How To Get Rid of Musty Smell in Basement

While you may think that “musty” is just how basements smell, it really shouldn’t be.

Not only does a musty smell in the basement make it an unpleasant place to spend time (wasting valuable space in your home) it can actually be a symptom of some serious issues which you should be addressing.

Understanding the Musty Smell

Basements often do smell different to the rest of your home.

They’re below ground and the windows and doors are often left shut for weeks or months at a time meaning that a certain ‘stale’ atmosphere is generally to be expected, especially if you’re only making use of yours as storage.

There’s a difference between ‘stale’ and musty basement smells though. If your basement smells damp and earthy and particularly if the smell doesn’t clear when you let the air flow through for a while, you have a musty basement.

While it’s hard to fully explain the difference in the smells in writing, you will certainly know a musty smell when you smell it.

What Causes A Musty Smell?

Musty odors are usually the result of damp conditions and high humidity combined with poor ventilation. They’re often the combination of stagnant water and the mold and mildew that breeds around it.

Why Should I Worry?

Detecting a musty smell in your basement should set alarm bells ringing- mold can ruin your stuff and cause some serious health problems and if there’s dampness in there causing the mold, it must be coming from somewhere and could be symptom of impending structural issues.

If you do detect a musty odor in your basement, it’s important to work out what is causing it and address the core issue before it gets worse.

Identifying the Causes of Musty Smells

While the root cause of a musty basement smell is usually water in some form, there are a few different forms this can take. If you find that unpleasant earthy odor emanating from your basement, check for:

Moisture And Humidity

These are the primary contributors to musty smells in the basement. Moisture and humid air provide great breeding conditions for mold and mildew and when combined with poor ventilation, smells are bound to follow.

Even if there is no mold visible, stagnant water attracts bacteria and can cause smells of its own.

While you could use a hygrometer to measure just how humid a space is, it’s often possible to feel it as you enter the room. You should also check for condensation forming on your basement walls.

Mold and Mildew

When it comes to musty basement smells, molds and mildews are the most visible causes. They love to hide in dark, dank spaces and will absolutely ruin whatever they grow on, especially paper and cloth- the things we’re most likely to store in our basements.

Not only are they bad for your stuff, they can wreak havoc with your health too. Molds release spores and those can cause very, very serious respiratory problems, especially with prolonged exposure.

Check for black spots and to see if the smell gets stronger on certain objects.

Poor Ventilation

In the rest of your home, you can expect a decent level of air-flow. Windows and doors open and close and vents, air conditioning and heating ensure that air moves around fairly freely through the day.

This is often not the case with a basement space. This allows musty (or any other) smells to build up over time and make them stronger.

Not only will the odors be trapped in a poorly ventilated space, a lack of airflow means that problems with moisture, humidity and dampness are prolonged too. As air flows over a surface, it takes a little evaporated moisture with it. Cut down this flow and you cut down the evaporation effect too.

Leaks and Water Intrusion

As musty smells emanate from damp conditions, it should be no surprise that water in your basement can be a key cause of those malodorous odors.

There are two major sources of water that you should be on the look out for while investigating a musty smell in the basement:

  • Leaks: a dripping pipe can often go unnoticed, leaking water into your basement which, over time, will cause all kinds of serious problems. Checking your plumbing regularly is a good idea but especially if you detect a musty smell.
  • Water Intrusion: groundwater can find all kinds of ways through your basement walls and floors. Check for cracks, along joints, beside windows and across ceilings for signs that water is getting in from outside.
Other Factors

Of course, these are just the biggest causes and the source of your musty smell might be something else entirely. If none of the above seem to fit your particular circumstances, it’s worth checking:

  • Carpets: carpets can act as sponges for smells. If they’ve previously gotten damp, the fibers can often trap the smell long after they’ve fully dried. They also provide lots of nooks and crannies for spores to get a hold.
  • Stored Objects: sometimes that old chair that you can’t bring yourself to throw out or the bags of bedding simply need a clean.
  • Lack of Cleaning: your basement is probably pretty low on your housework list. Sometimes bad smells have simply built up over time and a proper spring clean will get rid of them.

DIY Solutions

Once you’ve discovered the source of the smell, it’s time to deal with the cause. There are few things you can do for yourself and others which you should consult a professional for.

  • Improving Ventilation: Open the doors and windows and let air circulate through to clear the smell from your basement.
  • Dehumidifiers: If humidity is an issue in your basement, plug-in dehumidifiers will help keep it under control.
  • Natural Absorbents: Tubs of baking soda, activated charcoal or silica gel all attract and bind unpleasant odors from the air.
  • Cleaning and Decluttering: Not only will vacuuming and cleaning help remove any spores, moving things around will break up any odor-traps that have formed between the boxes.
  • Essential Oils and Air fresheners: Oils like lemongrass, lavender and lemon can help remove unpleasant smells from the air without simply masking them. Peppermint is also good and has the added bonus of repelling mice and spiders too!

Professional Solutions

Of course, sometimes the root cause of your basement smells is something a bit more serious. Various professionals are just a phone call away if you think you need them.


If you suspect that there are waterproofing issues in your basement, this is nearly always a job for the pros. They can help you with (amongst other things):

Mold Remediation

If you discover mold in your basement that’s not easily dealt with by throwing out an old blanket or two, you probably want to get the pros in. Mold can present some really serious risks to your health so it’s usually best to leave dealing with it to those who know what they’re doing.

Structural Repairs

Sometimes things have gone too far and structural damage has occurred to your basement walls. As the foundation for the rest of your home, this will need dealing with immediately and will require professional intervention

Professional Ventilation Systems

From the humble vent, through ceiling fans and all the way up to state-of-the-art pumped ventilation systems a professional installation can ensure that air flows freely through your basement, taking those unpleasant smells with it as it goes.

Preventative Measures To Keep Your Basement Smell Free

Once you’ve dealt with any musty odor in your basement, you’ll want to keep it smelling fresh. These tips are also great to avoid smells from forming in the first place:

  • Keep up the maintenance: Basement waterproofing and plumbing require a close eye on them. Look for signs that things might be starting to fail and address them before they become a problem.
  • Humidity Control: Using a dehumidifier in your basement space will keep moisture levels in the air regulated and make your home a hostile environment for molds and mildew while boosting your comfort.
  • Ventilation: Regularly open doors and windows, turn on fans and ensure that air is flowing through your basement whenever possible.
  • Material Choices: If you’re rejuvenating your basement into an extra room, or even if you’re just picking new boxes to use for storage, make sure that the materials you choose are mold resistant.

While many of us have gotten so used to the odors emanating from our foundations that we simply refer to them as “basement smell”, ignoring those earthy aromas is not the way to go.

With a little investigation and effort, you can turn your basement from a dark, damp pit of must into a great livable space that smells as good as the rest of your home.