How to remove mould and prevent it coming back in your home

What is mould?

Mould is a type of fungus that grows and spreads on damp, poorly ventilated areas. Although mould originates from plant and animal matter, its reproductive spores become airborne and can float indoors. “Mould spores thrive on damp, moist or warm surfaces,” Davies says.

While "black mould" is often associated with toxic health risks, the colour of mould isn't an indicator of its danger. "Black mould" can refer to several species of mould that are dark green or black, such as Stachybotrys chartarum.

The more common types of mould to appear in the home are:

• Alternaria – occurs in damp indoor spaces, such as in showers or under leaky sinks
  

• Aspergillus – often grows indoors on dust, powdery food items, and building materials like drywall

• Cladosporium – can grow in cool or warm areas, tending to appear on fabrics and wood surfaces

• Penicillium – tends to grow on materials with water damage; usually blue or green in appearance.

Mould is a type of fungus. Image: Getty

What does mould look like?

“Mould can look quite different depending on where it grows, as well as the type of mould it is,” says Davies. “Keep an eye out for white, black, yellow, blue, or green spots that look like a stain on the surface.” Rarer moulds can appear grey, orange or brown.

How to stop mould in your home

The best way to reduce mould in the home is to minimise moisture in all areas, according to Davies. “Since poor ventilation is one of the main causes of mould, the best thing to do is to ensure you have as much ventilation as possible throughout the home, under the floors, and in the roof.”

A dehumidifier can potentially stop mould forming by absorbing excess moisture from the air. A dehumidifier also helps improve air circulation and quality, and reduces allergens like dust. In addition, air purifiers can filter mould spores out of the air, effectively stopping reproduction – but that won't stop active mould growing on surfaces.

How can I effectively remove and kill mould? Does bleach work?

Bleach does not kill mould – it just removes the colour from the mould, so it’s invisible to the naked eye. Instead, use a mix of baking soda and white vinegar or a methylated spirits solution to kill your mould. Both these ingredients destroy the microscopic structure of the mould, immediately killing it.

Do a spot test on any surface before cleaning. Vinegar is highly acidic and can damage surfaces such as grout over time. Methylated spirits is generally safe to use on hard surfaces like grout, glass, stone, ceramic, marble, chrome, et cetera – plus they are biodegradable and eco-friendly.

After you've wiped a surface, rinse the dirty cloth regularly in a separate container of clean water to stop the mould spreading. Avoid scrubbing with a dry brush as this can flick spores into the air.

Natural ingredients like white vinegar and baking soda can help get rid of mould. Image: Matt Harvey

How to remove and prevent mould in the bathroom

There is an easy home remedy that you can use to remove mould from your bathroom walls, ceilings, and floors. Simply mix one part undiluted white vinegar with two parts baking soda in a spray bottle. Spray the mouldy areas with this solution. Leave the treated area for a few hours. Use a damp cloth to scrub and wipe off the mould, then rinse with water. 

Proper waterproofing can help prevent mould in the bathroom. “It’s essential that all bathrooms are correctly waterproofed and that the roof is weathertight,” Davies says.

Grout mould – the kind that blackens the white lines between your bathroom tiles – is particularly prevalent in domestic bathrooms. To help prevent grout mould, you can:

• Regularly clean your bathroom with safe antifungal solutions that also get rid of soap scum (soap residue that allows mould to thrive).
• Keep the shower door, bathroom door and any bathroom windows open after showering to air out the space.
• Install an exhaust fan and leave it on during your shower and for about 20 minutes afterwards.
• Reseal the grout once or twice a year after a thorough clean and dry.

“Fixing leaking plumbing and ensuring all surfaces are dried after showering or using the bath can also make a difference,” says Davies.

To prevent mould growing on your bathmat and towels, choose materials that are easily washable and regularly launder them. Keep fabrics dry between showers by hanging them up properly. Likewise, dry your shower curtain between showers and regularly wash it.

Use a sponge to scrub off mould residue after spraying with a white vinegar solution. Image: Getty

How to remove and prevent mould in the wardrobe

If you find mouldy spots on your clothes, it's an indication that there's dampness or moisture in your wardrobe. To remove mould from the walls, shelving and drawers in your wardrobe, try using the white vinegar solution.

Start by removing your clothes and other items from your wardrobe. Spray the entire wardrobe. Allow the solution to soak in for about half an hour, then use a damp cloth to scrub the affected areas. Thoroughly vacuum and clean the floor as well because mould can grow there too. Ensure the wardrobe is completely dry before putting your clothes back. You can do this by leaving a fan running or opening the bedroom windows for a few hours.

To help prevent mould growing again, ensure your clothes are completely dry before putting them away. “When damp clothing meets cold internal surfaces like the ceiling or walls of the wardrobe, tiny water droplets will collect on the cold surfaces as the air cools, causing patches of mould to grow,” Davies says.

Avoid jamming your clothes in the closet and allow some airflow from your bedroom. This will also help prevent moisture. A dehumidifier may be helpful as well.

How to remove mould from your clothes or other fabrics

If you have mould on your clothes or other fabrics, mix two parts baking soda to one part  white vinegar and add this solution to a bucket of hot water. Leave to soak for about an hour or longer, depending on how much mould is present. Use a toothbrush or a brush with firm bristles to scrub the mouldy areas, then wash your clothes using your washing machine's regular cycle.

How to remove and prevent mould in the bedroom

If there is mould on the walls, ceilings or hardwood floors in your bedroom, try using a mild detergent like sugar soap and a microfibre cloth. Dry the cleaned area thoroughly after wiping mould off the surfaces. If this doesn't work, mix one cup of vinegar and one cup of warm water into a spray bottle and spray the area. Leave for a few hours, then wipe off. Allow fresh air to circulate through the bedroom for a few hours to make sure the walls and floors are completely dry after cleaning.

If you have carpet or rugs, vacuum them first, then use a carpet cleaning solution as directed on the container, or try steam cleaning the carpet.

Much like the wardrobe, the best way to stop mould in the bedroom is to prevent dampness. Leaving wet objects (like raincoats or umbrellas) on chairs, beds or carpets creates moist surfaces that can lead to mould spots. Opening bedroom windows (and/or balcony doors if you have them) is another simple action that promotes air flow and dries up dampness. 

“Fresh air is a great and cheap way to get ventilation through the home,” Davies says. “It can be unpleasant during the depths of winter, but opening doors and windows for even an hour a day can dry up a lot of moisture.”

Ensuring heating and cooling systems are regularly maintained is another way to reduce mould in bedrooms. That’s because air conditioner and heater filters can become clogged with dust, bacteria and mould over time. When you switch on a dirty air conditioner, it could pump contaminated air and mould spores into the room. RACV Trades can service your heater or air conditioner.

Chelsea Smith from The Organising Platform demonstrates how to make eco-friendly cleaning sprays and scrubs using natural, everyday ingredients.

How to stop and prevent mould in the laundry

Mould is common in the laundry because of the humidity caused by washing machines and dryers. The type of dryer you have can have an impact on moisture levels. Heat pump dryers are better than condenser dryers. Heat pump dryers do not blow hot, moist air into the room, but rather extract the moisture from wet clothes and collect in a container, which you then empty. Condenser dryers, on the other hand, produce a lot of high-heat air that needs to be properly ventilated to prevent mould.

Turning on any exhaust fans when the dryer is in use can help funnel the resulting hot, moist air out of the room. If you have a European-style laundry (washer/dryer tucked behind doors in a cupboard-like space), keeping the doors open while the dryer is running can also help.

A dehumidifier is another way to reduce moisture in the air in the laundry.

How to stop and prevent mould on windows

A great way to prevent mould on windows is to dry off any condensation. “On cold mornings, give the windows a wipe with a soft, clean cloth to remove excess moisture,” says Davies. “It’s also a good idea to open the windows and allow airflow, which naturally removes dampness from the air.”

Cleaning your windows with vinegar is another way to kill mould living on glass surfaces. You can make your own cleaner by distilling white vinegar into a spray bottle and spraying directly onto the surface, then wiping clean with a microfibre cloth.

How to stop mould growing on house foundations

Completing jobs around the house like cleaning gutters, fixing leaky pipes and maintaining roofs can have a big impact on whether water drains properly or whether it accumulates and causes dampness, leading to mould.

Leaking pipes is a leading cause of what is commonly known as rising damp. Saturated soil beneath your house can force stone, brick and mortar in your foundation and subflooring to soak up the water and start growing mould. Get leaky pipes professionally fixed as soon as possible to mitigate the risk of rising damp.

If you undertake any DIY work, always take care working at height on a ladder and use safety equipment such as gloves and non-slip shoes. Seek professional help for any job beyond your level of skill.

How do I stop mould as a renter?

Landlords are required to provide a property that is free from mould and damp. If mould forms during your tenancy because of a property defect – such as the property not having adequate ventilation or the building having structural damage that causes rising damp – then it is the landlord’s responsibility to remedy the situation. In addition, if mould forms soon after your tenancy begins, it could be considered a pre-existing problem.

On the other hand, you may be liable for mould removal costs if you didn’t take reasonable steps to prevent mould during  your tenancy. Fortunately, you can follow most of the above advice for preventing mould, such as wiping down condensation-heavy windows with a microfibre cloth, turning on the bathroom exhaust during and after showering, and regularly cleaning bathroom tiles.

If you notice mould forming, contact your landlord or real estate agent for advice and document all correspondence on the matter.

Cleaning your gutters regularly helps to prevent moisture build up which can cause mould. 

How to deal with mould after flooding

Floods and storms can result in pooled water sitting in and around your house for extended periods of time. This creates perfect conditions for mould to grow. The Victorian Department of Health reports that high mould levels are likely if a house is flooded for more than two days.

If you return home after a flood and notice water damage, visible mould or a strong musty smell, quickly clean up and dry out your home to minimise mould. Ask your insurance company to advise you on their mould policy before you start, to make sure you don’t void any coverage you’re entitled to, and take photos, videos and notes before you start the clean-up.

You can help minimise mould after flooding by:

• Opening all doors and windows to naturally air out the house

• Removing any pooled water from inside and around the house

• Moving any wet or flood-damaged items (especially soft or absorbent materials like carpet, rugs, mattresses, bedding, clothing, wallpaper, and other objects that can’t be properly cleaned, sanitised and dried) in a shed or garage until your home insurance claim is processed

• Removing wet plasterboard and insulation to allow your internal wall spaces to properly dry out

• Cleaning, disinfecting and drying hard surfaces like floors, walls, benchtops, ceilings and wall studs

• Using fans and dehumidifiers to completely dry out the house once safe power returns to the area.

It's recommended to hire professional cleaners rather than tackle mould-affected areas yourself if you have a weakened immune system, allergies, lung disease or severe asthma. If you’re cleaning up after flood damage, wear protective gear like rubber gumboots, rubber gloves, shower cap, protective overalls, and a P1 or P2 mask.

If you are not affected by flooding, consider donating to people affected by storms and flooding via a reputable charity like GIVIT. Find out other ways to help and give support after a natural disaster here.

Mould and your health

Breathing in mould spores and fragments can trigger nasal congestion, sneezing, coughing or wheezing, and respiratory infections, according to the Victorian Department of Health. Mould can also worsen asthma and allergic conditions, and irritate eyes and skin.

People with weakened immune systems, allergies, severe asthma or lung diseases are more susceptible to experiencing these symptoms.

If you’re concerned about mould and your health, you can seek medical advice and contact your local council.