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Top 10 Tips for Identifying and Preventing Mold and Mildew

Catherine Miller
How to identify and prevent mildew and mold
Dark patches on your walls or orange stains on your ceilings? Discovering mold or mildew in your home can be a cause for concern. When mold or mildew spread, it can damage your home and cause health problems for you and your family.

It’s important to know how to identify and treat mold and mildew and know the difference between them so you can take the best course of action. And with the expense and hassle of removal, preventing the problem from coming back or getting worse can save you a lot of time and money!

What are mold and mildew?

Mold and mildew are types of fungi that thrive in damp conditions. They grow from spores that naturally occur all around us. Given the right circumstances, they will start to spread.

Mildew can be powdery and tends to have flat growth on a damp surface. It can start off as gray, yellow, or white before gradually turning black. Mildew is often found in basements, crawl spaces, and closets as well as on textiles such as curtains. 

Mold is thicker and may look fuzzy or furry. It usually grows in patches and can appear green, yellow, blue, gray, black, white, or brown in color. It can penetrate a material rather than remaining on the surface, making it more difficult to remove than mildew. Mold prefers warm and damp locations and can eat away at building materials. 

How to identify mold and mildew

If you have mold or mildew in your home, you may notice characteristic patches that can look like dirt or discoloration. You might also smell the mold, especially in an enclosed space. Mold growing in your walls can cause them to feel wet to the touch or rot away. You may also need to check for mold if you spot signs of a leak, such as damaged paint. 

There are many thousands of species of mold, but the most common ones you may find in your home include:

  • Alternaria: Dark in color with a wooly texture. It’s usually found in locations where there has been water damage.
  • Aspergillus: Gray, black, brown, white, or green and commonly grows on paper, clothing, or insulation materials. It can also be found on damp walls. 
  • Cladosporium: Green or black and prefers wood and textiles. It can develop in cooler locations in the home unlike other species, which need warmth to grow.
  • Penicillium: Green or blue and musty-smelling. It grows on damp materials.
  • Stachybotrys chartarum: Also known as black mold, it is musty-smelling and grows well in damp places or homes with a lot of condensation.

Mildew is commonly divided into two types:

  • Downy: Yellow spots that gradually turn brown. 
  • Powdery: Patches of gray or white that turn brown or black as they grow. 

If you aren’t sure if what you’re seeing is mold or mildew, you can swab the area with bleach. If the patch you’ve swabbed gets lighter, it may indicate mold or mildew. Mildew should be more easily wiped away and will be in flat patches, whereas mold may be more difficult to remove. A wooden surface that has been penetrated by mold may also crumble when tested with a tool like a screwdriver. There aren’t specific mildew testing kits, but you can buy mold testing kits, although these may not be totally accurate. If you are in doubt, you should seek support from a professional.

Issues that cause mold and mildew

Mold and mildew spores can enter your home by traveling through the air or being tracked indoors on shoes, clothes, or on pets. They take root on a variety of surfaces. Mold and mildew thrive in damp conditions and prefer spaces that are dark and have poor air circulation. Basements, crawl spaces, and areas around vents are common places to find growths. You may also have problems in your bathroom if it is poorly ventilated. 

Additionally, water damage to your home following a leak or flood may give rise to mold. Not dealing with the damage quickly enough can give mold the chance to grow. Mold growth can even alert you to a leak you didn’t previously know about. 

Too much condensation in your home can also cause the damp conditions that help mold and mildew spread. This can be exacerbated by behaviors in the home, like drying your laundry indoors, cooking, or bathing. Homes that don’t have enough ventilation can suffer from mold growth, a particular problem in the modern world where our homes no longer have open fireplaces or windows that allow air to flow through the building. 

Health concerns of mold and mildew

Mold and mildew can cause allergic reactions in some people and animals. For example, you may experience sneezing, a runny nose, or breathing problems.

Some forms of mold can cause more serious respiratory illnesses and exacerbate existing conditions like asthma. Black mold can even cause chronic infections and depression. Those particularly at risk include children, the elderly, and anyone with a weakened immune system. Therefore, it’s important to remove mold and mildew from your home as soon as possible to prevent them from spreading and potentially damaging the health of you and your family. 

How to clean mold and mildew

To clean mold and mildew from your home, it’s important to wear protective equipment and clothing such as a good facemask, gloves, and goggles. You should also wear old clothes that can be thrown away at the end of your cleaning. Make sure the space is well-ventilated while you clean and dispose of moldy waste carefully so you don’t spread the spores around your home. 

Mold can be more difficult to clean than mildew because it can get beneath surfaces. You should scrub the area with bleach and water. Mattresses, rugs, or curtains should be washed in detergent and left to dry in the sun. If needed, remove moldy textiles and wall coverings altogether and dispose of them. You may even need to remove parts of your drywall. 

Removing mildew is usually as simple as scrubbing the affected area with bleach and water. For a more natural approach, you can use lemon juice and salt. You should also clean the surrounding areas to make sure you have caught all of it.

Once you have removed your mold or mildew, you can spray the area with an antimicrobial treatment to prevent it from growing back. You should make sure the area is properly dried before you start using it again. You may need to apply sealant or paint to finish surfaces properly.

In some situations, it might be better to seek professional help, especially if mold has penetrated your walls or floors to a significant extent. You may also wish to get external help if you suffer from health problems that could be exacerbated by the mold. 

How to prevent mold and mildew

It’s impossible to stop mold and mildew spores from getting into your home entirely, but there are lots of simple actions you can take to prevent them from causing problems in your home.

Because both mold and mildew prefer damp conditions, the key thing to prevent both of them from growing is to keep your home dry. This may involve:

  • Turning on fans when cooking or using the bathroom
  • Opening windows regularly for natural ventilation
  • Allowing for airflow in little-used spaces like attics and basements
  • Using chemical or mechanical dehumidifiers
  • Keeping gutters clean and clear
  • Keeping vents for heating or air conditioning clean and clear
  • Drying clothes outside or in a drying machine
  • Cleaning up spills and fixing leaks quickly
  • Making sure windows are properly sealed so rain isn’t allowed in

Additionally, you could:

  • Paint surfaces with a mildewcide, a treatment that stops mildew from growing on surfaces
  • Use an air filter to remove spores from your home
  • Use air conditioning to keep your home cool and dry
  • Dust and vacuum to remove the dirt that can feed mold and mildew
  • Air out your clothes regularly and make sure they are fully dry before they go in the closet
  • Let sunlight into your home

To make sure your home’s HVAC systems are functioning properly, you could consider taking out a home warranty. A home warranty covers appliances and systems in your home and will send someone out to repair them if they malfunction. Check out our list of the best home warranty services.

Although most home warranties don’t cover mold damage, keeping your home properly heated and ventilated will help prevent mold and mildew from growing inside. Two of the top home warranty providers are Choice Home Warranty and Select Home Warranty. Both warranties are affordable and can save you from unexpected costs if you need to repair mold or mildew damage. 


Mold and mildew are common problems, but you can prevent them by keeping your home dry and in good condition. If they do occur, it’s best to remove them quickly so they don’t spread or cause health problems for you or your family.

Sometimes, it can be difficult to remove mold from your home. For this reason, changing your behavior, investing in good HVAC systems, and maintaining them properly can make a big difference in reducing the chances of mold or mildew growing. 

Catherine Miller
Catherine Miller is a lead member of personal finance and pension innovator Maji, where’s she’s responsible for content creation and running Maji’s personal finance masterclass. Miller also holds degrees in English and education, and worked as a teacher before moving into writing about finance for Top10.com. Today, she combines aspects of education and personal finance to help readers make better decisions in finance and beyond.