Mold Vs Mildew: The 7 Key Differences?

It’s common for homeowners to confuse mold vs mildew – check below for mold vs. mildew. Although both of them are fungus, they exhibit certain distinct features which can be used to distinguish them. Mold Vs Mildew

Correct identification allows you to embark on accurate treatment measures. I’ve featured some important features which you can use to differentiate between mold and mildew. 

Although mold and mildew bare numerous similarities, they exhibit notable differences which can be used to distinguish them. Read Also: Best No See Ums Repellent

Mold Vs Mildew: The 7 Key Differences?

1. Appearance

Mold: Molds grow on damp surfaces as colonies of irregularly-shaped patches. They can be seen on walls, floor, wallpapers, carpet, and wood among other surfaces. Depending on the species, the color of mold ranges from black, brown, green, blue, gray, yellow or white.

Mildew: Mildew appears as a powdery (check fungicide killers) and flattened patch usually yellowish, gray or white. With time the color turns to brown and eventually black.

2. Smell – Mold Vs Mildew

Mold: Molds have a musty and tangy smell which can spread to every corner of your home through the spores. The smell comes from mold growth process which releases microbial compounds into the air.

Mildew: Mildew exhibits a foul and pungent odor which lingers around as long as there’s mildew in the house. This smell results from the mildew growth which produces gases and releases them into the surrounding air.

3. Where do They Grow?

Mold: Mold is both an indoor and outdoor fungi. Outside the house mold grows on moist surfaces such as on soil, dust, walls, water pipes and so on. Mold gets indoors through open spaces or by attaching itself to your body, pets or items you bring home.

When mold gets indoors it thrives in moist surfaces such as on condenser ducts, under the sink, upholstery, walls, ceiling, paper, etc. If not treated mold can disfigure surfaces or lead to structural damage.

Mildew: Mildew grows on damps surfaces especially in the kitchen, bathroom, basement and upholstery. Spores from mildew can also attach themselves on plants whether indoors and outdoors.

Plants are susceptible to mildew especially during warm and humid conditions. Mildew spreads rapidly and may eventually take over the plant. If not treated it can damage the plant or kill it completely.

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4. Effects on Human Health

Mold: Inhaling too much mold spores can lead a number of health complications. Depending on the species, you might get respiratory problems, allergic reactions, asthma attacks, migraines, fatigue, and inflammation and so on.

Black molds contain mycotoxins which are associated with long-term health complications.

Mildew: Inhaling mildew spores may result to health complications such as respiratory infections, coughing, headache, etc. However, complications caused by mildew are less serious than those caused by mold.

Mold and Mildew Testing

You cannot see mold or mildew until it reaches a point where it visible to your eyes. In that case you can differentiate between the two types of fungi.

Sometimes, mold and mildew can originate from hidden crevices where it continues to grow and reproduce through spores. That means the surrounding air will be concentrated with spores which cannot be seen with naked eyes.

Once in the air, these spores are known to cause allergic symptoms which can sometimes lead to serious medical conditions. For this reason, households should be regularly tested for these fungi even if there’re no signs of them. 

Early discovery enables you to remove the mold or mildew before it spreads to the rest of the house. Below is a guide for testing mold and mildew.

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Types of Tests for Mold and Mildew

There’re three types of test you can use to check the presence of mold or mild dew in your house. It’s advisable to use the three methods in order to get accurate results. They include:

1. Air Testing

This is one of the surest way of detecting the presence of mold or mildew. In this test air samples are collected and taken to a lab for inspection. Air testing allows you to detect a mold problem before physically locating it.

Analysis of the results can be used to tell the concentration of spores in the air and the threat it poses to your family. Air testing can also be done after cleaning to check whether the mold or mildew spores have been reduced to an acceptable level.

2. Surface Testing

Sometimes mold and mildew can be confused with dirt that accumulates on surfaces. In that case surface testing can be used to differentiate normal dirt from mold growth. In this test, samples of suspected mold are taken using a tape, a swab or any other possible method.

These samples can be analysed using a DIY test kit or taken to a lab. A simple test can be done at home to check whether the suspected substance is dirt or mold.

In this test a small amount of house bleach is dabbed on the suspected mold growth. If there’s any mold growth, the blackened area will lighten up after two or three minutes.

3. Culture Test

The test kits you get online are only meant to detect mold or mildew growth without identifying the species. However, with a culture test it possible to know which species of mold or mildew you’re dealing with.

In a culture test a sample of live mold particles is collected from your home and grown in a lab. The aim is to grown the mold into a large colony to facilitate its identification.

How to Clean Mold and Mildew

1. Mildew

Mildew can effectively be cleaned from surfaces using a scrubbing brush and an appropriate cleaning agent. That’s because, it doesn’t penetrate into surfaces as in the case of mold. However, mold is more difficult to remove because of its tendency to stretch its microscopic filaments into surfaces.

2. Mold

Mold removal ought to be done with care to avoid spreading the spores to other areas in the house. That’s why it’s usually recommended to seek professional help when you have a mold problem.

If you’re dealing with a small mold or mildew problem you can clean it yourself. Before you begin the cleaning process, ensure you wear a protective face mask so that you don’t inhale spores or fungicide fumes.

Also wear gloves to prevent the effects of the fungi and fungicide on your hands. Below is a guide for removing mold from your home.

Locate and Eliminate Possible Causes of Moisture

Moisture creates a favorable environment for mold and mildew to thrive. Thus, eliminating moisture is the foremost intervention for getting rid of these fungi from your home. Check all plumbing systems or connections for any leakages and repair any faults. Your local plumber can help you fix leakages.

Proper ventilation helps reduce moisture content in high humidity areas like laundry rooms, kitchen, bathroom and basement. You can also install dehumidifiers to absorb moisture in the surrounding air.


With leakages repaired and causes of moisture removed, it’s time to dry your rooms of any remaining moisture. While your house may have dehumidifiers and fans, they may take time to eliminate moisture from indoor spaces.

In this case, you can hire commercial equipment to achieve thorough drying in a short time.

Remove Materials Affected by Mold

Mold can penetrate deep into some materials, making it difficult to remove. If such items are left in the house, the hidden mold continues to grow and reproduce. This creates a recurrent mold problem which requires regular treatment.

To avoid a recurrent mold problem, it’s advisable to dispose all materials that have been severely damaged by mold. If possible, seal the items in plastic bags to avoid spreading the spores in unaffected areas.

Quarantine and Clean With a Fungicide 

If the fungi are located in certain rooms, seal all open spaces including doors, window and vents to avoid spreading spores to other rooms. You can use plastic sheets and tapes.

Mold and mildew are fungus which can be effectively removed using the best mold removers –  fungicides or commercial-grade disinfectants.

Fungicides work by killing and inhibiting fungal growth and reproduction of spores. Does salt kill fleas?. You can get fungicides from your local store or online. 

Using a sprayer treat all the affected areas with the fungicide. Scrub the surfaces with a stiff brush to remove embedded mold or mildew.


Usually, removing fungi from surfaces, can result to damages such as peeled off paint or vanish. Such surfaces will need repainting to restore their initial look. In addition, this prevents moisture absorption thus preventing mold or mildew growth. 


Mold and mildew affects both structures and people’s health. They produce spores which spread rapidly through the air. If left untreated, these fungi eventually get to any corner of the house where there’s moisture and warmth.

A minor mold or mildew growth can effectively be removed using readily available fungicides or disinfectants. However, a full-blown mold or mildew problem might require an expert to help in removal. 


  1. Mold and Mildew | Environmental Health Sciences Center 
  2. A Brief Guide to Mold, Moisture and Your Home | Mold | US EPA 
  3. Mold Basics – Virginia Tech

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