Black Mould and Bathrooms: What You Need to Know

It’s not uncommon to discover black mould creeping into the bathroom. This living, feeding fungus works its way into moist environments before spreading along walls, ceilings and even furniture. In most cases, the unsightly substance is harmless, doing little more than messing with the aesthetics of a home. However, there’s potential for black mould to encroach on your respiratory system, raising health concerns.

So why does black mould form in the bathroom, and more importantly, what can you do to eliminate it? Here’s what you need to know:

Why is Black Mould in My Bathroom?

Black mould is not the result of poor housekeeping. It’s actually a sign of a bigger problem that likely stems from poor ventilation.

Mould can grow in any environment with sufficient condensation or humidity. So there are few places more suitable than the bathroom after a steamy shower.

Failing to open a window or switching on an exhaust fan are the primary culprits of moisture and condensation. But even things like a leaking roof, tap or toilet can also spur mould into action.

The issue can also stem from poor wall and ceiling insulation and a clash of extreme differences between indoor and outdoor temperatures. So, points where hot and cold air meets – like a window or doorway – can also cause condensation.

Is Black Mould Harmful to My Health?

According to Healthline, black mould exposure can cause coughing, red and itchy eyes, a blocked nose, skin rash and a sore throat. It can also cause asthma attacks and breathing difficulties for those with chronic respiratory disease.

There are commonly held beliefs that black mould carries serious health risks. Things like headaches, memory loss, cancer and even death have been attributed to black mould. However, a 2017 study titled Mold and Human Health: a Reality Check asserts no evidence supports these claims.

It’s likely that these beliefs are attributed to toxic moulds which are associated with foods, grain and fibres. Still, the proven symptoms of black mould exposure are reason enough to remove it from the home once and for all.

How to Remove Black Mould

It’s important to remove mould as soon as it appears and before it can raise health concerns. However, removing the existing mould won’t stop it from returning, so you will also need to implement a long term solution.

Dr Heike Neumeister-Kemp is a mycologist fondly known as the Mould Lady. Speaking to the ABC, she said the best way to remove black mould is with a vacuum and vinegar.

“Vacuum all the loose spores off,” she said. “Then take a microfibre cloth and use a vinegar solution, and gently wipe off the mould.”

Your solution should be made from 80 per cent white wine vinegar and 20 per cent water.

While many mould removal guides say that bleach is the best way to remove mould, this is a misconception.

“The bleach just takes the colour out, but the fungi are still there, you are just masking it,” said Dr Neumeister-Kemp. “Six weeks later, it appears to come back, but it was never gone.”

Next up, you should be focusing on how to keep the mould from returning. The most effective way to do this in a bathroom is with an exhaust fan, also referred to as an extractor fan.

The exhaust fan is available as a standalone unit or built into a bathroom heat light. You will need to book an electrician to have either one installed, but the initial costs will be quickly outweighed by the many benefits that stem from a mould-free home.

Opening a window fails in comparison, as this can interrupt the climate control of your home and again, extreme temperature differences can clash, resulting in condensation – the thing you’re trying to avoid.

A dehumidifier is a suitable alternative for removing moisture from a room, although a quality unit can be expensive and should only be used as a quick fix. If a dehumidifier is a bandaid, then an exhaust fan is the cure.

If you’re concerned about mould lingering behind the walls or in the ceiling, an air quality expert can conduct appropriate tests. But if the black mould appears exclusively around the shower or a window in the bathroom, then there’s a good chance that an exhaust fan will be adequate for keeping the mould out.