how to remove musty smell from basement after flooding

This article discusses the various methods one can use in order to get rid of the musty smell from their basement after there has been water damage, especially from floods. 

What causes the musty smell?

Musty smell refers to the characteristic indoor air which is not fresh, due to which the air has an odor, and feels stuffy. This can happen due to the buildup of certain chemicals as well as humidity in the indoor environment.

Factors that favour formation of musty air?

There are a few chemical species as well as biological components that are responsible for making the air smell musty after a flood. These include:

  • Water vapour
  • Mold and mildews
  • Low sunlight
  • Poor ventilation system

Let us discuss these in more detail

Water vapour

After a flood, the air in the room feels very heavy to inhale. This is primarily due to the presence of water in the vapour form. In higher humidity levels, the air becomes heavier than normal, due to the presence of excess water vapour.

Furthermore, water vapour also promotes the growth of microorganisms such as bacteria, mold, and mildew. These microorganisms further contribute to the odour, thereby making the air musty. 

Mold and mildew

Mold and mildew are fungal species that grow favourably under conditions such as presence of organic material, high humidity, low sunlight, and low temperatures.

These conditions are found in certain areas of the basement, such as corners, carpets, drywall, old clothes, books and newspapers, furniture, and so on.

The spores generated from mold and mildew, alongwith their odor, make the air feel stuffy and produce a stale or musty odor. 

In some cases, these spores can also cause serious health issues, especially in people suffering from a comorbidity, or ailing from respiratory illnesses such as covid.

Poor sunlight

Sunlight is an essential component in order to keep mold and bacteria in check. Adequate sunlight not only keeps the air dry, but also hampers the growth and proliferation of mold and mildew.

However, in a typical basement setting, there are none to poor sources of sunlight, given their position is below ground level. Due to this, damp conditions prevail for a longer amount of time, which in turn allows mold and mildew to proliferate.

Poor ventilation system

Ventilation is an important feature in every house. Apart from the fact that adequate ventilation keeps the air fresh and prevents musty air smell, it also removes the indoor air pollutants by bringing in fresh outdoor air, while carrying the indoor air away.

However, some places lack adequate ventilation, which can happen due to various reasons. In such cases, the indoor air pollution keeps aggregating, and growth of mold and mildew can also take place.

In the case of basements which typically do not have a natural source of ventilation, articles such as clothes, furniture, and walls are more prone to mold and mildew than the other rooms of a  house.

Ways to remove musty smell from basement

As we’ve seen so far, the musty smell is not only repelling in nature, it can also contain substances that can cause serious harm to human health if inhaled.

Therefore, it is important to get rid of the smell as well as the sources from which the musty smell arises from. The following methods can help:

  • Dry out the basement thoroughly.
  • Find spots where mold and mildew is present and eliminate them.
  • Use an air purifier
  • Improve ventilation

Let us discuss these methods in more detail.

Dry out the basement thoroughly

The best way to deal with a wet basement is to turn it into a dry basement. For big articles such as carpets, clothes, and other such stuff, it would be ideal to line dry them, and later wash them using baking soda and normal detergent.

Next, make sure you have thoroughly drained out all the remnant water from the floods. Any presence of water will provide the ambient conditions required for mold to develop.

While you are busy drying out the material present in your basement, it is also vital to dry out the air in your basement. This can be done using an air dehumidifier.

A refrigerant dehumidifier, the most common type of dehumidifier, operates by using a fan to suck warm air currents into its coils. Warm air condenses when it passes through the machine’s chilled coils, leaving condensation inside the dehumidifier.

As the condensation gathers, one droplet of water at a time, it falls into a dehumidifier-connected storage tank. Through the opposite side of the machine, cooler, drier air is sent back into your house.

An air dehumidifier should be able to reduce the humidity in the air to 30 to 50 percent relative humidity. Many dehumidifiers come with a metre that monitors the relative humidity in the area where they’re installed, and you may adjust the humidity to the desired percentage.

However, in certain cases, if the humidity is too high, one should consider using a desiccant air dehumidifier. These devices use chemical reactions in order to dry out the air, and can reduce the humidity to anywhere between one to forty percent.

Eliminate mold and mildew

Based on what we’ve seen so far, as long as dark, humid, and cool temperature conditions prevail, mold and mildew will proliferate to  a point where it becomes a nuisance in other parts of the house as well.

Therefore, it is important to get rid of any existing colonies before they spread to other places, thereby wrecking more havoc.

For smaller spots, one can simply scrub them out using some detergent and water. However, one should not use bleach, as it only affects the surface of mold.

However, for bigger mold colonies, it would be ideal to hire a contractor who is trained in treating mold.

In the case of articles such as clothes, carpets, furnitures, using baking soda along with detergent and water to clean them out, followed by line drying in ample sunlight can help to get rid of mold from them.

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.

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. 

HVAC refers to Heating, Ventilation, and Air Conditioning. They help to regulate the room conditions in a manner that prevents growth of mold.

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.

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

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Due to water damage caused by floods, the basement can develop a musty smell, due to high humidity levels, presence of mold and mildew, poor sunlight, and poor ventilation systems.

In order to get rid of the musty smell, one must dry out the basement thoroughly by using air dehumidifiers, heat, and other methods. Next, wash articles that have mold growth on them, and scrub mold off from surfaces if it is small enough. 

In case of large mold patches, hire a technician who can take care of the problem. Finally, increase the ventilation in order to get rid of the musty smell from the basement and allow fresh air.


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.