reproductive particle of moulds. Whether it's indoors or outdoors, mould spores are always there floating around. They can't be 100% eliminated, but they can be reduced to manageable levels.

How to stop mould coming back (2 critical steps after cleaning)

After effectively cleaning the mould from the surface there are 2 critical steps that need to be taken to ensure mould doesn't come back. These 2 steps are what sets a professional mould treatment process apart.

1. Use an effective antimicrobial treatment like Disso throughout spaces after cleaning.
2. Eliminate any moisture problems.

Step 4. Eliminate Moisture & Humidity Issues.

If you don't treat the moisture problem mould will be back. Even on clean dry surfaces, mould will return if there is enough moisture or humidity. But how can this be done?

I hear you...
"We can't do anything about the rain, it hasn't stopped"
"I can't hold back the floodwaters"

Don't give up! We're about to get to the good part. Even though we can't stop the rain, flooding or the high humidity, we can still stop or at the very least drastically reduce mould.

🦠 Control moisture outside even if the mould is only inside

For those of you who only have mould issues inside, it's important that you also read the tips below for outdoor areas. Your outdoor environment affects indoor moisture levels. If you have a heavy load of mould spores outside it's much more difficult to control mould inside.

🦠 The mould-stopping, moisture-eliminating checklist...

Tick off as many as you can and you'll be on your way.

A. Indoor Checklist
Reduce air moisture levels
  • Use a dehumidifier (#1 Tip)

  • Run your air conditioner: most air conditioners have a dry/low humidity mode.

  • When you're not running your air conditioner, open up your doors and windows (not on wet or cold days though.)

  • Use your fireplace regularly if you have one.

Stop the wet
  • Fix leaks (make sure you check roof spaces too.)

  • Discard unused water from baths, sinks etc.

  • Some wallpapers can tend to be mould prone. Think about replacing it.

  • Dry your clothes outside if possible (unless you have a dehumidifier.)

  • Keep wet and muddy boots and shoes outside.

Improve ventilation
  • Always use an extractor fan when showering. Consider upgrading your bathroom ventilation if required.

  • Run your kitchen exhaust fan when cooking or boiling the kettle.

  • Keep lids on pans when you cook.

  • Prevent condensation with more ventilation or insulation.

  • Ensure beds and other furniture are positioned away from and not too close to walls to allow for adequate ventilation.

  • Vent the exhaust air outside from your laundry dryer or consider upgrading to a heat pump dryer (keep in mind that heat pump dryers are usually too heavy to wall mount).

  • Open curtains and blinds during the day.


Just using fans or air movers can actually help spread mould spores.

2. Outdoor Checklist
  • Fix broken roof tiles.

  • Clean gutters.

  • Paint the roof if it's porous, holding moisture and mouldy in places.

  • Repaint any timber where paint has cracked, peeled or become porous with age.

  • Seal outdoor floor surfaces that are porous and hold moisture like paths, driveways and entertaining areas. This includes oiling your outdoor timber decks.

  • Remove gardens that are against or close to the house. This is a good termite prevention technique too.

  • Ensure downpipes and stormwater drainage are working and not blocked.

  • Install garden and yard drainage so water does not pool or puddle anywhere close to your house.

  • Throw away mould-damaged items.

  • Keep piles of garden mulch and compost away from the house.

  • Cut branches and remove trees that cast excessive shade over the house. This also improves airflow. The more natural sunlight the better.

  • Don't buy a house that is mostly in the shade through the rainy and colder months.

  • Installing air vents under eaves can be helpful for roofs with mould and moisture problems.

If you liked this article and have decided to take action, all the very best. Stopping mould can be a challenge but it's worth it. If you need us, the team at XO2 is ready to help.

Have a great day! 

David Blamire, CEO at XO2

David is one of Australia's leading cleaning industry innovators. He's spent his entire working life solving cleaning challenges others thought were impossible. He's best known for his product creation and development skills along with a deep knowledge of business operations and all things ERP. In his spare time, David's a keen fisherman and adventurer. And he doesn't mind if you call him Davo.

Get in touch with David at He works from XO2's national headquarters and manufacturing centre in Queensland, Australia.

Related articles:

Carpet Drying And Clean Up With The Express Method
How To Do Flood Clean Ups (Including Mould Removal & Surface Decontamination)
3 Crucial Clean Up Steps That Need To Be Done After A Flood Disaster
10 Rules You Can't Break When Using An Air Mover & Carpet Blower Or Someone Might Get Hurt

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