“The day I moved into the house, I recall thinking, ‘I am not sure I can live here.’”

So went the refrain of one unidentified householder (whom we’ll call ‘Tom’) who forwarded a submission to last year’s Senate Inquiry into Biotoxin-related Illnesses in Australia.

Tom’s parents had purchased a home in the Northern Rivers of NSW. Unbeknown to them, the building had extensive water damage. Holes in the tin roof had not been repaired. Internal gutters on some parts of the roof had rotted. As a result, insulation bats were mouldy. Courtesy of poor maintenance on the roof (a non-waterproof silicone had been used to repair the seal around a pipe), water ran down the inAdd Newside of the kitchen wall.

As well, one bathroom had no shower membrane, a cracked tile and extensive black mould abutting the wall.

The day he moved in, Tom felt sick. His symptoms included insomnia (waking every few hours), chronic fatigue, impaired short-term memory and chronic gastro-intestinal and sinus issue.

‘Tom’ is not alone. Another submitter, ‘Mary’ and her partner brought a home in 2007 which had been built three years earlier. A building inspection at the time of purchase indicated no problems.

Two years later, small leaks appeared. This was supposedly addressed and sealed by the original builders. Through a run of dry weather, no further leaks occurred for several years.  Following a change in weather patterns, however, significant leaks began to appear in the kitchen during storms and black mould began to appear around the kitchen ceiling.

The cause was found to be a latent defect in construction of the balconies whereby the fall was incorrect and they fell back toward the house. The balconies had been waterproofed before this had been corrected. The fall was adjusted by the tilers using porous cement before tiling and without further waterproofing. As a result, each balcony had effectively become a swimming pool. Wall cavities had become waterlogged to the point of not being able to hold any further moisture. In heavy rain, it would leak through to the kitchen ceiling. Mould which had grown throughout the wall cavity in the insulation began to grow on the ceiling.

Examples such as these highlight problems with mould and water-damaged buildings in homes throughout Australia.

The prevalence of this is unknown. Between December 2015 and February 2016, the Australian Building Codes Board (ABCB) conducted a survey of building practitioners to gather evidence on the extent of problems in Class 1 buildings (houses) and Class 2 buildings (apartments) in relation to condensation – one common cause of mould. That survey, which received more than 2,000 responses, looked at buildings aged from two to five years and from ten to fifteen years. According to the results, it appears that condensation is present in around one third of all Australian homes. An earlier estimate by the World Health Organisation in 2009 suggested that dampness may impact between ten and fifty percent of indoor environments in Australia.

Action is happening. Last October, the aforementioned Senate Inquiry released its report and made seven recommendations for change.

These called for:

  • More research into potential health impacts of mould/dampness exposure, the prevalence of dampness and mould in the built environment and advice on mould prevention and removal.
  • Research into possible standards and/or accreditation requirements for the mould testing and remediation industries as well as greater regulatory oversight of these industries.
  • Tenants in rental properties, aged care facilities and social housing to be given information about either previous or existing mould and water damage problems prior to entering into a lease.
  • Further research into the adequacy of current NCC requirements and standards in relation to the prevention and remediation of dampness and mould in buildings.
  • Several actions to improve the diagnosis and treatment of patients presenting with complex illnesses such as Chronic Inflammatory Response Syndrome which are difficult to diagnose.

A naturally occurring type of fungi, mould produces tiny particles called spores which are carried in the air and which help it to grow and spread. Whilst commonly found outdoors, mould can also be found in indoor environments and may appear in areas of buildings which are poorly ventilated and which become damp or wet.

In some cases, exposure to mould or dampness can affect health. According to the World Health Organisation, there is an association between exposure to mould and conditions such as asthma, alveolitis and mould infections among susceptible individuals (typically those who are immune system compromised.) Symptoms can include nasal congestion, sneezing and coughing, respiratory infections and exacerbation of asthma and allergic conditions.

As well, some have linked exposure to mould with a range of symptoms associated with a biotoxin illness known as Chronic Inflammatory Response Syndrome (CIRS).

All this raises questions about how Australia is performing in managing the mould problem and what more can be done.

Dr Tim Law, an architectural scientist and principal of ARCHISCIENCES, says estimating the prevalence of mould in Australian homes is difficult as no large scale data has been collected.

Speaking of the aforementioned ABCB survey – which he along with a team of statisticians analysed – Law points out that condensation is only one source of mould in buildings. Other sources include water ingress through leaks in cladding or flashing and water loss events from burst pipes.

Interestingly, Law observes that new homes did not fare any better or worse compared with older ones in the aforementioned condensation survey.

Within buildings, he says mould spores can enter either through building materials (for example, they could have been existent at the processing plant where the plasterboard was made) or through environmental sources. The latter could occur where, for example, buildings are near wetlands where there is a lot of fungal growth.

Indeed, he says mould growth is evident in most houses if you know where to look. In warmer climates, mould will frequently be found in air-conditioning; in cooler ones, growth is most active in interstitial spaces such as the ceiling, wall and floor.

Asked how Australia is performing, Law says we are behind international peers in recognising the implications from mould in buildings and implementing basic requirements that homes should be free of moisture problems.

He says Australia can learn from countries which have pursued energy efficiency and encountered condensation issues because of greater airtightness and associated lack of ventilation. He says countries such as Canada and Ireland have handled this through new vapour management requirements in building codes. Australia could replicate many of these code provisions.

Dr Cameron Jones, chief executive officer of environmental lab testing consultancy Biological Health Services, offers a complementary perspective.

Jones expresses disappointment that the inquiry focused principally on health and largely ignored the effect of poor indoor air quality and water damage on buildings themselves. Moisture build up in homes leads to cracking, structural decay and other impacts which over time drive a loss of amenity, poor insulation and greater heating costs, he said. Whilst these in turn may impact upon health and safety through the accumulation of unwanted biological elements, Jones says water damage and mould should be seen as a building problem which also may potentially impact health rather than predominately a health problem.

According to Jones, there has been a rise in the number of reported problems relating to indoor air quality and mould. Nonetheless, he says this reflects growing awareness of the probability of indoor air quality problems more so than any underlying increase in mould related prevalence. Indeed, he says this has led to some believing they had problems when in fact this they do not.

“Certainly over the last decade, the number of telephone calls regarding concerns about indoor air quality and mould has been increasing exponentially,” Jones said.

“Fundamental reasons why a home may display poor indoor air quality or mould, however, remain the same. As people become more aware of the possibility of adverse indoor air quality, there is a cohort of people who have no indoor air quality concerns who believe they do so.”

According to Jones, mould growth can be caused by several factors. Whilst many understand that mould can be caused by plumbing breaches, he says more often it results from long term problems with the building. These can include old insulation in the ceilings and condensation which forms as a result of thin window glass. As well, there could be water breaches, unintended plumbing failure or inadequate waterproofing during construction. Materials, too, can be problematic. “In the case of lightweights construction materials and with the introduction of energy efficiency provisions, having a dominance of plasterboard, Jones says which is thin and porous means that mould grows if this becomes damp.”\

Finally, Jones says he gets around 30 jobs each year where water damage occurs in the frame and truss during construction. This can happen where there is a delay and parts of the frame are left to sit for months in a partially erected state. This, he says, often reflects poor site supervision and failure to make properties watertight between the base and the frame stage. Often, he says, builders and tradespeople will cover up damage caused by water and mould through internal wall and ceiling linings.

Going forward, Law and Jones would like action in several areas.

Law would like more action on condensation. In particular, he says building surveyors need to be educated in psychrometry and environmental health officers need to be educated in microbiology. Whilst he acknowledges that both of these types of professionals have roles which are general in nature and involve consideration of numerous issues, he says these specialisations are the primary means through which regulations and standards can be enforced.

In enforcing standards, he says awareness about microbiology is important. For environmental health officers, he says it is difficult to understand where to find mould and whether it impacts people’s health without understanding basic microbiology. As for surveyors, he says they should understand how vapour moves into the building and how it can condense.

Jones, meanwhile, would like greater awareness that mould is a realistic health problem for some people and cannot be dismissed as causing problems only for minorities. He says issues of health, inflammation and chronic illness can occur to anyone who is subject to overexposure from water damage. “This is especially the case for those who have a compromised immune system, or persons about to undergo surgery or receiving chemotherapy or on multiple courses of antibiotics.”

In terms of what home occupants can do, Law said the focus must be on delivering better buildings in the first place.

Beyond that, he urges householders to implement steps in regard to moisture management.

The first part of this involves measurement. On this score, Law recommends a thermo-hygrometer – a thermometer which also provides indications of relative humidity.  In a cool climate, he says this should be placed near a window. Households should aim to maintain this under 6o percent RH (relative humidity).

As far as possible, moisture should be limited at the source, such as the laundry, cooking area and shower.  Laundry dryers should be ducted externally. Where this is not possible, a condensing dryer should be used. Cooking should be operated with an externally flued hood – with windows open to make up air. For showers, Law says extraction fans should be ducted externally and should run for about fifteen minutes after the shower. Once again, Law says windows need to be opened or the fan will struggle to move the dense droplet-laden air. For bedrooms, he suggests a dehumidifier (it needs to be a desiccant type dehumidifier for cool climates). Similarly, he says advises that a dehumidifier be used if you hang wet towels in the bathroom.

In his own case, Law personally uses a dehumidifier on a timer several hours per days. As well, he has cold showers even during the cold Tasmanian winter – though he acknowledges that not everybody is suited to this.

Notwithstanding energy efficiency (and security) considerations, Law says it helps to keep windows slightly ajar. Whilst he acknowledges the effect of this on the energy efficiency and environmental sustainability of buildings, he says safety and health should rank higher than energy efficiency in priority.

Jones says several things can be done.

First, where condensation does appear on the windows, this should be mopped up with either disinfectant wipes and a towel. Window coverings such as curtains and blinds should be looked at and raised to ensure they are not sitting in pooling water over winter. Where possible, ventilation should be maximised. To maximise evaporation, rooms should be exposed to sunlight as much as possible.

For mould problems which occur other than through window condensation, Jones offers several strategies. To maximise airflow, a gap between furniture and walls should be maintained. Wet clothing should not be dried indoors. Bathroom extractor fans should be used. If these vent directly into ceilings rather than outside, an IXL infrared extractor will help to minimise condensation in the internal bathroom room volume. Extractor fans should be used when cooking. In cases where multiple families reside under one roof, occupants should ventilate as much as possible to reflect the additional load in terms of cooking and bathing.

Jones says a common misconception involves ideas that keeping homes closed up and airtight is helpful in minimising the likelihood of infections for children. In fact, he says homes should be well ventilated.

Overall, Jones reiterates that he would like more attention on the building side of the debate.

“Really I think we need to stress the attention to the building side,” Jones said.

“These (dampness and mould) are building problems, and due to building problems they can lead to health problems. It’s not the other way around.”