Bathroom smells – possible causes & how to get rid of the smell

Do you have a smelly bathroom?

There are many reasons why your bathroom might smell. The most common culprits include mould, mildew, and bacteria that thrive in moist environments like bathrooms. These organisms release stinky compounds into the air that can make it seem like there’s an actual sewer coming up from your toilet or sink drain! But don’t worry—we’ll help you get rid of these smells for good so you can enjoy a fresh-smelling bathroom again.

1. Mould and Mildew

The most common cause of bathroom smells is mould and mildew that can be caused by a leaking pipe or plumbing fitting. Investigate areas that may be damp from a small water leak or water splashing from the shower or vanity. Common spots include inside or under the vanity cabinet or the wall behind the toilet.

What can you do about mould problems?

There is not much use in trying to clean away the mould or mildew if the leak is still there. If you discover a water leak from a pipe or drain that is causing the mould issue contact your local plumber for repairs to prevent the issue from reoccurring. If you can’t work out why the mould growth is occurring contact your plumber who can carry out a leak detection service to find and fix the leak.

Bathroom with toilet

2. Low water levels in the toilet trap

If your bathroom smells a bit like a sewer, make sure there is enough water in the toilet bowl or trap.

Odours can develop when there’s not enough water flowing through your pipes to wash away waste materials and excess water from cleaning. Your best bet is to try to flush the drain yourself to see if it helps reduce smells coming from the pipe before calling a plumber to check it out for you.

There is a specially designed drain trap that P-shaped pipe behind the toilet or a U-shaped pipe under your sink which prevents sewer gases from entering your home. This pipe should always be filled with water to prevent any smells from backing up into your home.

What can you do about the low water level in the trap?

If you’re noticing smells coming from your drain, there are some things you can try at home before calling a plumber. Pour a bucket of water down the toilet to top up the water in the trap.

Once you have filled the trap you can help eliminate the smell by pouring 1/2 cup of baking soda down your drain and then following with 1/2 cup of white vinegar. The mixture will start to fizz as soon as it hits the drain so be careful not to pour too quickly! Once the fizzing stops after about five minutes, run very hot water down the drain to help clear the odour.

You may also want to consider getting a new toilet with an efficient flushing system if this issue is happening frequently to avoid having the same problem again in the future. Your plumber will be able to provide specific advice on the best course of action.

Bathroom vanity and mirrors

3. Sewer gas

Sewer gas smells can be caused by issues like a backed-up sewer line, a clogged pipe, or a blocked plumbing vent that’s allowing gas to escape into your home. This problem is often solved by a plumber, but if you think there might be a blockage in your drain pipe leading to the sewer line, it’s worth trying one of these DIY remedies:

What can I do about the sewer gas smell?

If you’re experiencing sewer gas smells in your bathroom, there are a few DIY remedies that might help as well as calling a plumber to check out the pipes under your home. You can try pouring 1/2 cup baking soda followed by 1/2 cup vinegar down the drain and letting it sit for 5-10 minutes before running very hot water down the drain.

Vanity basin and tap

4. Water supply

Sometimes the problem with bad odours coming from the sink can be as simple as a slow water supply or even an overcrowded drain trap (which is why it’s important not to pour chemicals like bleach down your drains).

What can you do?

The first step would be to try and clean out any gunk that has collected in the sink drain trap.

If you recently renovated your bathroom and were using chemical cleaners like Draino on porcelain surfaces such as sinks and toilets, this might be enough to cause foul smells in your bathroom. The chemicals in Draino will leave a thin, but extremely hard water spot and can even result in bleach spots on your porcelain surfaces if it is not removed immediately with the proper cleaners (and we don’t recommend using bleach products often since they can corrode your sink or toilet surface).

If you’re experiencing really bad odours from your showerhead, try removing it and scrubbing it clean with white vinegar.


5. Dirty drains

Hair, soap scum, and other debris can build up in your bathroom drains over time, causing them to smell bad. One of the most common causes of bad smells from your drain is a blocked or excessively slow-flowing drain, which can be caused by large amounts of hair and soap.

What can I do about dirty drains?

The best way to fix this issue is to use a plunger on your drain at least once a month to keep them clear.

To unblock a clogged or slow sink: Fill it with water as far as the overflow holes, and work the plunger up and down vigorously as you try to clear out as much of the blockage as possible. This will break up the blockage so you’ll be able to pull it out with pliers more easily afterwards. Pour boiling water down the drain after unclogging it—the hot water will help melt the remaining soap scum.

6. Improper bathroom ventilation

If your bathroom doesn’t have adequate ventilation in the way of windows or an exhaust fan it could lead to moisture buildup which causes mould and mildew problems.

How to maintain effective ventilation in the bathroom

Ensure that your bathroom has good ventilation by installing an exhaust fan, they can be very effective at quickly removing hot air and moisture. Get in touch with your local electrician to get one installed in your bathroom.

If you’re struggling to get rid of a bad odour in your bathroom in Brisbane, Gold Coast or Sunshine Coast areas our experienced plumbing team can help find the source of the problem, give Fallon Solutions a call today.