Heavy rainfall, cold temperatures and heaters, combined with poor ventilation create ideal conditions for mould issues in your rental property and the potential to make you sick. 

As winter kicks in, we start noticing a bigger temperature difference between the cooler outdoor weather and warmer indoor areas.

This temperature difference can create an increase in moisture inside, which often appears as water condensation on your windows or walls. This might seem innocuous enough, but this increase in moisture can lead to mould issues in your rental property.

What is mould?

Mould is a fungus that thrives on moisture and feeds on dust and skin cells, making it important to keep your home dry and to regularly clean and vacuum. Mould may grow indoors in wet or moist areas that lack adequate ventilation, including walls/wallpaper, ceilings, bathroom tiles, carpets, insulation material and wood.

Top tip: You're always going to find mould in your shower grout and around your bathroom - it's not a huge concern, just make sure you keep on top of it. If it gets bigger than your hand or you see blotches everywhere, you could have a real problem.

Why is there mould in my rental property?

Using a heater to deal with cold and wet weather can create an ideal condition for mould growth. The problem with mould is that once it’s there, it will spread and spread unless it’s taken care of right away. Mould can be a common issue in homes that aren’t ventilated properly, with humidity and condensation from dryers, heaters, cooking and showering building up the perfect environment for mould growth.

What’s the issue with mould? 

Not only can mould destroy clothes and other household items like mattresses and furniture, it can also be a serious health issue.

Inhaling mould fragments or spores can inflame your airways, causing nasal congestion, wheezing, chest tightness, coughing and throat irritation. Prolonged exposure to high levels of indoor dampness can reduce lung function and cause chronic health problems such as asthma.

How can I avoid mould growth in my rental?

  • When you use your dryer, heater or are cooking at home, ensure you open a window or two to create air flow.
  • Turn on exhaust fans when you bathe, shower, cook, do laundry or dry your clothes
  • Keep your rental property reasonably clean and conduct regular cleaning.
  • Try to limit your use of humidifiers.
  • Open your blinds and curtains to let in sunlight.
  • If you have an issue with water leaks or a plumbing problem (i.e. burst water pipe, leaking roof or a blocked rain gutter), let your agent know.

What should I do if I spot mould at home?

As a tenant, you have a responsibility to properly ventilate your property and provide air flow throughout your home (this is usually stipulated in your lease agreement). If you spot a serious mould issue at home, advise your agent as soon as possible.

There are a few things you can do to remove mould from your home. For a routine clean-up of mouldy spots, use mild detergent or vinegar that’s diluted in water solution (4 parts vinegar to 1 part water).

If this doesn’t fix the issue, and you can’t discard the item the mould has grown on, use a diluted bleach solution (250ml bleach to 4 litres of water) to clean the surface.

Top tip: If you use bleach, it's recommended you use protective equipment (rubber gloves, safety glasses or even safety shoes). Make sure the area you're working in is well ventilated.

Once you’re done, ensure the surface is completely dried. If you have absorbent materials that have been contaminated by mould (such as carpet) you may need have it professionally cleaned or replaced. is Australia's largest company dedicated to renters and is owned and operated by ASX-listed Limited (RNT:ASX). For over 15 years, has exclusively focused on making renters' lives easier by making it easier to find a property, secure it, move in and pay rent.


  1. Hey just a question what if the molds been there since before we moved in (only Just noticed) and I can’t do anything to fix it because of the holes in widows/wall? Just keep letting water in, I’ve told my private landlords and they don’t care/ they knew about it before they rented the property to me!

    • Hi Emily. Sounds awful! I would suggest putting this in writing to your landlord and seeking an official response after explaining your concerns about the presence of mould in the house and the potential problems that could arise if it’s not looked at. If the mould is only going to get worse because of a structural issue with the property, that’s likely to come under your landlord’s responsibility to fix. If you have no luck and want some advice specific to your state/territory, here’s a link with contacts for the relevant tenancy bodies: Hope this helps!

  2. Hello, we have just moved into a newish apartment. The ensuite bathroom does not have an extractor fan and the walls run with condensation wetting everything in the bathroom. We do leave the tiny window open put this is not enough! Can we ask the landlord to install one? Also the extractor fan does not work over the stove and again leaves bad condensation in kitchen, dining area. Again we open windows, but not good enough. Any help would be appreciated ?