The Ins and Outs of Mildew Smell

What is Mildew Smell?

The term mildew often refers to an overgrowth of mold. Mold is a common type of fungus. Mold is found everywhere, indoors and out- this is largely due to the fact that mold spores are spread through the air.

Usually mold does not cause any problems, and goes unnoticed. It is only after mold begins to grow quickly and build up on a surface, such as walls, floors, or fabrics, that the musty odor commonly referred to as mildew smell is produced.

So what produces the musty, unpleasant smell? Well, some of the most common types of mold (like black mold) are categorized as microbial volatile organic compounds. In simple terms, this means they emit a gas as they grow.

The smell you notice is simply the gas being released, which is very noticeable in an enclosed space where the gas becomes concentrated.

What Causes Mold Growth

In order to grow and thrive, mold requires three things: moisture, a food source, and time.

  • Moisture can be from any number of sources; a flood, plumbing leak, or simply a high level of humidity is enough.
  • As far as food sources, mold consumes dust, dander, and other microscopic particles for energy. Building materials, including plywood, carpet, and flooring pads, are a great source of nourishment for mold.
  • The other factor that contributes to mold growth is time. Mold can grow to noticeable or troublesome levels in as little as twenty four hours, under the proper conditions. Conversely, it could take several days for mold to become problematic.

Getting Rid of Mildew Smell

mildew smell help In order to banish the musty odor, the underlying problem of mold must be corrected. Getting rid of mold will prove beneficial, as numerous ill effects to the health of people and pets could occur if the problem is not addressed.

Find the Source

This may require some investigation, and some special equipment, but will be well worth it.

  • Begin with a visual assessment, looking around for visible proof of mold infestation. Generally visible mold can be found in the areas where the musty smell is obvious.
  • Sampling may be conducted, but this is only recommended if ill health effects have begun in occupants of the space. (Remember, mold is spread by spores traveling on air current, so sampling could make a not so serious mold infestation worse. Then, getting rid of mildew smell will take a backseat to the larger problem.)

Types of Sampling:

  • Air: special equipment monitors level of mold spores present in the air
  • Surface: Dust samples are used to detect mold spores
  • Bulk: materials are removed from the space for offsite testing
  • For mildew smell in car, the most common culprit is liquid spilled on upholstery, or high humidity.

Attack the Problem

The method of removal of mold, and the accompanying mildew smell, depends greatly on the item or space being treated.


Take the item outside and brush off visible spores. If it is washable, wash in detergent, and if a seconde was is needed, you can add salt, lemon juice, or bleach to the water. Dry the item in the sun. Read about other tips on removing mildew smell from clothes.

If the item is not washable, have it dry cleaned.


Wipe with a 50/50 mixture of water and rubbing alcohol, and dry near a fan. (Fungicide soap works on more stubborn cases.) This can also work in cars with leather upholstery.

Upholstered furniture/ mattresses/ rugs and carpets:

  • Take it outside to remove loose mold, then vacuum up the excess. (Empty the vacuum outdoors afterwards!)
  • Get the item as dry as possible.
  • Use a damp sponge and soap/shampoo to get persistent spots. Use as little water as possible.
  • If necessary, use a fungicide.


  • Heat and air circulation are the best ways to get rid of mold in wood.
  • Clean the wood (disinfectants work well), rinse, and allow to dry complete.
  • Mold growth under paint or varnish requires that said paint or varnish must be removed.
  • Badly infested wood may need to be replaced.

Mildew Smell in Car (with Fabric Upholstery)

  • The best way to get the smell out of a car is to ventilate it.
  • Dry non-removable surfaces as thoroughly as you can.
  • Remove wet or damp floor mats and lay in the sun to dry, and leave the windows down.
  • Apply a layer of baking soda to the car’s interior, and vacuum it out the next day.
  • Use an odor absorbing product made for vehicles to get any remaining scent out.
  • Use a cotton swab dipped in cleaner or disinfectant to clean the air vents.
  • If the smell remains, you may need a professional cleaning.

Keep Mold/Mildew from Returning

A little vigilance and attention will go a long way in keeping the mold and mildew from coming back after it’s been eliminated.

  • Cleanliness: Keep the areas where mildew can thrive as clean as possible.
  • Eliminate dampness/humidity wherever possible( using heat, ventilation, moisture absorbing agents).
  • Avoid using lumber that is new or unseasoned.
  • Treat leather with preventative sprays made for this purpose.
  • Use enamel paint on indoor wood surfaces- it is less hospitable to mold/mildew.