Figuring out how to clean mold off walls is one of the oldest and most common questions of anyone who lives in a building in a wet or humid climate. According to many studies, between 40% and 50% of homes in the United States have mold at some point! That means that at some point, you are likely going to need to know what works to clean mold, and what doesn’t.
We’re here to give you that answer, from professional experience. We’re Cleaner Guys, a certified mold removal company with more than 20 years of experience dealing with molds of all kinds. We know what works and what doesn’t!
Table of Contents
- What is Mold?
- Are You Dealing With Mold or Mildew?
- How to Clean Mold Off Walls – 2 Things That Work and 5 That Don’t
- More Resources
What is Mold?
Mold is a fungus that grows wherever it can find moisture, a food source it can absorb, oxygen, and warmth. This means that mold is most commonly found in areas with high levels of condensation or humidity, or anywhere there is water damage, like a leak or a flood. Learn more about what counts as water damage in this article.
Mold spores are floating around in the air all the time, both inside and outside, just like dust. People don’t usually get sick from the spores floating around in the air because the concentration of spores is too low to cause a reaction in the body. However, wherever mold spores find excess moisture, like from a leak or condensation, they will land and begin to root and grow.
Once mold starts rooting and growing on a surface, it begins releasing its own spores. This greatly increases the concentration of mold spores in the air, which is why people living near mold growth can get mold sickness.
Are You Dealing With Mold or Mildew?
Knowing the difference between mold and mildew is crucial because it completely changes how you clean it. Most molds grow and root deeply into porous organic materials like drywall and wood. But mildew is a shallow-rooting subspecies of mold that prefers to grow on hard, nonporous surfaces, like plastic, ceramic, and tile. This means that while most molds are very difficult to clean, mildew is as easy as scrubbing it away with vinegar or a household cleaner!
So, how do you tell if what you’re dealing with is mold or mildew? Four main characteristics should help you figure it out.
Signs of Mold or Mildew
The first is color. While mold can appear black, grey, green, brown, and occasionally red, mildew usually presents as white in its early stages, and brown or black when it ages.
Second is texture. Mold is typically fuzzy, or sometimes slimy, while mildew is usually described as fine and powdery feeling.
Structure and pattern are a third way to tell mold and mildew apart. Mold grows in clusters of large spots or patches. Mildew’s growth pattern looks like dense clusters of very tiny dots, sometimes so dense they don’t even look like individual dots, particularly in places like shower grout.
Last is location. Mold likes to root deeply, eating its way far into drywall, wood, or whatever organic material it’s feeding on. Mildew, on the other hand, likes to grow on the surface, and can therefore live on impenetrable surfaces, like tile and plastic. That means that if you see dark moldy spots on drywall, wood, or other porous surfaces, it’s probably regular mold growth. But if you see dark spotty growth in your shower, toilet, or on plastic window frames, it’s probably mildew.
To learn more about how to clean mildew, read our detailed article here.
How to Clean Mold Off Walls – 3 Things That Work and 4 That Don’t
Because mold roots so deeply, as we’ve discussed, unfortunately not many things work on it effectively. In fact, many mold cleaning solutions touted by those on the internet who aren’t mold experts do not work! But we here at Cleaner Guys have been successfully cleaning and removing mold for more than 20 years, and we’re here to tell you what works… and what doesn’t.
What Doesn’t Work
Many unprofessional sources on the internet will tell you that bleach, vinegar, and even rubbing alcohol can work to clean mold. We do not recommend any of these solutions. The main problem with them is that none of them are strong enough to penetrate deeply enough to kill all the mold. Mold is quick to spread deep into drywall, and bleach, vinegar, and rubbing alcohol simply don’t penetrate deeply enough to get all of it. Regular cleaning chemicals like Clorox and dish soap, and even natural remedies like witch hazel, don’t penetrate deeply enough either.
In fact, using mixtures of bleach or rubbing alcohol can be downright dangerous! Both emit toxic fumes that can cause dizziness, nausea, and worse. As if that wasn’t enough, bleach is so caustic it usually permanently damages most surfaces. And rubbing alcohol is highly flammable, which means risking a fire hazard while trying to clean mold!
What Does Work
So, if none of the popular “home remedies” for cleaning mold actually work all that well, what does? Thankfully, there is a topical solution that can work well on mold.
Fungicide is the only topical chemical cleaner that we professionally recommend for cleaning mold off walls. However, even fungicide only works in certain circumstances. Our professional advice is that if the mold you can see covers less than a single area of wall that is less than 1 square foot, you can try using a good antimicrobial fungicide on it. When mold growth is this small, it likely hasn’t penetrated or spread very far yet under the surface.
However, if the mold you see covers more than 1 square foot of area, or there are multiple patches of mold, fungicide will probably not work. Mold growth that has spread that far has probably already spread much farther inside the wall, where you can’t see it.
In this case, there is only one mold removal method that will successfully remove 100% of the mold: physical removal of the mold-infested drywall. When mold has spread far, the cheapest and fastest solution is to just get rid of it, then spray the area with a fungicide (to make sure it can’t come back), and then replace it with new drywall.
IMPORTANT NOTE: physical removal of mold-infested materials should not be attempted by an untrained layperson. Stirring up the mold spores without the proper PPE and training can make you very sick. Additionally, it takes professional expertise and professional equipment to ensure that all of the mold is gone before you replace the drywall.
If you have mold that covers more than a 1 square foot area, the only option you can safely pursue is calling a professional mold removal company.
More Resources
We hope you learned something from this article on how to clean mold off walls. Explore our vast archive of information on mold, water damage, fire damage, and more here, or jump to another relevant article below!
Can you paint over mold? Answers from an expert. ➜
What do you do about mold in an apartment? ➜
Is it safe to stay in a house with mold? ➜
If you find yourself in the unfortunate position of needing a mold removal company in Western Washington State, consider Cleaner Guys as a high-quality, well-trusted option. We’re proud to boast award-winning customer service, lower prices than others, and top-notch workmanship! Contact us today through the menu at the top of your screen.
Disclaimer: This article is for informational purposes only. No part of this article is medical or legal advice, and may not be used as such. For all serious medical matters, consult your doctor. For all serious legal matters, consult your legal advisor. This article contains Cleaner Guys’ experience and opinions only.
