How to clean mould and avoid serious health risks

Rose Mary Petrass

Mould clean

After all the rainfall, humidity, and recent floods, an uninvited guest is starting to rear its ugly head: mould.

Mould is a serious health hazard. After a flood or heavy rains, killing it can be difficult. 

Experts are warning people to take care when cleaning up after a flood. Even though you may not be able to see it, mould spores can be everywhere. 

But dealing with mould is not a simple quick fix, especially after a flooding event. Mould goes in deep, especially in porous materials like home insulation. Be prepared for a lot of elbow grease, and you may have to rip out and replace some parts of your home rather than simply cleaning it. 

But first a bit about the hidden health risk of mould

The most common moulds can be found in carpets, wallpaper, drywall and wood. They go by the names trichoderma, alternaria, stachybotrys chartarum, the list goes on…

But all mould is a serious hazard that can present health risks that manifest in a range of ways, from cold-like symptoms, to asthma and lung infections. 

Mould can blacken and discolour your home, but more than just the aesthetic damage is its ability to rot and destroy damp wood and drywall.

But all mould is a serious hazard that can present health risks that manifest in a range of ways, from cold-like symptoms, to asthma and lung infections. 

Mould is among both the direct and indirect health effects on flood-affected communities, Dr Beau Frigault, Queensland chair of Doctors for the Environment, told The Green List

“The frequency and severity of these storms are an element of the effect of climate change. Unless climate change is addressed, they will worsen, and we will continue to see its effects on people’s health.

Mould

“The direct effects [of floods] are immediate – injury, falls, drowning, landslides, carbon monoxide poisoning, being cut off from direct access from health services and not able to reach urgent care. Indirectly, the effects come from the flood waters, especially when they don’t subside for a period, they become a breeding ground for diseases.” 

He lists diseases including mosquito-borne, gastrointestinal, infection of cuts and abrasions during community reparations, mental health impacts, and melioidosis – that was well-documented during the Townsville floods. 

And our sneaky uninvited guest. 

“It might be a number of weeks until these things present themselves. But when you have prolonged damp wet conditions, mould and fungus will thrive.” 

The health impact

When reproducing, mould releases spores, which once inhaled can make you unwell and lead to inflammation in the lung tissue. People with respiratory conditions like asthma may need to be hospitalised, but even relatively healthy people with no pre-existing conditions may have respiratory attacks. 

When reproducing, mould releases spores, which once inhaled can make you unwell and lead to inflammation in the lung tissue. People with respiratory conditions like asthma may need to be hospitalised, but even relatively healthy people with no pre-existing conditions may have respiratory attacks. 

“These are the wide health effects of flooding that most people don’t think about.”

Mould happens in the immediate phase, he said, and is prolonged if it’s not cleaned away. 

Immediately after a wet period where water gets inside the home, occupants may have potentially been exposed already. In the days following, they may develop more severe symptoms and present themselves to the emergency room. 

But it may be difficult for medical professionals to look at the symptoms and point directly at mould as the exact cause.

The only way to not be affected by the mould is to clean and remove it, and to create an environment so it doesn’t return.” 

Dr Beau Frigault, Queensland chair of Doctors for the Environment

“The only way to not be affected by the mould is to clean and remove it, and to create an environment so it doesn’t return,” said Dr Frigault. 

So how can we clean up mould safely? 

The most important thing to keep in mind is that mould itself presents a health risk, and if the mould is a result of flooding, flood waters may carry contaminants and diseases. 

  • Always wear a respirator mask when dealing with mould. The best mask for cleaning mould is an N95 respirator
  • Always wear proper protective gear. This includes gumboots, eye protection and gloves. Wear old clothes that you’re prepared to throw away after cleaning – long pants and long sleeves
  • Areas with water damage such as walls may have hidden hazards, including unsafe electrical cables. Never cut into a wall without first locating the electrical cables and turning off the power to the home beforehand. Never touch any electricals that may have been exposed to water, unless all the power is turned off first. Always have an electrician assess the area before cleaning, and never touch fallen or damaged power lines
  • Don’t let kids assist with cleanup, as there is too much danger involved. Keep kids and pets out of the area until completion 

How to know what to treat for mould and what to replace?

Cleaning up mould can be a costly undertaking. Some surfaces are better off ripping out and replacing rather than trying to clean. Be prepared to throw away some of this equipment after use, because mould spores are very difficult to clean off.

cleaning window
  • Proper ventilation can help clear away humidity and dampness. Open windows, turn on fans, and purchase dehumidifiers to reduce moisture content in the air. It’s recommended to set fans to blow out the window to ventilate the room while cleaning
  • Reduce spread in the house as much as possible. Turn off airconditioning or heating and cover ducts with plastic and tape to keep spores contained within the contaminated area. Seal off the area from the rest of the house by closing the doors and covering the doorway with overlapping plastic sheeting taped to the wall and floor
  • To control airborne spores, spray mould with water using a garden pump sprayer while you work
  • Soft furnishings affected, like water damaged couches and clothing, will need to be disposed of 
  • Affected carpets will need to be ripped up, the area treated with mould cleaning solution and replaced 
  • Walls may be hiding mould growth inside wall cavities and insulation that will need to be replaced and the area treated with mould cleaning solution. Remove baseboards, drywall and trim, open up stained or swollen walls 
  • Again, make sure you turn off the power and locate electrical wires in the walls before cutting. Seek the help of an electrician 
  • If removal is difficult or impossible, treat affected areas with a wood preservative after cleaning the wood and allowing it to dry. Treated the area with a mould cleaning solution. Then double up rotted members with treated wood
  • Double-bag mould-infested debris in garbage bags for immediate disposal. Vacuum up any leftover debris 
  • Thoroughly clean out vacuum and other equipment used, using a mould cleaning solution  

What type of treatment should be used to kill mould?

The simplest way to get rid of mould is through exposure to direct sunlight and fresh air, and cleaning with hot soapy water. If that isn’t possible, you will need to treat with a mould cleaning solution. 

Most commercial mould cleaning solutions contain bleach to kill mould spores and remove mould and mildew from the surface of materials. But bleach is only effective on non-porous surfaces and materials – it cannot penetrate to destroy the growth at its roots. Also, bleach fumes are dangerous to both humans and pets. 

  • Vinegar is more effective for removing mould from porous materials. This is because vinegar will penetrate porous materials and kill the growth at the roots. Note: never mix bleach and vinegar. Mixing together these two common household cleaners creates potentially lethal chlorine gas
  • Oil of cloves kills mould spores. Mix a teaspoon of clove oil into a litre of water, and spray lightly over hard surfaces to kill spores. Wait 24 hours, and then clean the area using white vinegar
clove oil

It is recommended to throw away any soft furnishings – furniture or clothes that have been affected by mould. But if you cannot bring yourself to, you can treat using clove oil or salt water.

  • To treat mould on leather or timber, mix a quarter of a teaspoon of clove oil into 250 millilitres of baby oil. Wipe with a cloth over the affected surface. 
  • To remove mould from fabrics, dissolve 1 kilogram of non-iodised cooking salt into 9 litres of water. Soak the item overnight and drip-dry slowly. 
  • To clean carpet, mix 2 tablespoons each of bi-carb soda, white vinegar and methylated spirits, with 2 teaspoons each of eucalyptus and glycerine.

And what about the cost of mould damage? 

If your property has been affected by mould as a result of floods, you may be eligible for cash grants, including emergency temporary accommodation, disaster clean up and recovery payments to repair damage, and bereavements payments to pay for funeral costs and other expenses. 

  • NSW government is offering disaster recovery payments: click heree
  • QLD government is offering disaster recovery payments: click here
  • The Australian Red Cross is offering relief grants and bereavement grants: click here
  • St George Bank is offering cash grants for small businesses: click here
  • Commonwealth Bank is offering cash grants for not-for-profit and community organisations: click here

If you have building and contents insurance, check if your insurance covers sudden and accidental damage.

In most cases, mould damage is not covered by building and contents insurance unless it has been caused by an event that your insurance covers, like burst pipes and storm/flood damage.

dollars

“Building and contents policies will cover mould damage if the mould damage has been caused by an insured event at the insured property,” An Insurance Council of Australia spokesperson told The Green List. 

“Mould damage that has occurred as a result of atmospheric conditions (or other cause), and not by an insured event at the insured property is unlikely to be covered by a policy.” 

So if a policyholder has home insurance that includes cover for flood, mould as a result of flooding at the insured property would theoretically be covered under that insurance, explained Liam Walter, senior advisor mitigation and catastrophe management at Insurance Council of Australia.

As to if you are renting, it’s not clear-cut who needs to fix mould. 

According to NSW Fair Trading, the responsibility for mixing mould in a rental property depends on the cause of the problem. 

Either the tenant and landlord may be responsible for mould damage, depending on the circumstances.