Wes Quick, director at ventilation firm Expella, shares his top tips for preventing mould and funky smells from taking over your bathroom.

A damp, poorly ventilated bathroom is a breeding ground for mould and funky odours, making it unpleasant to use and downright embarrassing when you have guests over.

There are health considerations too: mould is a fungus that, if left untreated, can produce harmful toxins and irritants. According to the Australian Building Codes Board (ABCB), a family of four produces on average seven or more kilograms of water vapour per day from showering and bathing. Without sufficient ventilation, this saturated air creates the perfect conditions for mould growth.

Fortunately, there are several things you can do to keep the area mould-free and smelling sweet.

What can I do to keep mould and odours at bay? 

  • Clean bathroom surfaces and fixtures (bath, toilet and vanity) at least once a week.
  • Get into some good daily habits: keep a squeegee in your shower and give the surface a quick once over after showering. This will cut down your cleaning time and prohibit mould growth.
  • Remove hair from the shower drain or any gunk from the shower base before you step out after washing.
  • Keep the bathroom door open when the room is not in use to improve air flow.
  • Open windows after showering or bathing to let out the steam and moisture.
  • Install a ventilation system to remove moisture and odours from the bathroom and draw fresh air into the space. Run it before, during and after bathing or using the bathroom.

Tip: A ventilation system with a run-on timer is a smart investment as it will automatically run the fan for a set period of time after the system has been switched off – say 10 minutes – to remove any lingering moisture or smells.

What else I can do? 

  • Wash towels weekly – damp towels can add to the stench in your bathroom.
  • Add a few plants to your bathroom to help absorb some of the moisture in the air. Moisture-loving plants, such as maidenhair ferns and peace lilies, do particularly well in bathrooms.

Should I keep the shower curtain open or closed after use?
I’d suggest leaving it closed (with the curtain extended) as this will allow it to dry out more thoroughly, reducing moisture in the bathroom.

Where does bathroom mould start? 
Generally, in corners such as wall and floor junctions. If wall surfaces are cold enough, mould can also form on the grout between the tiles.

How do you know when the bathroom has been ventilated enough? 
Look at the mirror – when there is little or no steam on the surface, your bathroom has been sufficiently ventilated.

How does a bathroom ventilation system help?
A bathroom ventilation system is the fastest and most effective way to remove moisture and odours from the bathroom and draw fresh air into the space, creating a healthier, fresher environment. While it won’t stop mould from developing, it will prevent it from becoming overgrown and potentially toxic.

What are the main types of systems?
Wall fan: 
This is the most cost-effective way to ventilate your bathroom. These fans are designed to move large volumes of air short distances, for example through a wall to the outside of your home.
Ceiling-mounted fan: This is another cost-effective solution, and it’s generally more powerful than a wall fan. A ceiling-mounted fan is hidden by a cover plate and the air is usually exhausted through ducting to the outside.
Inline-exhaust system: This is the most powerful, quiet and discreet ventilation solution. The fan is hidden inside the ceiling and connected to a ceiling grille via exhaust ducting.

What do I need to know before choosing a ventilation system?

  • Choose the right-sized system for the space.
  • Select the right location for the system’s fan or grille. It should be positioned as far away from the replacement air source (such as the door or window) as possible in order to maximise air circulation.
  • Your ventilation system won’t work properly if the bathroom is completely sealed and sufficient make-up air cannot enter. You can ensure that make-up air can enter your bathroom, even when the door is closed, by having a gap (undercut) of at least 20-30 millimetres at the base of the door.

My toilet smells fine… where else could the funky odour be coming from? 
The water in your bathroom’s floor waste (the central drain on your bathroom floor where wastewater from the shower, hand basin and bath flow into) can evaporate, particularly in the warmer months or if you haven’t cleaned for a while. This means there is no separation or safety seal between the bathroom and the sewer. That nasty stench could be the sewer odours travelling up to your bathroom.

To check there’s a seal in your floor waste, shine a torch down the drain. If there is water present, there’s a seal. If it’s dry, there is no seal. If it’s dry, pour a bucket of water down the drain until it fills up. Ventilate the room well, and this should clear up the stench.