How to Get Rid of Musty Smell in a Basement

Simple and Effective Tips for Removing Basement Odors

If you’re wondering how to get rid of a musty smell in a basement, you’re not alone, especially here in Ohio. In places like Dayton and Cincinnati, humid summers and sudden weather shifts often lead to basement wetness, creating the perfect breeding ground for mold and mildew.

Recent flooding and high humidity can increase musty odors. These smells are not just unpleasant; musty odors can even migrate to upper floors, affecting the air quality throughout the home, often signaling a more serious problem.

The key is finding and fixing the source. You can stop the smell and keep your basement clean and comfortable with proper ventilation, moisture control, and routine maintenance.

Identifying the Source of Basement Odors

Musty basement odors usually point to underlying issues like water leaks, high humidity, or poor ventilation, which encourage bacteria, mold and mildew growth.

In Ohio, you may notice these smells often become more noticeable after heavy rain or snowmelt, when moisture levels spike.

• See: What Time of Year Does Mold Grow

Start by inspecting the basement for apparent signs of trouble: cracks in the foundation, damp walls, or pooling water. Check around the sump pump and drain hose to ensure they’re working correctly and not contributing to excess moisture.

Look behind furniture and cardboard boxes for water-related issues if your basement is furnished or used for storage.

Also, since mold feeds on organic material, check the boxes and furniture for wetness. Dust and dirt are organic, too, so regular cleaning and decluttering are important.

Carpet, drywall, and wood can hold onto odors even after water problems are resolved. In cases of severe water damage, removing and replacing these materials may be necessary.

Watch for clues like black spots, white powdery residue, or a persistent earthy odor.

If odors persist after clean-up and repairs, it could point to hidden issues like clogged drains, sewer gas leaks, or decaying organic material behind walls or under floors. A thorough inspection may be needed to uncover and resolve the source.

Why Does My House Smell Musty, But I Don’t See Mold?
Mold isn’t always visible. A musty smell without visible mold often means dampness is trapped where you can’t see it, behind drywall, under carpets, or inside insulation.

Also, high humidity, poor ventilation, or past water damage can leave behind lingering odors even if surfaces appear dry. Addressing the underlying problem is critical for getting rid of musty smells. Have more strange smells in your home?

• See, What is that Smell? How to Remove Unwanted Smells in Your Home

Remove and Prevent Excess Moisture

Excessive moisture is the root cause of most musty basement smells. Basements are naturally more damp than upper levels and often lack proper ventilation and air movement. 

In many older Ohio homes, even minor issues can escalate if left unchecked. That’s why preventing moisture and acting early are essential to avoiding musty odors and long-term damage.

Start With a Dehumidifier

Using a dehumidifier to help maintain basement relative humidity between 40–55% helps create less favorable conditions for mold and mildew. Track levels with a digital hygrometer (available at most hardware stores for around $15 to $20+). Be sure to regularly empty and clean the unit to prevent it from making the odors worse.

Will a Dehumidifier Help With a Musty Smell in the Basement?
Yes. Dehumidifiers are essential for controlling humidity levels. They extract excess moisture from the air to prevent mold growth and unpleasant odors. Combined with ventilation and moisture control, it helps clear out stale odors and keeps your space dry and comfortable.

Seal Water Leaks and Watch for Condensation

Even small cracks in foundation walls or around pipe entry points can let in water, especially during Ohio’s rainy seasons. Apply waterproof sealant where needed and check areas like window wells regularly. Catching and sealing leaks early prevents water buildup and odor recurrence.

Not all moisture comes from leaks. In humid conditions, condensation can form on cold surfaces like pipes, concrete walls, or uninsulated floors. This hidden dampness can lead to the same musty odors. Wrap cold pipes, insulate basement walls, and ensure airflow to help surfaces stay dry.

Basement Walls and Chronic Moisture 

If your basement still feels damp despite your efforts, you may be dealing with ongoing water vapor intrusion. Unsealed masonry and porous concrete are typical in older homes and allow vapor to pass through, even without visible leaks.

Basement waterproofing, including sealing walls and applying vapor barriers, offers a long-term solution and helps prevent moisture problems that, if left unchecked, could lead to structural damage. 

Improve Air Circulation

Good airflow reduces dampness and keeps musty smells at bay. Use fans or install ventilation systems to circulate fresh air, especially in basements with small windows. Exhaust fans can also help pull humid air out, minimizing condensation.

Local Tip:
Exterior drainage plays a significant role in indoor moisture. Many homes in the Dayton and Cincinnati areas have short downspouts that discharge water near the foundation. Extend the downspouts several feet away to protect your basement. Also, inspect your sump pump regularly, particularly before spring storms.

• Did you know mold can grow in your HVAC too?

Remove Mold and Mildew

To fully eliminate musty smells, you must remove the mold and mildew that causes them. These organisms not only smell unpleasant, but they can also damage surfaces and affect indoor air quality over time.

You can tackle the issue for small areas (under 10 square feet) yourself.

Apply a Cleaning Solution:
To kill mold spores, use any household cleaning product. (We do NOT recommend bleach.) Spray the affected area generously and let it sit for several minutes.

Always use caution. When cleaning, wear gloves, goggles, and a mask to avoid exposure to spores and cleaning chemicals. Never mix household chemicals since this can create dangerous fumes.

Scrub the Area:
Use a soft brush or cloth to scrub the surface. Be sure to reach into corners and crevices where mold tends to hide.

Repeat and Dry:
Reapply the cleaning solution to ensure any remaining spores are treated. Once clean, be sure to dry the area thoroughly.

Preventive Measures:
Consider applying a mold-resistant paint or coating to help stop mold from coming back. These products form a barrier that helps protect surfaces from future growth.

If the smell persists or covers a large area, it’s best to call in professionals. Hidden mold behind walls or beneath flooring may require specialized tools and remediation techniques.

Does Mildew Smell Worse Than Mold?
Mildew often has a lighter, mustier smell, while mold produces a stronger, more pungent odor. Both are signs of dampness and should be addressed quickly. Smell alone doesn’t determine severity.

The Bleach Myth

It’s a common myth that household products like bleach or baking soda can eliminate mold. While bleach might lighten surface stains on hard materials, it doesn’t reach the root of the problem, especially on porous surfaces like drywall or wood and can sometimes exacerbate the problem.

A Note on Natural Odor Absorbers

Products like baking soda, activated charcoal, and white vinegar can absorb and neutralize some odors. However, they do not kill mold or bacteria and will not solve the main cause of the odors. If wetness is present, these solutions are just temporary.

Professional Help for Basement Mold Removal and Water Damage

If you’re dealing with persistent odor problems, visible mold growth or a damp basement, it’s time to call in the experts.

PuroClean Emergency Services serves the Dayton and Cincinnati areas with trusted, local mold remediation and water damage solutions.

Our team understands the common challenges in Ohio homes, from older foundations to frequent humidity issues.

For safe, thorough help with unwanted smells in your basement, trust the professionals at PuroClean. We’re available 24/7 to restore your basement and protect your home’s air quality.

Call PuroClean Emergency Services Today:
Dayton, OH – 937-401-9700
Cincinnati, OH – 513-897-8990