Loo Academy

Mushroom Growing in the Bathroom: Why & How to Prevent It

Mushrooms, dark green, and sometimes black masses can grow in your bathroom in different sizes and patterns.

Typically, mushrooms grow in the moistest bathroom areas and you may notice them around the shower grout, shower drain, bathroom walls, and bathroom floor corners.

And if the unpleasant sight wasn’t enough, you can always tell there are mushrooms sprouting in your bathroom by the musty odor.

bathroom mushroom

As mushrooms are a type of mold, they must be removed to avoid harmful effects on your health. Here’s everything to know about eliminating mushrooms in your bathroom and preventing them from growing again.

Why Are There Mushrooms Growing in the Bathroom

Mushrooms are fungal spores, tiny single-celled organisms present in the air, clothing, window screens, plants, and many other places. Having mushrooms in the bathroom is a clear indication of three things: your bathroom has insufficient lighting, high heat, and high humidity.

These conditions support single-celled organisms to come together, start germinating, and form mushrooms as you see them in the bathroom.

If your bathroom has these three factors, you bet that mushrooms will start growing.


All types of molds, including fungi like mushrooms, thrive where they can find water for growth and nutrition. It’s why the bathroom is the perfect area for them, especially the shower area that often gets pretty damp.


Mushrooms grow where it’s warm, typically between 77 to 86 degrees. They will not grow if the temperature is below 40 degrees. Therefore, if your bathroom is usually warm, for example when there’s a heater working or when you often like taking long hot showers, mushrooms are more likely to grow there.

Insufficient Lighting

Low lighting isn’t directly related to mushrooms growing in the bathroom. Nevertheless, darker areas have higher humidity. Hence, damp nooks and crannies in the bathroom make a suitable breeding ground for mushrooms.

Where Can You Usually Find Mushrooms Growing in the Bathroom?

Like all types of mold, mushrooms in the bathroom grow in areas with low light and those that stay moist and warm. Given the right conditions, mushrooms can grow anywhere in your bathroom. But you can usually notice them growing from the bathroom floor and walls, especially on the tile grout. They can also grow on bathroom ceilings, especially if the ceiling is old and damp.

Mushrooms thrive in damp areas, so they are also common in shower areas, especially on the shower drain. A leaking toilet also makes an attractive place for mushrooms to grow in the bathroom.

Are Mushrooms in Bathroom Dangerous?

There are many kinds of mushrooms that can grow in the bathroom. While plenty of them are harmless, some are incredibly dangerous when inhaled or ingested. Poisonous mushrooms can cause shortness of breath, other respiratory issues, and in severe cases even death.

But generally, mushrooms do not pose a significant risk to health. The real danger about having mushrooms growing in the bathroom comes from accompanying threats.

Where mushrooms grow, there’s a huge risk that it also serves as a breeding ground for more harmful mold growth like black mold. And where this mold and mildew can flourish, you expose yourself to risks like severe respiratory illness and serious allergic reactions.

For this reason, it’s always smart to choose the safest route and get rid of any mushrooms in the bathroom, whether they are a health hazard or not.

How to Get Rid of Mushrooms in the Bathroom

As soon as you notice mold and mushrooms growing in the bathroom, act right away before they spread widely. And no matter what remedy you use, don’t forget to wear gloves, a mask, and other protective gear.

Pick the Mushroom Off the Bathroom Floor

The initial removal of mushrooms that have already grown large is as simple as picking them up off the bathroom floor, wall, or ceiling. But remember, use gloves when picking the mushrooms up. Never use your bare hands in handling any type of mold or fungus as it may be toxic.

Use Bleach Chloride on Tiled Walls

Once you’ve removed larger mushrooms growing in the bathroom, it’s important to clean the area to get rid of any remaining mushroom spores. Clean the bathroom using a 1:3 bleach to water solution, spraying the cleaner before cleaning affected areas with a brush.

You might need to make several rounds of cleaning to ensure the full eradication of mushroom spores in the bathroom. Meanwhile, if you don’t want to use bleach, any household cleaner and disinfectant containing benzalkonium chloride will also be effective in removing mushroom spores.

How to Keep Mushrooms from Growing in the Bathroom

So you cleaned the bathroom floor, walls, and the shower drain from growing mushrooms. But that’s only a temporary solution. Unless you take necessary action, mushrooms will keep growing in the bathroom.

These tips will help prevent another mushroom from growing in the bathroom.

Ensure Proper Ventilation in the Bathroom

Excess moisture that allows mushrooms to grow in the bathroom is often a result of poor ventilation. Making sure that the air inside the bathroom is moderately dry makes the space less welcoming for mushroom growth.

So, ensure that the bathroom has proper ventilation. Open the bathroom window or turn on the exhaust fan, especially after a hot shower or bath.

Fix Bathroom Leaks

Another way to keep the bathroom dry is to make sure that you repair any leaks. Inspect your bathroom plumbing and ensure there are no broken pipes, leaky faucets, or dripping showerheads.

If you deny mushrooms or mold the moisture it needs to grow in the bathroom, they are less likely to start sprouting again.

Keep Bathroom Towels and Rugs Dry

Fibrous in nature, fabrics like your bathroom towels and rugs are a welcoming place for molds to root, particularly if they are frequently damp. Once fungi grow in there, it will be hard to get rid of them, so you’ll have to throw these towels and rugs away.

Always keep your towels or any fabric in the bathroom dry. If you are using shower curtains made of wool or cotton, consider using nylon shower curtains or curtains with mold-resistant film or coating. 

Consider Using a Dehumidifier

If excess moisture is a massive issue in your bathroom, even with the bathroom window opened, consider running a dehumidifier to lower the humidity and prevent mushroom growth.

Clean the Bathroom Regularly

Deep cleaning should be a routine in your bathroom, once or twice a month, whether you notice mushrooms growing or not. Besides mopping with soapy water, consider disinfecting the bathroom floor and walls with a mixture of bleach and water.

Get Rid of Bathroom Mushrooms For Good

Eradicate mushrooms growing in the bathroom using the steps above. You can also use a fungicide to ensure that mushrooms don’t grow in your bathroom again.

When mushrooms begin to grow in your bathroom, it’s a clear sign that you have bigger issues. One of the main reasons is excess humidity in the bathroom caused by poor ventilation. Even after using cleaners and fungicides to get rid of mushrooms, reducing humidity in the bathroom is essential.

Similarly, rotten wood in the bathroom should be removed to avoid future bathroom mushroom problems.