My basement is dry but still smells musty?

This article discusses how to get rid of the musty smell from basements even when your basement is dry. We first look into the possible sources of musty smell in a dry basement, and how to prevent it in the future as well.

Why does my basement smell musty?

Basements are typically enclosures which are below ground level, and are surrounded by underlying rock and soil. As a result, there is usually low or no source of natural lighting or sunlight.

Furthermore, given their placement, basements can also be prone to leakages and seeps due to groundwater, especially during rainy seasons, or due to leaks in pipes.

These factors altogether create a dark, humid, and cool temperature condition. Under such conditions, the growth of mold and bacterial microorganisms is favoured.

Mold is defined as fungal colonies that grow in the form of multicellular filaments. Most of them are harmless in nature and cause minor allergic reactions other than the odor, but some can have serious implications on health if inhaled.

Where can mold be growing

As we’ve seen so far, mold usually grows in dark and humid places. Furthermore, Mold usually requires a source of nutrition, which it can find in certain objects that are stored in basements.

The possible sources of mold can include:

  • Leaky pipes or seepage
  • Items containing cellulose
  • Faulty air maintaining appliances.
  • Humidity within room

Let us discuss these in more detail.

Leaky pipes or seepages

As mentioned before, basements are particularly prone to leakage or seepage since they are built below ground levels. These give rise to humid conditions that are required for mold to grow and thrive.

If your basement has a bathroom that is used regularly, there can be chances that there is a leak or seepage in the bathroom, due to which mold is growing, leading to the generation of musty odor.

Items containing cellulose

Cellulose is a molecule that is composed of hundreds and thousands of carbon, hydrogen, and oxygen. These molecules are the building blocks of plants and help to keep them rigid.

Certain household products are derived from plants, and contain cellulose. Items such as clothes made out of cotton, beddings and carpets, furniture, paper products and cardboards, etc. are such items that contain cellulose in their structure.

These items provide the optimal nutrition required for mold to proliferate, hence they are prone to mold formation. One can see that clothes stored in dark places during seasons of high humidity usually have mold growth present on them.

Given that basements lack natural sunlight, these items become even more prone to growth of mold and other forms of bacteria, due to which the characteristic musty odor emanates from such objects.

Faulty air maintaining appliances

Certain basements have appliances such as air conditioning units, air purifiers, or HVAC (Heating, Ventilation, Air Conditioning) units in order to regulate the temperature and air quality of the room.

However, these appliances too can become the source of musty odor in your room. In these appliances, the air filters used usually end up trapping dust particles which can also contain mold spores in them.

In humid conditions, especially in air conditioners, due to the buildup of mold spores and prevalence of dark and humid conditions, mold colonies start to form.

As they grow, these appliances start to give out the unpleasant musty odor. The odor becomes even more prominent for old devices or appliances that haven’t been maintained well.

Humidity within room

Basements usually have poor air circulation. As a result, the air gets stale. If one lives in a region with a warm and humid climate, or in some cases, have a central boiler in your basement, the humidity levels can be higher than normal.

In high humidity conditions, mold and bacteria proliferate, and give rise to even more spores. In this process, they also generate the musty odor, hence causing the room to stink.

How to get rid of the musty odor from basements

It is vital to practice habits that would help to prevent the musty smell from forming in basements in the first place. This can be done by the following methods:

  • Improve ventilation
  • Use an air dehumidifier
  • Regularly cleaning the basement
  • Check for leaks and seeps
  • Use an air purifier

Improve ventilation

Opening your doors and windows for some time during the day helps to increase the air exchange rate with the outdoor air. As mentioned earlier, this helps to remove the indoor pollutants as well as the odor, while introducing fresh air.

However, it is important to check the outdoor pollen and mold count, since on days of high concentration levels, the smell will get further exacerbated.

For places which do not have proper sources of natural ventilation, such as basements, HVAC systems are especially helpful. 

However, one should also ensure that the HVAC systems are being maintained on a regular basis, since faulty systems as well as older units may sometimes contribute to the stale air smell.

Use an air dehumidifier

As seen from above, high humidity levels play a major role in the generation of stale air smell indoors. Therefore, it is important to regulate the indoor moisture levels.

This is where air dehumidifiers come in the pictures. These devices, as the name suggests, lower the humidity of the indoor environment, therefore keeping the air dry and hampering the growth of mold.

Some devices come with a monitor that helps you to set the humidity level according to your need. The ideal range of humidity is thirty to fifty percent, as mold growth would not occur, while the air isn’t too dry, which can irritate the respiratory passage.

Regularly cleaning your basement

It is important to keep your house clean, especially surfaces such as beddings, carpets, or places where people usually are present.

Studies have shown that nearly 60% of total dust accumulated in the indoor air originates from outdoors. Within these dust particles, mold spores and other substances can be present, which cause indoor stale odor.

By regularly dusting surfaces and cleaning the basement, there are lesser chances of accumulation of substances that give rise to stale air smell.

Fix leaks and seeps

It is vital to check for any source of leaks or seeps occurring within the basement, as they could cause the problem to spread to other rooms of the house as well.

In such cases, it would be wise to hire a technician who can help fix leaks and seeps, and resolve the issue for basements.

Use an air purifier

Air purifiers are devices that help to keep the air in an indoor environment clean. They not only remove pollutants that give rise to stale air smell, but can also remove the smell efficiently.

Air purifiers get rid of mold spores that can be suspended in the basement air, thereby reducing the chances of mold to spread to other parts of the house.

HEPA filters with an activated carbon filter as well as a germicidal UV light chamber are the best option for getting rid of the stale air smell in a relatively short amount of time.

However, it is important to note that air purifiers should not be used in high humidity conditions, as humid air is heavier than normal air, which causes overworking of the air purifier, thereby decreasing its efficiency.

Another reason for doing so is that the mold spores entrapped within the filters can start proliferating in there itself, which in turn can exacerbate the air quality.

Other FAQs about Air Quality that you may be interested in.

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A basement even if dry can smell musty due to factors such as high humidity levels, presence of leaks and seepage, use of faulty air maintaining appliances, and storage of items containing cellulose.

Under such conditions, the growth of fungal mold can take place, which releases mold spores in the basement air, which not only creates the musty odor, but can also adversely affect the health of the occupants.

Therefore, it is important to first use an air dehumidifier to dry out the basement air, check and fix any leaks and seepage present in or near the basement, using an air purifier to get rid of mold spores as well as odor, and to regularly clean the basement, particularly the items stored in it.


Do air fresheners and essential oils help to get rid of bad smells in the house?

Yes, air fresheners and essential oils can help to get rid of bad smells in the house. However, this is only a temporary solution, since once the effect of these fragrance compounds fades away, the sources of odors are still persistent, thereby causing the bad smells to occur once again.

As a solution, it would be ideal to rather identify the sources of unpleasant odors in your house and take care of them, as this is a viable solution that would last for a longer time.

Are there any alternatives to get rid of the musty smell?

Yes, there are other alternatives that work just as well as the ones mentioned above. You can place bowls of white vinegar, cat litter in open containers, or baking soda throughout your basement in order to absorb the stench. 

You should notice a more pleasant smelling basement in a couple of days. These substances act as absorbents to water vapour and the odors.

However, being slower than the methods mentioned earlier, these end up taking a considerable amount of time, and may not be as efficient as the methods previously explained.

Does DampRid work in a basement?

Yes, DampRid works efficiently in order to get rid of excess moisture from the basement. 

DampRid Hi-Capacity Moisture Absorber Bucket attracts and traps excess moisture, eliminating musty odors from damp areas.

The hi-capacity design features a unique Moisture Lock spill resistor technology with a sealed safety cover for a mess free solution.

It is ideal for larger spaces like basements, garages, where stagnant air and excess moisture is a problem. The 4 lb. Hi-Capacity bucket lasts up to 6 months, depending on temperature and humidity levels.

Why does my basement smell like gas but no leak?

This can happen due to the presence of sulfur in the indoor ambient air. Sulfur, like gas, has a characteristic rotten egg smell. This can emanate from sewage traps present in the basement levels, or from organic discards as well.

However, it is not necessary that it will always be the case. Gas leaks are hard to spot, and even if it isn’t in your house, there might be chances that there is a leak in your neighbouring house.

In such a case, open all doors and windows, and contact a professional who can help better.


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