Can a Moisture Meter Detect Mold?

No, a moisture meter can’t detect mold directly. But it can help you find areas with higher moisture levels, meaning that mold could develop in those areas if it hasn’t already.

Because of this, a moisture meter can be especially helpful in the process of mold detection or in identifying potential spots where it could grow.

Mold isn’t always immediately visible, since it’s more likely to grow in dark, enclosed spaces or on the hidden sides of walls, floors, ceilings, etc. That’s why any tool that can point you in the right direction will certainly help streamline the process.

So let’s go over exactly how you can use a moisture meter to assist in the detection, elimination, and prevention of mold:

• Recognizing evidence of mold
• What to do about it
• How to prevent it
• How to protect your home

Let’s start by reviewing what to look for.

Recognizing evidence of mold

Mold can be black, green, or white, and it can look fuzzy, slimy, or powdery. If you can already see any of that, that means the mold spores have already been growing for a while.

And even if you can’t see mold at first, there are some visual cues that could indicate its presence, such as:

• Discoloration
• Unexplained water stains
• Condensation
• Peeling paint or wallpaper
• Warping of wood or wood-type products

A musty smell can also be a sign of mold, even if you can’t see any evidence of it yet.

Other signs can take the form of otherwise unexplained health issues, such as:

• Headaches
• Congestion
• Skin irritation
• Allergic reactions¹

But, to be sure that mold is the culprit, you have to be able to find it.

Mold and moisture can be sneaky. You can’t always tell that there are damp spots behind your wall or under your flooring—at least not until it grows into a large enough problem that it becomes visible on an outer surface.

So if you want to seek out these potential problem areas, or at least try to find any mold issues before they get out of hand, a moisture meter can make your search a lot easier.

Using your moisture meter during a search for potential mold

The key is to measure the moisture content in suspect areas. Here’s how to use some visual cues to determine where to take moisture measurements.

To start off, look for any warping, such as on a hardwood floor. If you spot some cupping, bowing, or gapping, use your moisture meter to check the wood’s moisture content. Keep in mind that anything above 19% could grow mold.

Some wood moisture meters can work in relative mode, enabling them to measure moisture in materials like drywall or carpet. You’ll want to take several readings in different places to determine if any areas give higher moisture readings than others.

So if you notice a water stain or peeling paint on the ceiling or wall, put it in relative mode and compare different areas of the wall. This mode won’t give you exact moisture readings, but it will help you identify areas of higher and lower moisture.

If the area with the stain has a significantly higher moisture level, you might be dealing with a current moisture problem and possibly mold.

So, what do you do if you do find mold?

What to do about mold

Mold isn’t something to mess around with. It can mean high moisture levels that can cause wood to rot.

It can also cause health issues, including coughing, sneezing, headaches, rashes, and even fevers.² Some of these molds are allergens like Aspergillus and Cladosporium.³ However, other types pose other dangers. Pathogenic molds like Cryptococcus neoformans and Histoplasma capsulatum can cause infections, and toxigenic molds like Stachybotrys chartarum contain harmful toxins.⁴

Besides causing health problems, mold is also unsightly and is usually interpreted as a lack of care or cleanliness.

No matter what type of mold you’re dealing with, you’ll want to get rid of it as soon as possible. The best thing you can do is stop the cause of the mold and clean and dry out the area where it’s been growing.⁵

As we’ve pointed out, mold can’t grow without moisture. So the next item on the list is to determine how an area got to be higher in moisture than it should be.

Possible causes of unwanted moisture are:

• Previous water damage that didn’t dry completely
• Plumbing leaks
• Inadequate drainage
• Roof damage that allows rainwater to soak into the insulation
• High humidity levels in the room

And at times, the cause could even be the failure of a floor installer to get flooring or subfloor materials to the appropriate moisture level before beginning the installation.

Once you’ve figured out the cause and stopped any moisture problems, you’re ready to deal with the mold.

The U.S. Environmental Protection Agency (EPA) specifies that if a mold issue is less than ten square feet, you, the homeowner, can probably deal with it yourself.⁶

Scrub the area with dish detergent and water while wearing proper protective gear.⁷ The EPA recommends wearing⁸:

• An N-95 respirator
• Gloves
• Goggles

Once the area is clean, wait for that spot to dry before putting back your floorboards or fixing your drywall.

You can help speed up the drying process by exposing wet areas to fans and dehumidifiers.

Once you think it’s dry, check it with a wood moisture meter to confirm that the material meets appropriate moisture levels.

While it’s possible to deal with most mold issues on your own, the EPA recommends reaching out to professional remediation services if the area is larger than ten square feet, or if you’re dealing with contaminated water.⁹

But hopefully, you won’t have to deal with a full-blown mold issue and you can prevent mold growth from becoming a significant problem.

And a moisture meter can help with prevention as well.

How to prevent mold

Preventing mold means preventing moisture from hanging out in areas it shouldn’t.

Just as in mold detection, a moisture meter can help you find those areas early on so you can remedy the situation.

Here are some simple practices to keep in mind:

Make sure rooms have proper airflow and ventilation

Poor ventilation and airflow can cause excess moisture to sit in an area rather than being released outside.

Make sure your HVAC—heating, and ventilation, air conditioning—vents are working well, particularly in areas that get steamy or involve a lot of water use, like a bathroom.

Maintain proper humidity levels

Typically, a room should be somewhere between 30 and 50% relative humidity. Keep the levels consistent as much as possible, especially in a humid climate.

You can do this by:¹⁰

• Using an air conditioner regularly
• Using exhaust fans
• Increasing home ventilation by opening doors and windows

If moisture levels get higher than they should be, you can use a dehumidifier. If you want to increase moisture levels you should use a humidifier.

Clean up water leaks and spills right away

Don’t allow moisture to sit anywhere. Be sure to address the leak or spill, ideally within 24-48 hours, to prevent mold growth.¹¹

You may need to use fans or dehumidifiers to make sure the damp area dries before you move furniture, put floorboards back in place, etc.

Use moisture testing in high-risk areas

A moisture meter is a great way to check areas in your home that are at high risk for moisture problems.

These areas include:

• Bathrooms
• Kitchens
• Unfinished basements
• Attics or crawl spaces

On top of that, you’ll also want to check windows, doors, sinks, and appliances like dishwashers and laundry machines for leaks or condensation.

Though you don’t have to check for moisture every day, it’s important to keep a regular eye on these problem areas, especially when you are aware of leaks or increased indoor humidity. Or, if you live in an area with higher humidity.

The best way to do this is by using a moisture meter.

They can help you spot moisture problems you wouldn’t have noticed with the naked eye. And some meters can get your measurements with the push of a button, making it quicker and easier for you to take more readings.

Pinless meters are very quick and won’t cause any damage to the area, so it’s a great option when you have multiple areas to keep an eye on.

Protect your home from mold

By understanding how to find, remove, and prevent mold, you may not have to deal with it aside from unplanned events like leaks, big spills, or extreme weather.

And by having a pinless moisture meter, though it can’t directly detect mold (or help you remove it) it can identify high moisture levels that could lead to mold growth.

And because preventing mold is much easier than cleaning it, moisture meters will go a long way in helping you keep your home mold-free.

If you’re looking for a reasonably priced and highly accurate moisture meter for this purpose, Bessemeter has you covered.

You can visit our store to see our complete range of meters.

To learn more about our meters and how they can protect your home,

1. “Mold and Health,” US Environmental Protection Agency. (↑)
2. “Mold Allergy,” Mayo Clinic, June 21, 2021; “Mold,” CDC, Sept. 26, 2024; “What Homeowners & Renters Should Know About Mold,” Green Orchard Group, Nov.10, 2022. (↑)
3. “Which Molds Are Dangerous to My Health?” IQ Air, May 8, 2024. (↑)
4. Ibid. (↑)
5. “Mold,” CDC. (↑)
6. “A Brief Guide to Mold, Moisture and Your Home,” US Environmental Protection Agency. (↑)
7. “How to Remove Mold From Wood in 7 Steps,” Green Orchard Group, Feb. 3, 2022. (↑)
8. “A Brief Guide to Mold.” (↑)
9. Ibid. (↑)
10. “Mold,” CDC. (↑)
11. Ibid. (↑)