And it’s about time you knew how to avoid it…
When you go to the effort of building your own home, the last thing that you want to encounter is a homewrecker such as black mould. Search engines will show you a number of black mould outbreak headlines across Australia. Year after year warnings for asthma and allergies are given amidst heavy rain that sees manifestations of it within cars, houses, pillows, clothing and all different types of fabric.
If it’s not the tropical states such as NT and QLD, where there are loads of possessions becoming infested – Cities across Australia experience ‘crazy weather’ that can trigger heartbreaking manifestations.
One in three homes become affected by toxic mould and a further 1 in 5 rentals become toxic or abandoned due to cosmetic property maintenance procedures.
Floods are causing people to move out of their homes, but in many cases, the less obvious manifestations are just as tragic; possessions are lost and people are forced to move out of the mould.
Even though scientists and doctors are still linking symptoms of illness directly to condensation. The health symptoms are so broad that people are only attributing them to mould after leaving their houses.
Mould and Our Homes
When sitting at the office of a display village, it’s easy to become swept up in your dream vision. But in today’s market, the majority of large standardized home builders are rarely concerned about ventilation. To them, it’s more so about keeping heating and cooling locked inside. This leads to a lack of airflow and air-tightness which creates condensation and mould.
Have you noticed that most Display homes have air conditioning running full time? If they were left with windows open, the uncomfortable heat is unbearable. So if these are the display homes, would you think your home will be any better?
Once there is a build-up of air, the lack of ventilation causes humidity that doesn’t allow for damp surfaces to dry out. Windows and fans are hardly enough to ensure that any stale or water-vapour infused air is replaced; Just as mould decomposes dead leaves and tree’s outdoors, water left on a surface only takes spores 48 hours to start doing this to your house, mostly within the insulation of your home which is unseen.
Most building designers say the answer to mould and condensation problems are unique for every property depending on the size of windows and location of the house.
These are mostly for solutions that are made based on untrailed and un-researched methods of ventilation.
Scientific analysis has been published to suggest that people should use purge ventilation with windows. However, in order for this to happen enough on average, windows would have to be opened for 5-10 minutes every 3 hours, even at night! Newspapers claim that people should resort to their own trial and error processes, but who has time to do that?
Passive House Standards change the game.
Not only is the Passive House able to ventilate with or without opening windows, but the ventilation system will also collaborate with carefully selected building fabrics; clearing vapour from the air across each room. You can easily maintain the highest state of thermal wellbeing. No component of the building would ever allow for mould to prosper.
Lastly, thermal bridges are minimized between the building elements… What does this mean for mould? There is no condensation in the first place. The inner-fabric of the home essentially remains dry, along with the air that is monitored for humidity by the ventilation systems…
Common Preventable Causes:
Whilst there is an increasing number of complaints being made about mould to Australia’s Building Commission, here are some common reasons that buildings are prone to condensation:
- Poorly ventilated roof spaces that breath moisture and therefore mould
- Positioning a home in a water prone area such as a flood plain or a watercourse.
- Lack of drainage that supports the home.
- Planting garden beds against the home.
- Uncontrolled humidity entering the home.
- Concrete slabs and footings in contact with ground absorbing moisture.
- Thermal bridges between building materials where condensation occurs.
- And many more…
Worst Case Scenario
Interstitial condensation is achieved within a 7-degree difference in outdoor/indoor temperatures.
Mould grows in between wall cavities and within the insulation than can not dry out. It often goes highly undetected and as one of the leading causes of indoor air pollution, is most often discovered at the time that building inspectors go through the house; after an offer has been made to sell.
It’s a cause of serious health issues and directly attributed to ‘sick building syndrome’
The building fabrics of a Passive House are designed to avoid and prevent this.
How Does the Mould Spread?
Once dew point starts to occur, water within its gaseous air travelling invisible form will turn into droplets of water. They’re often so harmless that our children might start to draw smiley faces in the windows. You often see it on the lawns, cars and houses where it is quickly forgotten.
Once the mould spores reach a damp surface they start to feed off bacteria, which are just about everywhere within a home. Most buildings and furniture are the ideal feeding ground for mould, and it often becomes difficult to identify the source of the moisture. Opening a window or two might assist, but once the invisible spores are sitting on a surface for more than 48 hours, the microbes will attempt to take over space by producing endotoxins, mycotoxins and all kinds of microbial organic compounds that can dramatically reduce the indoor air quality.
Ensuring that air is cured isn’t as easy as opening a window; Frosty water streaming windows, sweaty looking walls, dampness soaking through, wallpaper peeling, tiles popping off walls… All of these things are tell-tale signs of condensation that still happen within regular homes; placing the home and the people within it at risk. In properties where the air is not cured, there are easily manifestations of mould.
Is your house closed during the day? Overheating of building materials, the thermal mass absorbs the heat and transfers inside by poorly quality government approved walls.
Using design and building software, all 5 elements of achieving a Passive House and reducing humidity or dry air is done through balanced pressure-controlled ventilation. This will ensure the proper distribution of fresh air in all rooms and safe dehumidification of kitchens and bathrooms.
Overall, the ventilation system of a Passive House is about supplying fresh and filtered air, and exhausting polluted from odorous areas and directing flow throughout the house; ensuring that the ventilation functions properly.
The good quality air is an important pre-requisite for a healthy and comfortable living environment. There is no re-circulated air which equals hygienic air quality. The convenient solution is to supply and exhaust air systems with heat recovery.
Do you ever feel that your home feels “stuffy”? Cold/hot spots in different times of the year, this doesn’t happen in a High-performance Home.
Just the right quantities of fresh air that are required for good health and comfort are supplied. Only filtered air enters the living areas, there is no recirculation, which provides hygienic air quality. This is all possible with flow rate adjustment in ventilation systems, automatic volume flow and designed for the volume of air in your home.
Mould and Health Affects
The most important thing about mould in relation to health is its tendency to destroy building materials.
Inhaling or touching mould or mold spores may cause allergic reactions in sensitive individuals. Allergic responses include hay fever-type symptoms such as sneezing, runny nose, red eyes and skin rash (dermatitis). Allergic reactions such as asthma attacks, eye irritants, skin, nose and throat and lungs can also occur due to allergic and non-allergic causes.
Mould has devastating effects on those who can’t make antibodies against it (75% of the population), and research on the extent is still ongoing. Given that fungi and mould have been around for such a long time… Why are they such a health problem now?
WELL, here it is:
Scientists have discovered that the chemical slew of microbes (bacteria and fungi) as well as their by-products (fragments, spores, endotoxins, mycotoxins), are thought to be responsible for the health effects associated with being in a water-damaged building.
Around a quarter of the population have a genotype (haplotype) that does not enable them to produce antibodies to fungi, so what happens every time they walk into a mouldy building? It sets up an inflammatory response that doesn’t switch off.
In contrast, the rest of the population (25%) DO produce antibodies that enable them to recognize and clear these anti-germs from the body automatically.
An inflammatory reaction may cause key neuro-properties in the brain such as: Vasoactive intestinal polypeptide, melanocyte-stimulating hormone and in some cases; antidiuretic hormone, to create illnesses such as chronic fatigue syndrome. 25% of people produce an antibody that can prevent this; that’s why some people get sick while others remain healthy.
Common Health Problems:
- Overly Sleepy? Mould can cause fatigue that upsets the entire ‘circadian’ rhythm. You might fall asleep at your desk, or be tossing and turning at night.
- Common Coughs? You might become prone to cold and flu and suffer on a recurring basis. It’s likely you’ll have a range of symptoms that are potentially treated as common infections, hayfever or pneumonia.
- Super Tired Syndrom? This is the chronic fatigue that causes more than just sleepiness, but headaches, sleep disturbances, brain fog and poor short-term memory.
- Unusual Body aches and pains (Fibromyalgia) with an inability to thermo-regulate; being too hot or cold.
- Excessive urination and/or thirst that isn’t a result of ‘diabetes’.
- The ability to become easily shocked when touching electrical appliances. This is caused by changes in osmolality due to issues with the antidiuretic hormone.
- Symptoms often improve when they are away from the building.
What the Experts Say:
“We can get very irritable; people either get depressed or aggressive, so their behaviour changes,” mycologist Dr Keiki Neumeister Hemp said.
“It can be irritable bowel syndrome, it can be fatigue and all kinds of headaches.”
“In a nutshell, it’s a type of fungi that should be avoided because there is a possibility that they cause severe health effects.”
It is very expensive to get rid of mould once it starts to happen, and so too is an investment in prevention that’s not tried or proven enough.
Curing the air and airways of mould altogether is a key design feature of a Passive House. It ensures that the building and its inhabitants live a long and healthy life together.
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