Mould is the 'tip of the iceberg' for health problems and home deterioration

Watch: How to rid your home of mould after flood, heavy rainfall

Latest in Lifestyle

Where is it coming from and how do you rid your home of insidious mould?


Heavy rain across much of the country has led to perfect mould-breeding conditions.

Areas of high humidity are prone to mould at the best of times. But even environments typically considered to be drier might be experiencing rising dampness this year.

Where is it coming from?

Mould thrives in any humid, wet environment. But there are two main ways that mould manages a foothold in homes. It can either come through liquid leaks or through warm vapour.

The first reason is perhaps the more obvious. Homes that have experienced water damage, either through flood or plumbing leaks, are more prone to mould.

But secondly, mould thrives in homes where humid air exists.

"So we have had in Queensland and NSW particularly weather that really has created very high outdoor humidity and that air is coming indoors," said Brad Prezant, director of Prezant Environmental.

"And if we add to it with things like showering, and cooking, and possibly even using a dryer that's not vented to the exterior, then we're going to add to the humidity that's already present."

When that warm, humid air touches a cold surface - for example, a cold window or ceiling - then it produces condensation and that vapour air ends up promoting mould growth.

What's mould doing to our health?

Rising damp is not good for the body and living with mould can take a serious toll on the health.

Depending on the conditions of the mould, the health response could be anything from more frequent illnesses to severe allergic reactions.

"All of us are susceptible to a number of health outcomes that are associated with damp housing," Mr Prezant said.

"And of course, we spend a long time in our houses, you know, with lockdowns we might spend 24/7 there, but even in normal circumstances, we spend typically 16 hours a day in our homes.

"So when we have indoor dampness, it's like a biological spark that permits all kinds of things to begin happening."

Mr Prezant has had 40 years of experience in environmental consulting, and described visible mould as being the "tip of the iceberg".

HOME INVADERS: Homes may be grounds for mould growth if they have experience water damage, or a full of humid air.

HOME INVADERS: Homes may be grounds for mould growth if they have experience water damage, or a full of humid air.

It is the visible sign of a thriving ecosystem of microorganisms that may contribute to ailing health.

"So just like we have microorganisms that are fungal growing, we also have bacteria that might be proliferating," Mr Prezant said.

"We have things that we can see, like the dust mites that feed on mould and it's almost like an entire ecosystem begins with that biological spark created by the dampness."

Mould may trigger a variety of responses in a person. Frequent common cold-like feelings including a runny nose, cough or other upper respiratory symptoms are common.

In some people, skin aggravations such as eczema may even result. Worryingly, mould may also cause bleeding, cramps, joint pain or chronic fatigue.

"I like to think of it as biological flotsam and jetsam that floats around, gets caught in the carpeting and in the upholstery, and every time you move and walk, you're releasing that into the air and then you're breathing it and it's a bit inflammatory when it gets into your upper or lower respiratory system," Mr Prezant said.

"And then there's a maybe one out of every five persons who actually are allergic to some of the things that are present in the air.

"An allergy is a different thing entirely. We've seen an increase in asthma both in children and adults over the last several decades. And, you know, asthma can be quite concerning.

"So it's important that we try and keep our homes free of dampness in order to prevent all of those types of health issues."

Does mould survive better on certain materials?

Porous, organic materials tend to be a haven for mould growth.

While wood, paper and chipboard may promote mould infiltration, something like a concrete block will only be subject to superficial mould growth.

"So if there's going to be fungal growth on the surface of concrete block, it would have to be on a paint layer or dust that's accumulate on the surface," Mr Prezant said.

"But the mould is not going to be able to actually decompose the concrete.

"If we have something like plasterboard, which is gypsum with paper on both sides, that paper is very vulnerable to fungal growth.

"So if there's condensation on that paper if that plasterboard sits in liquid water and it wicks up into the gypsum, then basically you have a sponge with food on both sides.

"And there's a lot of moulds that are very, very happy to eat paper, in fact, we've even half-digested it for them from its original wood state, by pulling out all the lignans, all the glues that hold those cellulose fibres together."

So, if your home is built of anything other than concrete, does that mean you're doomed to a life of mould infiltration? No, not necessarily, but you will have to work to keep your home dry.

There isn't much you can do to stop humidity outside your home, but you can limit how much comes inside.

"So if you have a [clothes] drier and it's not a condenser type drier, in other words, it doesn't collect the water that's coming off your clothes or if you're drying your clothes indoors on lines, OK then you're adding humidity to the air," Mr Prezant said.

"Minimising the amount of humidity you add by not doing things like that, by ensuring that you have good bathroom ventilation when you shower, by ensuring that you have good kitchen ventilation and checking to see that when you turn on the fan, it doesn't just blow it out back into the kitchen, that it actually exhausts it outdoors, and if you don't have that equipment installed then opening a window or ventilating while you're producing indoor moisture is a good idea."

If none of that seems to be helping your mould situation, consider investing in a dehumidifier that will suck the moisture out of the air and convert it to liquid that you can then dump down the sink or toilet.

How do you combat mould growth?

The answer is simple, keep your house dry. But, how do you actually achieve this? Especially in a year that has been as wet as this one has been.

As with most things, prevention is better than a cure.

"It doesn't do a lot of good to clean mould if you allow the conditions that caused it to grow, to remain," Mr Prezant said.

"So maybe everybody has had that experience. If you go into the bathroom, it's mouldy, you clean the mould off and a week later it's all returned.

"The key here is if you keep the surfaces dry if you keep them below a certain moisture content, then you won't get the mould growth."

If mould has gathered on treated wood or laminate, then it can be simply wiped off with a microfibre cloth moistened with water and some surfactant, a mild dishwashing liquid will suffice. If you keep that area dry in the future, it will prevent regrowth.

But if you have extensive mould, you may need to consult a professional who may need to do some structural drying.

They will have access to heavy-duty wet vacuums that can suck water out of materials more thoroughly.

If you've had a water leak or flood in your home, you will need to get rid of any porous materials that have been soaked.

But if you deal with escaped liquid in your home as fast as possible, you will hopefully prevent mould from growing.

So, if you have a plumbing leak, clean and dry the area as soon as possible. Then monitor the situation for any early signs of mould growth.

The story Mould is the 'tip of the iceberg' for health problems and home deterioration first appeared on Newcastle Herald.