8 Mould Myths You Probably Thought Were True

8 Mould Myths You Probably Thought Were True

By Ruth MacEachern

Product Manager

Mould spores are prolific everywhere, but not everything you think you know about mould is true. Here are 8 ‘mould myths’ and the actual truths behind them:

Myth 1 - Mould can only grow where it is wet.

This is not true.  Mould initially needs moisture to start growing.  The surface area can then completely dry out, but the mould will still grow because it takes moisture out of the surrounding air. The air would need to have less than 4% relative humidity for the mould to die off.

Myth 2 - Drying the affected area makes the mould go away.

The only solution to reducing or eliminating the mould is to fix the source of moisture, dry out the problem area, and then scrub the surface using a microfibre cloth and a mould cleaning product to remove any remaining mould. Or call in the professionals.

Simply drying the area may slow the growth, but the mould contaminants are still present and could potentially spread into the surrounding air causing an allergic reaction or more dangerously, give off gas mycotoxins, which can cause breathing problems and other severe symptoms if inhaled.

Myth 3 - I can just paint over the mould.

Many people waste huge amounts of money to attempt to paint or re-decorate over mould only to discover that in a few months the mould has reappeared, or the paint has started peeling off. Mould can actually eat the paint, even mould-resistant paint. The mould has to be removed and the source of the problem fixed before it is worth re-decorating.

Myth 4 - You don’t need to worry if you clean it up quickly.

You can only fully clean up if you know how widespread the mould is, and the source of the problem.  Most of the mould is actually invisible so like with the tip of an iceberg, the black or green stuff you can see is just a very small portion of the mould. Most mould is actually see through, and invisible to the naked eye.  Failure to clean up the entire mould and remove the original source of moisture can result in re-growth.

Myth 5 - Mould can be removed with bleach.

Unfortunately, household chemicals such as bleach (hydrogen peroxide) is not enough to remove all of the mould particles. In fact, it can often exacerbate the problem as bleach is a water based cleaner, and if not dried quickly, the mould thrives on the moisture.

And, as before, just removing the mould without fixing the underlying problem and removing the source of water will usually result in the mould growing back. Bleach and the chemicals it contains can also be harmful to humans, so should be used with caution!

Myth 6 - Only Black mould is deadly.

It is true that different moulds have different hazard levels, but mould comes in all kinds of colours: white, orange, blue, black and many more besides. There are over 100,000 varieties of mould, hundreds of which are black. Some are very dangerous; some are mostly benign. There are also moulds in many other colours that release mycotoxins that are dangerous to human health.

Regardless of the mould’s direct impact on people, no mould should be left unattended. Given enough time, mould will decay a structure beyond repair, and often, people with allergies or weakened immune systems like children or the elderly, experience cold symptoms and other health problems when exposed to mould.

Myth 7 - All mould is harmful.

Moulds are used by humans for all kinds of things; cheese, antibiotics (which save millions of lives) to name two were invented with the use of mould. However, the mould growing on your bread or your wall isn’t going to help with your cough. The moulds that take over homes come in all types of forms and breeds. Some are benign; others are deadly.

Myth 8 - A clean or new house prevent mould growing.

New homes are often more likely to have serious mould problems than old homes due to modern construction materials, such as drywall, which absorb more moisture than older products, and take longer to dry. In addition, many of the things we now build houses from contain nutrients mould loves.

New houses are sealed so effectively that they have very little fresh air exchange, so when mould and damp begin to escalate, it becomes concentrated, causing potentially serious health problems including asthma attacks, sinus problems, allergies, fatigue and numerous other ailments.

Mould is also NOT about dirt, or bad housekeeping. Mould is about excess moisture. Too much humidity in the air can encourage mould to develop no matter how clean your home is. If you are worried about mould or the quality of the air in your home, we can help.  An experienced ventilation expert will be able to provide a no obligation, free home survey and advise on the best approach to improve the indoor air quality.