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White Mold: How to Identify, Remove, and Prevent It

White Mold: How to Identify, Remove, and Prevent It

Every homeowner dreads finding mold in their home. It smells bad, causes health problems, looks unsightly, and damages everything from structures to clothing. Some mold is even toxic.

If you see white mold somewhere in your home, you should take action quickly. Mold spreads via spores and can take up residence throughout your home if you don’t confront the problem immediately.

Read our guide to learn how to identify white mold, what’s required to remove it, how much professional mold removal costs, and what you can do to prevent it from coming back.

What Is White Mold?

White mold is more of a loose term to describe the appearance of a few different types of mold. It’s not a specific type of mold. In fact, many different mold species are white at some point in their development.

What is White Mold graphic featuring penicillium growing on an orange displayed on a computer screen alongside a description answering the question

Some mold species have no pigmentation at all, but appear white simply because of the surface or material they are developing on.

The three mold species most commonly referred to as white mold are:

  • Penicillium
  • Aspergillus
  • Cladosporium

These mold species are all fast-growing and have a white color in the beginning of their development process. White mold looks powdery, as though it’s been dusted onto the surface of wherever it’s growing.

It shows up best on dark materials and surfaces and is hard to see on lighter or white surfaces. It usually forms in loose, irregular-shaped circles.

White Mold vs Mildew

Information online is conflicting here, but biologically, mildew is the same thing as white mold. It’s a fungus with a flat growing habit and appears powdery with a gray or white color.

White Mold

White mold growing on a wood panel

Image Source:

Typically, mold is described as being green, orange, or black. Mildew is described as being white. People often confuse white mold with efflorescence.

If you have soft water with high sodium content, or if saltwater has been on a surface and then evaporated, efflorescence is the white, fluffy material that is left behind.

It’s the actual salt deposit that is left behind when the water evaporates. Sometimes, efflorescence is referred to as “salt-petering.”

Not White Mold 

Efflorescence aka not white mold

Image Source: Wikimedia Commons

As you can see, white mold looks very similar to other types of mold. While you may not be able to spot the difference, a trained professional can.

That’s why we always suggest calling one before the problem gets worse (more on that later).

Is White Mold Dangerous?

All mold is dangerous at some level. Many people have allergies to different types of mold and fungus. Exposure to white mold can cause symptoms, including:

  • Allergic reactions
  • Respiratory infections
  • Eye irritation
  • Dizziness
  • Nausea
  • Headaches

Some, but not all, white mold contains compounds called mycotoxins. Mycotoxins are chemicals created by certain types of fungi that are powerful enough to kill humans and animals.

Without having a mold test done, it’s impossible to know whether the white mold you’re dealing with is toxic or not. It’s better to err on the side of caution and assume it is. 

Two known white mold species have certain strains capable of producing mycotoxins and neurotoxins: Penicillium and Aspergillus.

Some Is, Some Isn’t

A close up view of a man at work in full PPE (personal protective equipment), used to protect from airborne mold spores (aspergillus) during a home assessment.


Not all Penicillium and Aspergillus strains produce toxic compounds. Typically, by the time the mold is developed enough to begin producing toxic spores, it will no longer appear white.

White mold can be dangerous to more than just your health. Mold feeds off organic matter like wood and cellulose, so mold that affects your home structure can result in weakened materials that could collapse. 

Whether or not you suspect the white mold in your home is toxic, it’s essential to get it removed as quickly as possible. This ensures your home’s structural integrity isn’t compromised.

Keep yourself, family members, and pets away from affected areas until you can have a professional come out to assess the problem.

White Mold Mitigation: DIY vs Professional

The white mold in your home could be toxic. Even if it’s not deadly, you could inhale spores that cause respiratory distress and infections. Your eyes, nose, and mouth can be affected.

You may develop headaches and nausea from exposure to white mold. For these reasons, it’s not a good idea to remove white mold on your own, even with protective equipment.

When to Call a Pro

White mold disinfectant spray. Mould and Mildew Remover, Killer and Cleaner Concentrate Spray. Removing black stains caused by mould and fungus


Instead, call a professional for mold removal. In truth, professionals don’t actually “remove” mold. The service is called mold remediation.

Mold remediation professionals are trained and equipped to deal with potentially toxic mold. During this process, they use a mix of powerful cleaning solutions and tools.

The goal is to strip the existing mold away. Sometimes, they will apply a coat of sealant over treated areas to prevent mold from coming back.

The White Mold Mitigation Process

When you call a professional for mold remediation services, you can expect a few basic steps to occur. We’ve listed them below.  

  1. Assess and Inspect. Professionals will arrive to inspect your home for signs of mold that are both visible and hidden. They use special equipment like thermal cameras to find leaks and hidden water sources that could contribute to mold growth in areas out of sight.
  2. Stop the Spread. Next, the crew will employ measures to stop the mold from spreading any further in the home. Fans, air conditioning, and heating systems will be turned off. Negative air chambers, physical barriers, and negative air pressure are all conventional mold containment techniques. 
  3. Activate Air Scrubbers. This equipment powerfully pulls the air in your home through a highly specialized filtration system to remove mold spores. HEPA vacuums will also be used to suck any mold spores up and prevent them from recolonizing the mold.
  4. Mold Removal. Depending on the amount of mold in your home, the crew will use antifungal and antimicrobial cleaning solutions to treat any spot with mold. The areas are then deep-cleaned to ensure no spores are left behind. Any porous materials, like carpets, drywall, rugs, and clothing that are affected by mold may need to be disposed of. 
  5. Cleanup and Restoration. Non-porous items and others that can be cleaned satisfactorily will be scrubbed and cleaned. They may be heat-treated and deodorized as well. Any home structural materials that were removed will be replaced. Walls may be painted, and new carpeting or flooring is installed. 

Without the specialized equipment that professionals use, a homeowner can’t do as thorough of a job cleaning up and removing mold.

Let the professionals come in and take care of any white mold problem you have.  After all, they have the tools, know-how, and insurance to cover it all.

Professional Mold Removal Cost

Sad man looking at his wallet with money dollar banknotes flying out away after not calling a pro to mitigate his white mold problem


Mold removal may not cost you any money out of pocket. That is, if the mold is directly caused by flooding and you have flood insurance.

Be sure to ask your insurance provider about mold removal coverage after a flood. Overall, most people end up paying about $1,140 for mold removal or remediation.

Your cost could be as low as $60 for a very small area. It could be as high as $4,000 for a large area or serious mold problem.

If your mold professional charges by the hour, you can expect to pay $40/hour up to about $80/hour.

How to Prevent White Mold

Once you’ve had a professional remove white mold from your home, the last thing you want is to deal with the problem all over again. Preventing white mold from coming back is relatively simple.

There are two crucial things you can do to ensure white mold doesn’t have its preferred environment inside your home.

Keep the Humidity Down

Selective focus on water condensation on window glass. Humidity in the house. Home moisture to keep White Mold levels to a minimum


White mold loves high humidity. If you keep the relative humidity in your house below 60%, there’s not enough moisture in the air to accommodate white mold (and other types of mold).

The good news is that your air conditioning system pulls moisture from the air as it runs anyway. You probably have an air conditioner large enough to cool your entire home.

So just keeping the A/C running keeps humidity levels down in your home. If you live in an older home that has a humidistat, make sure to turn it on.

This pulls moisture out of the air, just like an air conditioner would. Never run your air conditioner while your windows are open.

The warmer air from outside mixing with the colder air inside creates high humidity conditions. It’s really simple, but you have to remain dedicated to this.

Repair Leaks Immediately

Young Woman Standing With Worker Collecting Water In Bucket From Ceiling In House


Leaks don’t just raise your water bill and cause water damage. They also create a breeding ground for mold and fungus. As soon as you notice a leak, however small, keep the area dry while you contact a professional to fix it.

Large leaks or flooding will require an emergency approach. Mold will start to form in about 24 hours, so you need professionals with large air movers and drying equipment right away.

Let Professionals Handle White Mold

Two mold remediation professionals standing back to back with arms crossed preparing to handle a white mold outbreak


When you find evidence of white mold in your home, you may be tempted to grab some bleach and clean it up yourself. The potential for health problems and even death make DIY mold removal too much of a risk.

Rely on professionals with the proper safety gear and heavy-duty equipment. Their powerful air filters, vacuums, cleaning solutions, and equipment to create negative air pressure.

The goal is to eradicate your white mold problem quickly without any risk to themselves or you and your family. Don’t assume that white mold is harmless. Treat it as though it may be toxic – it may be.

And keep everyone away from the affected areas until it is professionally removed. Afterward, keep the humidity low and stay vigilant to look for signs of its resurgence.