Types Of Bathroom Mold (Health Risks & Preventive Measures You Can Take)

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One misconception about mold is that it only grows in old and beat-down homes. This cannot be farther from the truth. Homes, old or new, can develop this problem because mold spores do not depend on a structure’s age to grow. 

Some types of mold cause no harm, but if you don’t deal with them, they can spread hazards for both the structure of your house and your health. Keep reading to learn more about the different kinds of molds often found in homes, and particularly in bathrooms. We’ll also talk about how we can identify them, prevent them from appearing, and the possible impact they have on our health.

common bathroom molds
Protect your family from mold-related danger | Photo by Jessica West

Can You Prevent Mold from Developing?

Fortunately, the answer to this question is YES. For all types of molds, the best way to treat them is to prevent them in the first place.

In most cases, mold spores develop because of some sort of water damage in the room or having consistently damp surfaces that aren’t cleaned and dried regularly. You can see how this can be a problem for the bathroom, but it can also happen in laundry rooms, basements, and kitchens.

Get Rid of Unnecessary Moisture and Humidity

Fix Leaks

Make sure that you fix any pipes that leak. In rooms and areas where water use is necessary, be vigilant in keeping the surfaces and floors dry and clean. Leaky toilets are another major cause of damp bathrooms.  Walls can absorb moisture and humidity (say, from a steamy shower!) and this can be a huge invitation for mold spores to proliferate. The same applies to wooden or tile floors and even your walls!

Damp towels and bathroom robes hanging on hooks can also hold a lot of water. Running them through a quick dryer cycle or just spreading them out to air dry can help keep moisture dry. While electric towel drying racks may seem like an unnecessary luxury, they are another good way to dry out towels especially if you live in a cold, damp climate. While they were very expensive when they first came out, there are many free-standing models like this one that are affordable and don’t require any installation.

Are you thinking of buying an old house and flipping or renovating it? Before you sign those checks, be sure to check with a building inspector to see if it has been cleared of all mold issues.


Install a Bathroom Fan

One of the easiest ways to dry out a room. Ideally, you would have plenty of bathroom windows to let in a breeze and sunlight. Not only does this keep the room smelling fresh but it also keeps it dry and well ventilated and preventing mold and mildew from setting and growing. Unfortunately for many of us with smaller bathrooms, lots of windows are not an option. The next best way to ventilate is to install a bathroom fan. While there are many types of exhaust fans. They are relatively affordable and easy to install, especially if you are already doing a remodel. We recently installed this bathroom fan and it’s worked out well.  

Use a Dehumidifier 

Growing up with a basement in the house, the constant hum of the dehumidifier was always in the background and one of my chores was to dump out the water tank on a daily basis. Luckily these noisy and clunky machines have been replaced by much more energy-efficient and quieter options. There are plenty of great small bathroom dehumidifiers on the market. These do a great job removing a lot of the moisture from the room.

Use an Air Purifier

While you’re cleaning for possible mold-infested areas, make sure to use an air purifier simultaneously. This minimizes the possibility of spreading mold spores further. Today, there are air purifiers equipped with advanced technology that’s aimed at eliminating mold spores from the air in the house, thus avoiding any contamination from occurring. If you’ve been thinking of investing in a good air purifier, this specific benefit might be the nudge you need – it’s a worthy purchase! Just make sure you choose a high-quality one that you can enjoy for a long time.

Coway AP-1512HH Mighty Air Purifier with True HEPA and Eco Mode in White
Coway AP-1512HH Mighty Air Purifier with True HEPA (Image: Amazon)

Use the Right Type of Caulking

By using the right type of caulking material and process, you can prevent mold from growing and spreading in the bathroom. To learn more about this, check out our post on the best caulk for mold and mildew!

GE GE281 Silicone 2+ Kitchen & Bath Sealant Caulk Squeeze Tube, 2.8oz, White
GE GE281 Silicone 2+ Kitchen & Bath Sealant Caulk (Image: Amazon)

Identifying the Common Types of Bathroom Mold

In an ideal world, you won’t need to worry about mold problems – and we won’t wish them on our worst enemies. But if you do, it’s best to keep yourself informed and be prepared should the problem arise. Here are the common types of mold that you’re likely to find growing in your bathroom and other damp areas in the house.


Alternaria porri
Alternaria porri mold spore | Photo: honey-bee on Flickr

This common mold is found both inside and outside the house. It typically shows up in damp areas, such as the shower and sink, as well as areas that are often dimly lit or completely dark. If untreated, Alternaria can lead to allergic reactions and even trigger asthma attacks.


This indoor mold is very common. And while its health effects are minimal at best, we’d prefer to take it out entirely. Once inhaled, common respiratory issues encountered include allergic reactions, irritated lungs, and respiratory infections. (If you’ve been coughing and sneezing for unknown reasons, you might want to check if you’ve got mold growing at home!)


Unlike other types of mold, this type is more commonly found on surfaces, wooden furniture, wallpaper, around windows, caulk, and painted walls. The good news, though, is that these areas are more visible to the naked eye, allowing you to spot them easily. So when you see spotty substances that are either black or pink in color in the areas we mentioned, it’s likely to be Aureobasidium. This mold is very common and can cause allergic reactions to those exposed to it. In worse cases, more adverse reactions can even occur.


This type of mold can often be found in drywall that’s been suffering water damage for a while. You can tell that it’s growing in your home by noticing an old or musty odor in the area.


You can spot Cladosporium in areas that are either warm or cool, such as wooden floorboards, carpets, cabinets, and old fabrics. If you are exposed to this mold and inhale its spores, you can experience a myriad of respiratory issues and even have trouble breathing.


Fusarium equinum from root of horse hair affected by dermal mycosis
Fusarium affected by dermal mycosis | Photo: Arallyn! on Flickr

This type of mold grows in areas that are damp and cool. If you’re using carpeting on your floors, this is a common issue to face. It can also grow in similar fabrics. The usual effect of fusarium includes allergic reactions, inflammation of the respiratory tract, as well as infections.

You can find this mold indoors. Particularly, it likes inhabiting furnishings, the inside of your insulation, carpets, furniture that’s been damaged by water, and other similar areas. Its defining characteristic is its quick ability to grow and spread through the house. You can experience sinus infections, allergic reactions, and lung inflammation.

Stachybotrys Chartarum

Also known as toxic mold and black mold, this type of spore can create mycotoxins. Mycotoxins are highly toxic compounds which when inhaled can lead to sinus infections, breathing problems, asthma attacks, fatigue, and even depression. You can identify the mold through its musty odor. It usually grows in areas that are regularly damp, such as pipes, ducts, and other air conditioning units.

Serpula Lacrymans

Dry rot in brick mould.
Dry rot in brick mold | Photo by David Schott on Flickr

This type of mold is typically seen outside, but can also grow on the inside of your wooden surfaces. Think picture frames, wooden countertops, and cabinets or vanities in the bathroom. The mold causes the wood to experience dry rot, basically since this mold feeds on the wood. You can identify the mold from its signature yellow color.


Another type of mold that grows in damp areas, Trichoderma has been identified as hazardous to your health. You can find it in damp wallpaper, carpets, and similar areas. It also produces mycotoxins that lead to allergic reactions and sinus infections.


You can find Ulocladium indoors and outdoors, often in areas that have been gravely damaged by flooding and other forms of water damage. It grows on walls and other surfaces that have been flooded. It can lead to respiratory infections and allergic reactions.

How to Treat Bathroom Molds

Hopefully, the information we’ve laid down helps you identify the presence of mold in your home. Once you have, the process of treating them is quite straightforward. You can take care of these common household molds using products you probably already have.

First, search the room for any damp or wet crevices and surfaces. Before going in, make sure to wear a breathing mask and gloves for your protection – you don’t want to inhale the mold spores as you’re getting rid of them! For severe cases of mold infestation, you should contact a local expert for profession mold removal near you

Next, seal the area off where the mold is to avoid further spread to other parts of the room.

You can wash the moldy surface with a solution of warm water and detergent.

Next, let the surface dry it on its own. Following that, apply bleach solution on the said surface. Wash it and rinse. Repeat these steps thrice. After the final washing, create a borate solution and use it to scrub the area.

Loudwolf Sodium Borate Decahydrate "Borax" / Fine Powder / 4 Ounces / 99.9% Pure/Ships Fast from USA
Loudwolf Sodium Borate Decahydrate “Borax” (Image: Amazon)
  • Take 10 oz of sodium borate powder and pour it into a cup containing 1/2 cup of hot water. Stir well. That’s your homemade borate solution, which can also be used in treating termites. This particular concentration and dosage are ideal for dealing with molds.

A Final Word

As the mold problem disappears, you probably don’t want to encounter the same issue again. So make it a point to clean regularly and always be vigilant in inspecting any recurring mold. Implementing one or more of the preventative strategies above (fans, dehumidifiers, ventilation, air purifiers, etc) can help from preventing the problem from reoccurring.

These are a natural part of our life, but you don’t need to have them in your home and compromise the health of the entire family. Learning how to identify, treat, and prevent them can keep your family safe, comfortable, and healthy.