How To Make A Basement Smell Better [9 Helpful Methods]

The long and short of it is that basements often smell. You know, the musty, slightly wet kinda moldy smell. Well, if you have a basement odor, take heart. You are not alone, and we have gathered all of the best remedies to basement smell and go over them here.

The best way to make basements smell better are as follows:

  1. Improve Ventilation
  2. Reduce Humidity
  3. Make Any Necessary Repairs
  4. Clean, Clean, Clean
  5. Abate Mold & Mildew
  6. Check Dryer Vent
  7. Pest Control
  8. Waterproof Basement
  9. Install Sump Pump

Keep reading the rest of this post for details on each of the above bullet points. To set the context, we will begin by exploring why basements smell in the first place. To conclude, we answer several questions related to this post's topic.

A basement turned into completely renovated for modern family living, How To Make A Basement Smell Better [9 Helpful Methods]

What causes the basement smell?

Basements smell for a number of reasons. However, the cause of that typical musty basement smell is excess moisture and the mold and mildew the moisture breeds. Basements are generally belowground, so they are surrounded by wet, damp earth. No matter the quality of construction, some moisture will eventually begin to seep in.

This seeping is present in all climates but expect worse basement odor in wet, humid areas. The bad smell of basements is also compounded by the low use of these areas. Often, basements function as storage and extra space. This leads to less frequent cleaning and a higher likelihood for repairs to go unfinished.

How do you deodorize a basement?

Each of the following sub-sections deals with a specific technique for fixing basement odor. However, many basement smell issues will require a combination of the following strategies. Take a look at all of these strategies and pick and choose based on the situation in your specific smelly basement.

1. Improve Ventilation

Ventilation improvement starts off our list because it is easy and cheap. Whether you have a very bad odor issue or a minor one, improvement to airflow will help with the smell. This strategy aims to reduce basement humidity and to bring in fresh non-smelly air.

While not recommended during a rainstorm, simply opening a couple of windows or doors generally improves ventilation. Note, though, that it is important for windows left open to have high-quality screens so bugs and other pests cannot easily enter the basement. Open windows on hot, dry days, or leave a couple of windows open that encourage the flow of air through the entire basement.

Other ventilation improvements include plug-in fans and even installing a whole-house ventilation fan like those in bathrooms. Sometimes, you will also need to service your HVAC system or perhaps just change out a furnace filter.

2. Reduce Humidity

Humidity reduction does include ventilation but goes far beyond a simple improvement in airflow. The reduction of humidity involves the use of specific humidity reduction tools and removing sources of unwanted water.

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Specific humidity tools include the over-the-counter humidity absorber available at most home-improvement stores. These traps suck water out of the air to reduce relative local humidity. Another option is mechanical dehumidifiers. However, no moisture absorber can keep up with a consistent water supply.

For this reason, humidity control also involves removing unneeded sources of moisture. This might involve more in-depth repairs, which we cover below. However, sometimes all it takes is removing a fish tank, quickly cleaning any spills, pest removal, tightening pipe fittings, or hang-drying clothes elsewhere.

3. Make any Necessary Repairs

Sometimes, the source of moisture in your basement is not an easy fix. Water that routinely pools alongside foundations, bad leaks in foundations or plumbing, or seasonal flooding all lead to high basement humidity and that bad smell. 

Male Worker Inspecting Water Valve For Leaks In Basement

Take a thorough look at the source of moisture and take steps to remove that source. For simple issues like plumbing leaks and small water pools, you can often perform the fix yourself. However, more difficult fixes require hiring a contractor. If you have a cracked foundation wall, for instance, it is wise to hire someone with the know-how to perform a fix that will last a long time and look good.

4. Clean, Clean, Clean

In addition to moisture, the smell of a basement comes from a buildup of dirt and grime. Generally, basements exist out of sight and out of mind - so out of the regular cleaning routine. For minor smells, regular cleaning started with a deep clean might lead to significant improvement. Dirt and grime also provide mold and mildew a place to grow.

For persistent odors, you will want to combine cleaning with other items on this list. In fact, if you take the time to remove moisture sources and to improve ventilation, it is wise to also clean. The cleaning will help remove the bacteria and mold that make the smells in the first place. A good deep clean helps prevent the smell from returning as soon as your odor removal work ends.

No matter the strategy you choose for deodorizing your basement. Incorporate regular cleaning into your new plan. Regular cleaning is the cheapest and easiest way to prevent the bad smell from returning.

5. Abate Mold and Mildew

For small mold and mildew stains, regular cleaning should work. However, for really persistent mold and mildew growth, you might need to bring out the big guns. This includes borax, Kilz, carpet replacement, and more.


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Borax is an all-natural mold and mildew fungicide. Following the directions on the container, make a mix of borax and water to clean any moldy areas. This should kill the mold and prevent regrowth. Once the area has fully dried, take the time to clean any stains you would like with a bleach solution.


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For bad areas of mold and mildew on walls and floors, Kilz might be just the ticket. This primer not only will serve to freshen up your basement's look but also kills mold and mildew. For the best results, use a combination of borax and Kilz.

Carpet Replacement

Sometimes, mold and mildew will infest carpet or other soft goods. The only choice in this situation is a replacement. Before you take the time and incur the costs of carpet replacement, be sure that you remove the source of the original water. It is not a good feeling for the new carpet to get damaged just like the old.

If you do decide to replace or add new basement carpet, check out this great article, "Best Carpet Types And Colors For The Basement."

Hire a Professional

Housekeepers Hand With Glove Cleaning Mold From Wall With Sponge And Spray Bottl

For really bad mold and mildew infestations, it is recommended that you hire a professional. First of all, breathing mold and mildew is bad for your health. Secondly, professionals have the experience and know-how to really get rid of all your mold and mildew. It is no easy task removing a bad mold infestation, and if you leave even a few spores behind, the problem can come back with a vengeance.

6. Check Dryer Vent

Sometimes, dryer vents get clogged with lint. This clog means that the moisture your dryer is removing from your clothes cannot properly make it out of the vent opening. Take the time to ensure your dryer duct and vent allow air to escape easily.

Clogged dryer vent outlet

This is an easy fix but an important one. A dryer vent can also provide mice and other rodents a path into your home. If you discover a dryer vent or duct issue, make sure to fix it ASAP. This usually involves replacing dryer ducting with holes and making sure the vent itself is in working order.

7. Pest Control

Pests bring in moisture and bad smells. As such, pest control is critical to basement odor issues. If you see any signs of pests, take all steps necessary to remove them. Your local home improvement store should have a well-stocked section on pest control. The most effective technique is to tailor your pest control to whatever pests you have, so do your research first.

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Sometimes, it is not that simple to get a pest problem under control. In that case, call a pest management professional. These professionals will take steps to control your pests in both the long and the short term.

8. Waterproof Basement

If you are still having problems with moisture entering your basement after trying the above strategies, take steps to fully waterproof your basement. Home improvement professionals will actually seal all of your basement walls and joints to keep all moisture out.

Waterproofing a basement is also a good idea before you convert an older basement into a newer finished basement. It is much easier to make sure water cannot get into an area before you finish the area than after you finish the area.

If refinishing your basement is the final goal in your basement odor project, check out this great article full of basement decor ideas, "30 Awesome Rustic Basement Ideas (Photo List Inspiration)."

9. Install Sump Pump

Sump pumps are in-ground pumps that pump out extra water from a basement. For basements that ever flood, sump pumps are a must. These pumps are relatively complicated and do require significant structural and electrical knowledge to install.

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Will a dehumidifier help with the basement smell?

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As mentioned above, a dehumidifier is one of the easy ways to help with the basement smell. But be careful; all basement smells cannot be fixed with a dehumidified. Usually, fixing the smell in a basement requires combining a dehumidifier, or similar strategy, with many of the recommendations listed above.

What causes a sewage smell in the basement?

A plumbing problem causes a sewage smell in a basement. The plumbing problem can range from a simple dried-out drain to a damaged sewage line. If you cannot fix the sewage smell quickly, hire a plumber because the sewage odor is unpleasant and unhealthy.

Bathroom with two sinks. Look under the sinks with installations - tubes and trap. Lens flare from daylight. Toned image black and white shades

Often, drains and sinks in basements are not used very frequently. Because of this, the smell traps in the drains dry out. This allows the odor to come up from the sewage lines. This fix is easy and simply requires running water through all of the drains. Try this first if you smell sewage in your basement. 

For more persistent problems, you may be dealing with a bad plumbing seal or even damaged piping. Take the time to problem solve your issue, and do not be afraid to call a plumber. It is always worth it to fix a plumbing issue early before the problem can get any worse.

Does DampRid work in basements?

Yes, DampRid does work in basements. Any area that has excess moisture in the air is appropriate for a DampRid product. However, just because the DampRid is working does not mean your basement odor will disappear. As mentioned above, it usually takes several basement odor abatement strategies to have a basement smelling fresh once again.

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In Closing

This post has given nine strategies for fixing basement odor. Each strategy is expanded upon, including when it is appropriate and how effective the strategy is. In addition, the answers to a few related questions are included in this post. Good luck!
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