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Musty Smells

A musty smell in your property that is concentrated in your basement is a serious problem. It’s a sign of dampness and water damage you should not ignore.

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While your basement may not be the most delightful part of your home, it should not be dank, damp, or filled with bad smells. If your basement has a noticeable and unpleasant smell of any kind, it is very likely that there is damage at the root of it. If you deal with this underlying cause, you will be able to rid your home of that smell once and for all.  

A musty smell in your basement, therefore, is a very general problem sign that something, somewhere, has gone wrong. By investigating your basement and considering the other problem signs that may be present, you can narrow down the possible underlying causes significantly before you call in a local expert to assess and rectify the situation in your home. For homeowners in Cincinnati and Columbus, Ohio, Ohio Basement Authority should be high on the list of professionals to call.  

What are Musty Basement Smells a Sign Of?  

Musty basement smells can be a problem sign for many different issues. In fact, it’s most often a sign of a combination of many different issues that are occurring simultaneously. Each of these issues are likely to contribute to bad smells in your basement, but they can also cause secondary and tertiary damage.  

Problems with Dampness  

Dampness and standing water in a basement are some of the most common causes of musty smells. However, the smell of stagnant water alone is not often strong enough to cause serious discomfort to most homeowners. There are countless basements that smell a little damp, after all. The main issue with dampness and humidity is that it causes further damage, and creating the most pungent smells.

The most common internal causes of dampness and humidity are plumbing leaks and failing appliances. A leaky hot water heater, for example, can cause a huge increase in relative humidity in a property.  

Mold and Mildew Formation  

mold in your house

Mold and mildew are often the results of dampness. They are also the most likely cause of a very strong, musty odor in any space. If the smell in your basement is slightly dry, sweet, and powdery in a way that irritates your throat, mold is likely to be the caus. Mold and mildew are most likely to take root in damp, dark spaces at first, so you should check behind your toilet or fridge if you can smell it but not see it.  

However, when they start to spread, mold and mildew can cover any kind of surface. In fact, some mold species even thrive best inside HVAC vents.  


Dampness and water are sure to lead to rot when they encounter textiles, wood, and other organic materials. When this comes together with mold and mildew, the process is incredibly quick and damaging. It is also likely to cause one of the most actively unpleasant and powerful odors. If you have active rot in your basement as well as mold, the smell will spread through your home.  

Pest Infestation  

Pest infestations are notoriously unhygienic, damaging, and smelly. Depending on the creature that is infesting your home, the smell could be fairly mild or incredibly strong. It also depends on the severity of the infestation, of course; one mouse might not make all that much of a smell, but a few nests clumped together might.  

The most unpleasant and pungent of infestations, of course, is a cockroach infestation. Cockroaches are incredibly dirty, spread bacteria everywhere they go, and shed their exoskeletons often. As a result, the smell of their presence and excretions can be incredibly strong. It has a unique and unpleasant oily edge to it.  

Clogged Drains or Sump Pump  

While a fully clogged drain or sump pump could cause full-scale basement flooding, a partial blockage or sediment buildup is far more likely to cause slow draining and a strong odor. This will be especially bad if the material causing the blockage is organic and has started to rot. In this case, thankfully, you should be able to erase most of the smell by flushing the system.  

Damaged Sewage Main  

If the cause of the bad smell in your property is a damaged, blocked, or burst sewage line, you will not be in any doubt about it. The smell of raw sewage is incredibly strong and brutally unpleasant, and it is, of course, the last thing you want in your home. Thankfully, sewage lines do not crack often. In fact, the thing most likely to cause damage to the main sewage pipe is invading tree roots.  

These are some of the only things strong enough to damage the main sewage line. Unfortunately, this means that a compromised sewage pipe is very hard to fix (and the smell will be even harder to get rid of).  

Foundation Problems  

Any foundation problem is likely to let water into a property. This, of course, will lead to dampness and humidity, and inevitably, a slightly musty smell in the affected area. However, if your musty basement smells are being caused by foundation damage, you have far bigger problems to worry about. The most common kinds of foundation damage are settlement and subsidence.  

Foundation settlement is most often caused by dry, receding, or weak soils that shift under a property and cause voids to open. The property’s foundation, struggling under the weight of its load, will crack and sections can sink into these voids. When the soil becomes saturated, water will seep into the property.  

Subsidence, however, is far more likely to be caused by wet, loose, or expansive soil. Subsidence is a process of overall sinking that can cause large cracks to advance throughout a property. These cracks will let water into the home, but that is the least important part of the problem.  

Of course, a bad smell is not enough to tell you just what is going on in your home. As such, it is a good idea to be aware of the many other problem signs that can help you to understand how serious the situation is.  

Other Problem Signs You Should be Aware Of  

Of course, musty basement smells are not the only warning sign that you should be aware of. In fact, this problem sign is so general that it is no more than a prompt to investigate further. If you see any of these further problem signs around your basement or throughout the rest of your home, however, you will be able to gain an idea of what is likely to be the issue.  

flooded basement

Standing Water  

Pools or puddles of water that form without obvious reason in your home are an obvious warning sign you should not ignore. Standing water can signify leaky pipes or appliances, blocked drains, seepage, damaged windows, and several other issues. As such, you should call in a professional to help you understand the underlying causes.  

Spreading Cracks  

Some small hairline cracks are normal in most properties. The process of settling (not to be confused with settlement) can cause small cracks to form, but they should be static, meaning they should not grow. If you see cracks that are wide enough to stick a credit card into or that seem to be actively spreading across a surface, it is important that you contact someone to investigate properly.  

Damaged Drywall  

If you have drywall panels in your home, they will be the first to show signs of damage when humidity and dampness start to creep up. Look for signs like bubbling, peeling, bulging, sagging, and staining. Likewise, touch the drywall to make sure that it is not wet, soft, or springy.  

Bowing Walls  

If you notice your basement walls are starting to lean or bow, you should act very quickly. This is a serious structural issue, on par with foundation damage, and it will only get worse over time. Bowing walls are those that have been affected by extreme lateral force, usually from hydrostatic pressure and the weight of water in the soil. Bowing walls will cause dampness long before they develop a noticeable and defined bulge, so watch for spreading cracks that seem to be dark with moisture.  

Sagging Floors  

Dampness and humidity pose a real risk of wood rot forming in exposed support beams, joists, and floorboards. When this happens, the wood can start to warp and rot, losing its ability to bear the weight it was intended to. Over time, this will lead to sagging floors.  

Floor and Wall Gaps  

When flooring becomes damaged and warped, it will start to pull away from the walls that it is attached to. The more a floor sags, the more pronounced the gaps between the floor and walls will become. This can contribute to things like the stack effect, which sees an increase in airflow through and around your home. If left without support, floors will eventually collapse.  

Each of these signs can be connected with a number of different problems in a home. That’s why it is so important that you hire an experienced professional to assess your home as soon as you see them.  

A basement and foundation specialist will be able to correctly identify all underlying causes in your home, as well as formulate a tailored solution that addresses the particular needs of your home. This will ensure that you only have to deal with this issue once (which is more convenient but will also keep your repair costs low). All you have to do is make sure that you find the right professional for you.  

Musty Smells


If you have noticed a bad smell in your basement that no amount of cleaning seems to fix, please do not despair. While this is a frustrating and often complex issue, the underlying causes can be fairly easy to deal with (when you have the right help) 

Dampness and Humidity  

Dampness and humidity are some of the most damaging issues that any home can face, and they can be caused by a number of issues. Nonetheless, the most common are structural damage and damage to your property’s internal plumbing system. This damage can be caused by shifts in the soil under and around a property, weak joints between pipes, and appliance breakdown (to name a few causes).  

If you have basement windows or crawl space vents that are unsecured, the dampness in your property could be caused by increased airflow. Known as the stack effect, or the chimney effect, this occurs when there are ventilation points at the top and bottom of a property. This not only destabilizes the interior climate of a home but will also increase condensation by bringing in warm or cool air from outside and allowing it to clash with the air conditioned by your HVAC system. Dampness can cause a generally musty smell.  

Pests and Mold 

If the smell in your home is a little more than just musty, it is possible that odor could be the result of mold formation, wood rot, or pest infestation. Each of these issues produces a distinct and unpleasant smell that can be hard to ignore, of course, but there are other side effects that are more pressing. Wood rot, for example, has a very pungent smell and can lead to widespread damage to your flooring and even your walls.  

Pest infestation, too, can cause damage to your home, but is more likely to cause damage to your health and wellbeing. The most common pest infestations are cockroaches, spiders, rodents, and termite, and each has a slightly different smell. Rodent infestation, for example, causes a home to smell like urine, while a cockroach infestation may smell sharp and vinegary.  

There are many things that you can do to mitigate or remove a musty or unpleasant smell in your home, of course, but the methods which are most effective depend on the situation in which you have found yourself.  

Repair All Damage 

The first step in removing any smell from your home is repairing the damage that has allowed moisture, humidity, and pests to enter your home. This means lifting and leveling any sunken concrete slabs, reinforcing bowing walls, repairing damaged pipes, and resealing basement windows or crawl space vents and doors. This will give you a clean slate from which to work.  

By preventing water and moisture from getting into your home and repairing the damage that has been done to your property as a whole, you will cut off the source of the smell. This work is key to ensuring that the results you get from cleaning up the pests, mold, or growths which are causing the smell are permanent. After all, you don’t want the smell to come back!  

Remove Pests and Moisture  

Once the structure of your property has been repaired and the integrity of your plumbing system has been assured, it will be possible to take appropriate measures to remove the mold, fungal growths, or pests which have created the bad smell in your home. Depending on the nature of the problem this can be a fairly lengthy process.  

Pest removal, chemical removal of mold, and dehumidification may all be needed, alongside a deep clean, depending on the nature of the damage in your home. This is why it is important to talk to a professional about the smell of your property and what you can do about it. Experts have all the information and tools they need to return your home to full health.  

Dampness and humidity will not only make your basement unhealthy – they could also impact your property’s climate and even undermine your health and wellbeing. Waterproofing is the only way to guarantee that this issue will not recur.  

The Benefits of Waterproofing 

Waterproofing your properties foundation and basement will have many benefits which you should not ignore. As well as preventing benign water incursion because of seepage, it will prevent the stack effect from impacting your home and its internal climate. There are benefits which go beyond simply preventing water from getting into your home.  

One of the biggest benefits of waterproofing is how it increases energy efficiency. By reducing humidity and adding extra insulation, waterproofing stabilizes the airflow in your home and increases the retention of the heat and cold created by your HVAC system. It also makes the air easier to process. This means lower energy bills in the long term.  

Why You Should Not Go It Alone 

While we understand that DIY can be a tempting prospect, we urge you to contact a professional to discuss the needs of your home and the waterproofing which should be undertaken. Professionals have the skills and experience to deal with any complications which might arise. Secondly, professionals have access to the best tools and products.  

While you might be able to get versions of the right products over the counter in your local hardware store, professional grade items can be harder to come by. This is because they may only be available through professional supply stores or from their manufacturers. As such, DIY jobs can be less effective, less durable, and still cost as much as professional services. This is why it is best to call in an expert when you notice signs of dampness, humidity, and condensation.  

Ohio Basement Authority Can Get to The Root of Musty Basement Smells  

If you have noticed musty smells in and around your basement, dampness is the most likely cause, but there could be many different kinds of damage at the heart of the issue. From foundation damage to internal leaks, many different factors can contribute to dampness in a property. Thankfully, the Ohio Basement Authority team is qualified to deal with them all. No matter what is going on in your home, we can help you make it right.  

As the resident experts in basement waterproofing and foundation repair in Cincinnati and Columbus, Ohio, we have seen it all. No matter what you think might be the cause of your musty-smelling basement, the repair process starts with an assessment. Contact us today to schedule your free inspection and repair quote.  

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Serving Greater Columbus, Cincinnati, Dayton, and Northern Kentucky

Cincinnati Office

1270 Hillsmith Dr.
Cincinnati, OH 45215

Columbus Office

2421 McGaw Rd.
Obetz, OH 43207

Dayton Office

70 Birch Alley, Suite 240
Beavercreek, OH, 45440