My House Smells Musty But There Is No Mold – Causes and Remedies

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Sometimes, when you open your front door after a long day at work or a weekend away, the first thing that greets you is a musty smell that has infiltrated your entire home, and nothing can shield you from the discomfort. The stale, stuffy, damp smell is often an indication that mold is growing somewhere in your house—but that is not always the case. Sometimes your house might just have that musty smell with no mold.

Musty Smell versus Moldy Smell

The two are almost indistinguishable, yet both are an indication of the presence of fungi growth in your houses and living areas—either mold or mildew. Mildew is a downy surface growth that is often found on the surface of vegetables, fruits, or plant materials. It is thin and powdery. Mold, on the other hand, is thick and penetrates deeper into the surface upon which it has grown. Often, mold grows on walls, floors, clothing, cardboard, books, or plants. Both mold and mildew grow in the presence of moisture, oxygen, and darkness. There are various causes for a house’s musty smell. Make sure to take care of musty smells before the mold forms.

If mold is not the cause of the musty smells in your house, mildew is likely the cause. The distinction arises from the strength of the odors. A moldy smell is often stronger compared to a musty odor. However, if not dealt with, mildew will eventually result in the growth of mold, and the musty smell will get stronger. The mold and mildew release microbial compounds that cause the odor. To eradicate the irritating smell and prevent further damage and discomfort from the fungal growth, it is crucial to act quickly—identify the cause and deal with it swiftly.

What are the Main Sources of Musty Smells?

Water leaks

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Water leaks can happen in several ways. If it is the rainy season, rainwater may have entered your house undetected. The roof might be leaking, causing water to soak through the ceiling. Also, rain can seep into the house and into the basement, through the walls, and other hidden spaces, causing mildew to grow.

Water leaks can also be a result of a faulty plumbing system. The pipes might have started to leak, or the valves might become loose and cause water to leak. Drain hoses are also serious culprits as, over time, they trap and hold water—creating suitable conditions for mildew and mold to grow. Double check the mold and mildew near your washing machine, building materials, and clothes as this might cause structural damage and health problems.


If ventilation is poor and affecting the house’s air supply, a cold window in a warm room results in condensation. The warmth and moisture that results creates a good environment for mildew and fungi to grow. Also, if it rains or if you fail to dry your windows properly after cleaning them, mildew may grow on the edges. This is particularly prevalent on wooden window frames. The furnishings in the living room should be free from mildewy and musty smells. Improving air quality is the best solution if a house smells musty. Double check the air space and around window to prevent musty odors in the home. The air quality of a home can be harmed by musty odors.

Laundry drains

Your laundry area, if not cleaned and dried properly after doing your laundry, can be a good place for the growth of mildew and mold. Also, front load washers are good at retaining water in its nooks and crannies. This also can result in fungal growth and, consequently, the musty smell. The musty odor will come back if owners don’t follow mold testing and carpet cleaning guidelines including deep-cleaning compounds.

The best thing you can do is leave your washer’s doors open, check the seals and other places where moisture can hide and clean them periodically.

Unaddressed water damage

Water damage should be addressed immediately to avoid compromising the structural integrity of the house and to prevent the growth of mold. If water damage is not addressed, the retained moisture will allow mildew and mold to thrive.

Sometimes the water damage may go undetected, especially if water has seeped into hidden surfaces such as behind wallpaper, behind sheetrock, or under the carpet or rugs.


Besides improving the quality of the air in a house, plants help boost your home’s aesthetics. However, plants can also cause musty odors. This often arises when you overwater your plants, or when you do not remove debris and dead leaves. The debris and dead leaves can trap moisture and heat, resulting in mold growth.

The Air Conditioning System

The AC system is essential for maintaining proper air flow in the house. However, the humid air and warmth it generates can lead to the growth of mildew inside the AC, and lead to mold problem. This results in the musty smell being spread throughout the house as the AC circulates air. The result is mustiness in the whole home, which can lead to serious health issues. Cleaning mold is the best answer to rule out mildew smell and bad odor.

One way to fix this is to leave your AC on at all times to maintain good air flow and prevent water from settling by keeping the system dry.

The fridge and freezer

The nooks and crannies of your freezer and fridge doors are perfect surfaces for mold and mildew to grow. If left uncleaned for a long time, the odor will spread throughout the house. Just clean the seals regularly and there will be no problem!.

Garbage cans

Garbage cans are, unsurprisingly, a common cause of bad smells in the house. Many people often leave the trashcan in the house to overfill before emptying it. Given that we dump food and other substances that easily decompose in these bins, mold can easily grow on them within a few days if not emptied.

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Improperly stored/disposed of food and beverages

If you leave your food on a table for several days, or if you do not dump the beverage container in the bin, the residual compost results in a musty smell that spreads fast in the house.

The bathroom

These smells are very common in the bathroom due to its high moisture levels. The musty smell can originate from water damage, the floor, curtains, mats—any fabric or surface. If not properly cleaned and maintained, the musty smell from the bathroom will spread to the rest of the house.

The basement

In most homes, the basement is not a frequently visited place. The dark, humid, and moist conditions therein mean that it is only left to serve as a storage room or a workshop. Often, conditions in the basement are conducive for mildew and mold to grow. If unaddressed, the growth can spread rapidly, enhancing and spreading the musty smell to the rest of the house.

The easiest thing to do in the basement is increase air flow and/or get a dehumidifier to keep the moisture level down.


Sometimes the season can lead to the musty smell in your house. During the winter, the air is cold and thus does not hold much moisture. However, when the warm summer season sets in, the high temperatures increase the humidity levels in the air. The combination of warmth and moisture create the perfect conditions for the growth of mold and mildew in your home. If the ventilation and air conditioning are not effective, eventually your home will develop the musty smell.

Why You Should Get Rid of The Musty Smell Fast

If the uninviting and unpleasant musty smell is not enough reason for you to deal with the root cause, here are other reasons why you should act fast.

  • To protect your health

Mold and mildew produce irritants, allergens, and in some instances, toxic substances that can be harmful to your health when inhaled. These result in respiratory reactions often in the form of sneezing or having a running nose. Allergic reactions, headaches, dizziness, fatigue, nausea, red eyes, and skin rashes may also occur. It can be particularly dangerous for people with asthma.

  • To protect the quality of your home

As mentioned, the presence of mold or mildew may indicate that your house has water damage. Water damage, if unaddressed, compromises the integrity of the structures in your home and thus lowers its value. Finding the cause of the musty smell and avoiding any further damage to your house is the best way to maintainits value and improve air quality all year round.

  • To prevent the smell from getting stronger

Naturally, no one would want to stay in a house that smells; it is uncomfortable and uninviting. Dealing with the musty smells fast will help in contain the smell in the long run, thus preventing it from getting stronger and spreading further in the house.

How To Remove The Musty Smell From Your House

A musty smell is an indication that mildew or mold is growing somewhere in your house. Therefore, the first step toward eradicating the smell is identifying the location of the fungal growth. A musty smell does not necessarily mean that the mildew or mold has grown to a wide area, and so it is important to be thorough and swift in eradicating even the smallest growth since covering it up will only make the growth expand further, and the musty smell will get stronger.

Here are the actions you should take.

  • Clean the area with mold or mildew thoroughly

Deep cleaning areas affected with mold or mildew is essential to prevent the fungi from spreading and eradicate the resulting musty smell. Given that mildew is thin and easy to remove, normal cleaning methods should get the job done. A common and effective cleaning method involves scrubbing the mildew-covered surface with an abrasive sponge soaked in hot water and dipped in baking soda. However, you can also use bleach to be even more thorough. If you have mold, you should be careful as you scrub the surface to eliminate mold effectively.

After cleaning, ensure you dry the surfaces completely. Moisture is one of the key ingredients that facilitate the growth of mold and mildew. If drying is not done properly, you risk the fungal growth reemerging.

If the musty smell is coming from your trash can or rotten food, dispose of the trash and clean the surfaces thoroughly. If the smell is from damp clothes, soak them in cleaning detergent, clean them thoroughly, and them dry them completely in an open place.

  • Improve the flow of fresh air in the house

Improve air circulation in your house by opening the doors and windows to let in fresh air and let out the musty smell. Ensure the blinds and the curtains are opened wide enough to let in as much fresh air as possible. If the smell originated from cupboards or other closed surfaces, ensure that the doors to those spaces are also wide open to let the foul smell out and allow clean air in.

Turning on all the fans in the house will help encourage airflow and eliminate the musty smell faster. These can be particularly helpful in rooms with poor ventilation, such as the basement.

  • Fix water leaks

If you have any leaking pipes or water inlets that dampen certain sections of your house, have those fixed fast. If not, the problem will recur. Also, adopt a habit of regularly inspecting your plumbing system for leaks. Inspecting the roof is also important, especially during the rainy season. These inspections are helpful in quickly identifying the problem and fixing it before it becomes worse.

  • Use a dehumidifier

Limiting the humidity level in your home, especially during the summer, will help prevent mildew or mold growth, as well as the musty smell. Other than limiting the moisture levels in the air, humidifiers also help keep your surfaces dry and food fresh for longer periods of time. Humidity levels in your home should be maintained below 60% at all times.

  • Odor removal

There are several natural methods for removing odor. You can boil lemon peels in a pot, and, once it produces a fragrant smell, move the pot to the source of the musty smell. Leave the pot open for the fragrance to fill up the room. This will eliminate the bad odor by acting as a natural air freshener. Activated charcoal and baking soda have also proven effective at absorbing bad odor. They should, however, be replaced every two weeks.

  • Replace your air filters

If you get home and find a musty smell trapped inside, chances are that the air filters in your HVACs have grown old and ineffective. In addition to improving the quality of air in the house, replacing the filters will help prevent the growth of mildew and mold.

Use Air Purifiers to Eliminate Musty Smell

air purifier
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In addition to the methods above, air purification is one of the most effective methods of dealing with a musty smell in your house. The various air purifiers available work differently. Some emit negative ions, causing mold particles to stick to it. However, if the particles are not cleaned, they can be picked up off the ground again. Others purify the air by emitting ozone, which kills the spores. While effective, the ozone can be harmful to people and animals in large quantities.

HEPA filtration has proven to be the most effective air purifier. It pulls air into the unit and through its filters before releasing clean air out. Most filters come with a carbon pre-filter, which helps eliminate bad odor.

Pros of HEPA Filtration

The HEPA filters are the most effective filters for particle removal, and thus are best suited to eliminate the musty odor from your house. The mold spores that give rise to the musty smell are between 1 and 5 microns in size—smaller than a grain of table salt. The HEPA filters can filter these out. Furthermore, the HEPA filters have been proven to eliminate up to 99.97% of particles. They can filter out particles as small as 0.03 microns! Also, unlike other filters that simply emit negative ions that cause particles to fall, HEPA filters render the mold spores inert. The sterile environment makes the spores sterile and unable to survive.

To maintain the effectiveness of the air purifiers, it is crucial to replace the filters often. There are various air purifier brands to choose from, and so it is important to select the best air purifiers for the most effective results.


Dealing with a musty odor in your house swiftly is important to protect your health and restore the comfort of your home. If you find yourself with a musty-smelling house, be quick to identify the source of the odor and employ counter interventions immediately. It is best to employ a combination of the mitigative measures highlighted here, such as the use of air purifiers. Most importantly, regularly cleaning all surfaces and maintaining good hygienic standards go a long way in preventing the foul musty odor from developing in your house.

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