Can Mold Grow Under Carpet?

Mold is not only unflattering to the eyes but it becomes a health risk once the infestation progresses. That's why we understand how big of a deal it is for you to suspect mold growing under your carpet. Don't worry! We have researched everything you need to know about carpet mold.

Mold can grow under the carpet with enough moisture, organic material, and warmth. It only takes 24 hours for mold spores to start growing in an ideal environment. This means that carpeted areas that experience leaks and flooding often are more prone to mold growth.

Mold can be prevented but once it starts growing, would you still have a way to reverse everything? Are there ways to avoid mold under the carpet? That is what this article is all about. Keep reading to find out more about the topic.

Pulled back carpet and padding in room of a house, Can Mold Grow Under Carpet?

How Does Mold Grow?

Before going any further, you first have to understand how mold grows. By that, it will be easier to figure out how to get rid of them and prevent a recurrence. 

4 Stages Of Mold Growth

The life cycle of mold consists of four phases:

  • sporulation
  • germination
  • hyphal growth
  • reproduction

In simple terms, spores are formed during the sporulation process. Then, carriers disperse these inactive spores everywhere. They just sit there and wait for moisture and an ideal temperature to activate them. This waiting time is the germination phase.

The third phase, hyphal growth, begins once the spores become active. From there, they will begin to reproduce, which is known as the last phase of the mold growth cycle.

How Do Molds Enter Your Home?

Mold spores are very tiny particles (between 1 and 100 microns) that are invisible to the naked eye. They stick to plants, shoes, clothes, and other objects. It is obvious how these spores could easily find their way inside your home.

Mold begins to enter your home while they are still in the form of spores. These spores attach to your shoes, clothes, and pets. Unknowingly, you disperse these spores once you enter and move around your home.

Carpets come in direct contact with your shoes and your pets. Therefore, they are one of the first things that get contaminated. 

Open windows and doorways are also another way these mold spores get into the indoor environment. The wind carries them and disperses them everywhere in your house.

Mold spores can also enter through vents and HVAC systems.

How Does Mold Develop Under Carpet?

Black spot of mould on the back of carpet

A lot of things that we have at home support mold growth. Upholstery, paper products, wood, wallpaper, drywall, and even dust can be ideal living environments for mold. Unfortunately, the carpet is no different.

Mold spores quickly develop once the carpet absorbs the right amount of moisture. If not from spills and leaks, flooding is one of its main sources. If you could dry your carpet and your floor thoroughly, then mold is unlikely to thrive. 

On the other side, given that the carpet already contains moisture, it only waits for the right level of humidity and temperature to activate mold growth.

According to the US Environmental Protection Agency, indoor relative humidity should not be more than 60%. The most ideal levels range from 30% to 50%. On the other hand, the most ideal temperature for mold growth range between 72 and 95 degrees Fahrenheit (22 and 35 degrees Celsius)

Can Mold Cause Health Problems?

Mold stains are probably just secondary. Health concerns are the main disadvantage of having a mold infestation at home. While not everyone reacts to mold, some people fall ill after exposure. Children as well as people with allergies, respiratory problems, and asthma are more sensitive to mold. 

Here are some health problems associated with mold:


Mold triggers allergic reactions. Those who are naturally allergic will experience more severe symptoms. Some people will start to develop signs with prolonged mold exposure. It can also cause ABPA or allergic bronchopulmonary aspergillosis. 

Some symptoms of mold allergies include sneezing, dry, watery eyes, scaly skin, dry eyes, cough, and runny or stuffy nose.


People with asthma may experience more frequent and more severe episodes from exposure to mold. Also, babies who live in environments with a severe mold infestation are at risk of developing asthma 3x more than infants living in a mold-free environment.

Immune System

Mold releases mycotoxins that when inhaled, can cause problems with the immune system. A lower immunity can trigger other health problems such as depression, anxiety, and memory loss.

How To Detect Mold Under Carpet

Roll back wet carpet

Over 1000 types of mold species are found in homes, according to the National Center for Healthy Housing. But it should not be difficult to tell if you have mold under your carpet. 

Here's how to check your carpet for mold:

Perform A Physical Examination

Mold comes in different colors. It may be black, green, yellow, brown, orange, or even white. Some mold species look like tiny spots of fur, while others look like fuzzy fibers. Some also look like cotton balls.

Check both sides of your carpet for any visible signs of mold using the description above as your guide. Check also the floor where the carpet sits. Mold is more likely to start growing underneath.

For more information, here is an article on how to remove carpet padding from concrete. 

Watch Out For A Musty Odor

Severe infestation may cause a musty odor. Mold produces gasses called microbial volatile organic compounds. The cycle of mold growth causes chemical reactions that result in the emission of this type of gas.

Use A Mold Testing Kit

Mold may be difficult to detect during the early stages of infestation. You can use a mold testing kit to get a quick answer. Mold test kits are available from different brands online.

View this ImmunoLytic Mold test kit on Amazon.

Removing Mold On And Under Carpet

You have to act fast once you confirm mold is present under your carpet. Doing so will stop the spreading and also discourage further dispersal of spores around your home. Here are methods to remove mold from your carpet.

Use Baking Soda And Vinegar

Baking soda lemon vinegar

Sprinkle a generous amount of baking soda on the stained area of the carpet and the floor underneath. Let it sit overnight. Then, add vinegar and scrub the carpet and the floor using a brush. Rinse thoroughly and allow the carpet to dry completely.

Read this article to learn how long it takes a carpet to dry after using a cleaner: How Long Does Carpet Take To Dry After Using A Cleaner?

Clean With Dishwashing Liquid

Removing stain

You may also use dishwashing liquid and a brush to clean the front and back sides of the carpet. After scrubbing, rinse the carpet thoroughly with water. Do not forget to clean the floor as well.

Spray Grapefruit Seed Oil Or Tea Tree Oil

Choose between tea tree oil and grapefruit seed oil. In a spray bottle, mix a cup of hot water and your preferred natural oil. Spray the solution on your carpet and let it sit for at least 10 minutes. Scrub to remove mold stains and rinse and dry completely.

Use Steam Cleaner

Steam cleaning is another way to get rid of molds. Brushing with steam will not only help loosen up mold stains fast but also help kill the molds and mold spores.

Tips to Prevent Mold From Growing Under Carpet

Prevention is always better than cure. You can do the following to keep mold from growing or recurring under your carpet: 

  1. Always keep the carpet clean and dry.
  2. Keep the humidity levels between 30% and 50%.
  3. Make sure air properly circulates around your home.
  4. Repair all sources of leaks near your carpet.
  5. Dry out a wet carpet as quickly as possible or replace it with a new one.

How Long Does It Take For Mold To Grow In Wet Carpet?

A view of water leaking on the stairs of a home

With the presence of moisture and the right level of humidity, mold species can grow within 24 to 48 hours. They start to become visible in the third week. By this time, they are already reproducing and spreading spores.

What Does Mold Under Carpet Look Like?

What mold looks like depends on the type present in the area. It comes in different colors and may appear anywhere from black furry spots to green fuzzy fibers. Cladosporium is the most common type of mold found on carpets.

Will Mold Come Back After Cleaning?

Steam carpet cleaning with steam and wand

Mold may or may not come back after cleaning. But it needs four things to grow:

  • Mold spores
  • Organic food
  • Moisture
  • Appropriate temperature

Therefore, mold will come back when all of the above are present.

Final Thoughts

Mold can grow under the carpet, but it doesn't just stop there. Thankfully, we already have discussed why it happens in the first place, how you can get rid of it and how you can avoid mold under the carpet from happening again in the future. 

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