Flooring, Cleaning

Can Mold Grow Under Vinyl Plank Flooring? 8 Mold Cleaning Tips

The word mold is one of the scariest words in a homeowner’s or a landlord’s dictionary. If there is mold in your house, you will have to spend a lot of money to get rid of it.

Mold is a costly and health concern for homeowners. Even waterproof vinyl plank flooring can be vulnerable. Moisture seeping through cracks near water sources can foster mold growth. Look for musty smells and visible signs, or use testing kits. Regular inspections and moisture barriers can prevent mold under vinyl flooring.

We can’t wish it away, but we can’t fix it with a band-aid. It causes health problems like respiratory issues and allergies. Not to mention, the smell is awful!

Can Mold Grow Under Vinyl Plank Flooring? 8 Mold Cleaning Tips

Can Mold Grow Under Vinyl Plank Flooring?

So the question we will be going over today is, can mold grow under luxury vinyl plank flooring

Vinyl plank flooring is waterproof, but liquids can’t seep through cracks or edges, trapping mold. When mold forms, it is due to being around the tub or toilet, which is the best mold environment.

While it is possible, we can still prevent mold from growing under our vinyl planks. How can we stop and fix this problem? Is it harmful when mold grows under luxury vinyl floors? Continue to learn all there is to know on this subject.

How to Tell if Mold is Under Your Floor

If you suspect mold growing under the floors, the best thing to do is check it out in these few simple yet effective ways. Remember that mold may not always be visible like we wish, but there are many ways you can tell if mildew is under your floors.

The primary method is to be vigilant about where excess moisture will be the most, especially in a more moist environment, such as laundry rooms, kitchen, or bathroom areas. Water damage can certainly cause the growth of mold and cause serious problems. Early detection is key to removing mold before it becomes a problem.

Key Things to Look For

  • Watch out for a musty smell: The first step is to see if there is mold by your sense of smell. It will be very unpleasant and most likely resembles something similar to wet socks, a meaty scent, rotten wood, or anything that seems to be earthy-like. It may not be intense at times, but it should be noticeable enough to tell. One way to do this is by going by damp areas such as sinks or toilets, kneeling, and giving a quick sniff. 
  • Keep an eye out for visible signs: Usually, this contains a dark spot in one specific area, stains on the grout of vinyl or tile floors, velvet textures for wood textured surfaces, or distinctive coloring texture (dark green, black, or brown, and sometimes yellow or orange.)
  • Test the affected area with bleach: A relatively quick way to test for mold is by swabbing the area with bleach and dabbing it on the wall (use 1 part bleach, 16 parts water.) If the spot lightens within a minute or two and keeps coming back after cleaning, it is safe to say this is mold. If the area does not move, it is more than likely dirt.
  • Alternatively, use a mold testing kit to detect a mold presence and type of mold within your home.
  • Watch out for any symptoms in your own body: Meaning that you may feel as if you have a sickness that won’t go away, your allergies are always acting out, any asthma you may have is getting worse, and there is no explanation, your body is itchy, or you may be constantly tired. If you experience these symptoms, you may have a mold infestation and a serious health hazard.
  • Check for any leaks in plumbing: Lastly, there may be a plumbing issue that you may not know. Watch the water bill to see if it mysteriously goes up, and check every pipeline that might leak somewhere, as this source may be feeding the mold and moisture under vinyl flooring.

How to Prevent Mold

To prevent black mold from growing beneath flooring, it is important to inspect floors regularly with a mold inspection specialist who can identify potential areas of concern.

Pay close attention to the types of mold commonly growing around water problems since some mold, like Aspergillus Penicillium, maybe more dangerous if left untreated.

In addition, make sure your concrete subfloor is protected with an appropriate sealant or epoxy coating, and keep the wood subfloor or concrete subfloor dry by promptly addressing any general plumbing or water issues in the surrounding area.

Properly sealing such areas, including the wear layer of natural stone, and applying a protective finish will help you maintain an effective barrier between your floor and any moisture problems that could lead to mold growth.

Consider a Moisture Barrier

One of the main ways to prevent your vinyl plank flooring from growing mold is by considering a moisture barrier. Moisture barriers help reduce moisture and soundproof noisy luxury vinyl flooring.

Many contractors will tell you that vinyl flooring doesn’t need a moisture barrier. They claim it’s an extra step that isn’t needed. It is a common misconception that vinyl flooring doesn’t need a moisture barrier when installed over a concrete slab or wood subfloor.

A moisture barrier underlayment prevents moisture from the ground under the slab or inside a crawl space from collecting underneath your laminate flooring and causing mold to grow. I have seen it firsthand when vinyl flooring had moisture underneath it and had to be removed.

This is especially true for concrete floors inside basements. If the contractor has not conducted a moisture, calcium chloride, or RH test on your concrete, it is crucial to install a moisture barrier.

You can quickly get these at a fairly reasonable price, and some of the underlayment companies have warranties provided, so it would be more worthwhile investing in them to ensure better safety over your natural wood-looking floors.

Can mold grow under a moisture barrier? A moisture barrier will certainly help prevent mold from growing under your flooring. It is still possible for mold to grow even with a moisture barrier if it is not sealed properly.

When you install the floor, seal everything to keep out moisture. Vinyl plank options should look like realistic wood and water resistant. This helps them last longer and prevents water damage.

Benefits of a Moisture Barrier

  • Prevent mold and odor: We recommend an underlay because it prevents mold and odor. As mentioned previously, moisture levels can cause a lot of damage to your home and yourself, such as mold growth and respiratory problems. A vapor barrier can also better eliminate the smell in your home. 
  • Protects pipes: When moisture gets in contact with the lines stored in your crawlspace, it can damage the pipes, causing them to break or burst. As learned, mold can form because of this. Having a moisture barrier, for this reason, is explicitly keeping those pipes dry, which increases their lifespan and saves you money in the long run.
  • Pest control: If the floors are not sealed, it may cause unwanted rodents to enter your home, which in return, can be severe issues, such as chewing through the wires or causing health problems. Installing an underlayment closes off any crawl spaces, better eliminating this issue. 
  • Provides better temperature control: Any moisture that gets into your home’s passageway can significantly affect the temperature by absorbing the warmth and keeping it from leaving, which breaks down the HVAC system faster. An underlayment can help control this problem.
  • Conserves energy: Who doesn’t want a more affordable electric bill? Moisture can affect the temperature within your home, causing the HVAC to work harder than it should. Since moisture barriers act as a sealant, they will save you money in the long run.

Is Mold Under Vinyl Flooring Dangerous?

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As discussed above yes, mold growth can happen under vinyl flooring, and it can be hazardous in your home because it causes health issues, which is why it is crucial to get rid of it. A simple misunderstanding is that mold causes lung cancer, but research shows this is not the case unless someone is near a fungus called Aspergillus.

This rare fungal infection can lead to liver cancer. However, mold can cause lung scarring, called pulmonary fibrosis, or PF for short. Mold may also trigger asthma attacks and create your sinuses to swell up and not settle down (also known as chronic sinusitis). If you have a weak immune system or long-term lung issues, then it can lead to worse sicknesses, such as:

  • Pneumonia: inflames the air sacs by being filled with fluid or pus.
  • Pneumonitis: Your immune system attacks the lung cells, causing swelling.
  • Aspergillosis: An infection causing breathing problems and chest pain.

How to Clean Mold Under Vinyl Flooring

Mold can grow under vinyl flooring when moisture is present. Sometimes, mold growing under the laminate vinyl floor may be out of your control. Checking product details, understanding the floor’s life expectancy, and ensuring scratch resistance can help prevent potential issues related to mold growth.

However, follow these steps to clean and prevent mold under your vinyl floors. Remember, with removal, you may have to remove much of the vinyl flooring to remove moisture to ensure it does not come back. Make sure you have the proper equipment to get rid of it completely.


  • Gloves
  • Goggles
  • Respirator
  • Protective clothing and shoes (make sure it is long to not get on your skin)
  • An extra pair of clothes and shoes (for when you are done)
  • Plastic sheets
  • Large garbage bags
  • Disposable rags
  • Tape or nails and hammer
  • Box fan
  • Dehumidifier
  • Two large buckets
  • Spray bottle
  • Borax
  • Scrub brush or broom
  • Heat gun (optional)
  • Pry bar (optional)
  • Chemical stripper (optional)
  • Floor scraper (optional)

1. Remove All Furnishing

First, it is vital to place clean shoes in the room’s front door to ensure you are not tracking black mold in the rest of your home, and then remove all unaffected furniture from the room. If small objects are affected, place them into garbage bags, seal them, and immediately remove them.

You can throw away things that are easy to replace, but for clothes, carpets, and personal items, put them in the sun and take care of them later. This approach is essential when dealing with waterproof flooring options like ceramic tile or flexible vinyl, ensuring their longevity and usability even after exposure to water damage.

2. Seal the Room From the House

Closing the room is where a plastic sheet comes in handy. Hang them from the doors, secure them with nails or duct tape, and then open a window to allow air to circulate through the area.

Place a fan in the window facing outward or put it on the floor facing towards the window. Ensure the fan does not blow directly into the moldy areas; otherwise, more spores will be released. 

Use a commercial dehumidifier to help speed the process and remove moisture quickly.

3. Removing the Baseboards

Remove all baseboards where you know it is contaminated. If you are sure the black mold is in one small area, you can pry those specific flooring sections plus an extra 1-2 feet more to thoroughly clean mold areas. If you see additional mold, be prepared to remove more planks or the entire floor in that area. 

4. Gently Remove the Vinyl Flooring

Remove the flooring, starting with the edge of the room as gently as possible. Cut long slits under the vinyl flooring by sliding a scraper underneath and pulling them up as you scrape.

If the planks are glued down, removing them will require extra effort. Without any hassle, floating or lock-in-place systems can be used instead. For those that don’t want to move, use a heat gun or chemical stripper to pull them up easily and quickly!

If the vinyl planks are in good condition, you may clean and reuse them, so make sure to pile them to one side until the subfloor is mold-free.

5. Mix Borax Solution

With 1 gallon of water, mix 1 cup of borax in a large bucket, fill the spray bottle with the solution, and treat small affected areas. 

If it would be easier not to use a spray bottle, you can work directly out of the bucket using a brush or broom, like paint.

Then, swab the mixture across the floor, waiting 10 to 15 minutes to let the water saturate the black mold and weigh it down to keep the spores from going anywhere. Adding diluted white vinegar can also help with the smell of mold.

After this:

  • Scrub with a brush or broom before reapplying more of the blend.
  • Wait another 10 minutes.
  • Wash the last time.

Doing this several times means the black mold has been ultimately killed off, and you’re on the way to a mold-free home. This process applies to various forms of luxury vinyl, including plank vinyl floor and specific features like vinyl stairnose, ensuring a thorough cleanup in every waterproof option available.

6. Vacuuming the Subfloor

If possible, vacuum the subfloor with a HEPA vacuum to remove the bulk of dead mold. 

On the other hand, another effective way to remove mold is to make another borax solution and rinse it over the floors multiple times using a rag thrown away later. Ensure not to soak the area, which may further create fungus on the subfloor. 

7. Spraying the Subfloor

Clean the subflooring with a light layer of borax water, killing mold from occurring again. Then, make sure it is shriveled before moving to the next step. Turn up the heat and put a dehumidifier in the room for faster service. Wait at least 48 hours to see if the subfloor is withered.

8. Replace the Vinyl Plank Floor

Replacing the vinyl flooring is necessary, as you should not reuse moldy planks. Most warranties cover it, so reapply the clean or new trim before purchasing new floors. 

Lastly, remember to get the moldy items left outside to sun dry and treat them with the borax solution before bringing them inside. This applies to a range of colors in your belongings, be it natural wood furniture or vinyl multi-transition pieces, ensuring all items are thoroughly cleaned and mold-free before use.

Can Mold Grow Under Vinyl Plank Flooring FAQs

How do I know if I have mold under my vinyl flooring?

It’s hard to find mold under vinyl flooring but watch for bad smells, stains, warping, or allergies. If you have a history of water damage, worry. Use a moisture meter or hire a professional for confirmation. Act; mold harms your home and health. Remove it and fix the moisture source immediately.

Can mold grow on vinyl plank flooring?

Mold doesn’t grow on vinyl plank because it’s resistant. But, it does thrive on organic materials like dirt and debris that collect on or under the flooring. The main culprit is moisture, often due to poor installation methods, damage, or humidity. Some classic vinyl plank has organic backing, becoming a mold breeding ground if wet.

Can moisture get under vinyl plank flooring?

Water can get under vinyl plank flooring if it’s not installed or if the subfloor is wet. If there are spills or high humidity, moisture can seep in. A damaged moisture barrier or excessive water used for cleaning can also cause seepage.

What does mold under floorboards look like?

Mold under floorboards can vary in color (black, green, white, etc.) and texture (fuzzy, slimy, powdery). It often forms patches, causing floor damage, warping, or discoloration. Musty odors and allergic reactions can also indicate mold. Check for dampness or condensation.

Final Thought

We’ve answered how mold can grow under quality luxury vinyl plank flooring. Although mold can grow under vinyl plank flooring, it is crucial to detect the issue by looking in humid areas and noticing any change in your health, water bill, or coloring in any corners or crevices.

Seeing it early on can help you create a simple solution before the mold affects the entire house, leading to an even larger issue than it should be. A secure installation of luxury vinyl tile, chosen from a wide variety, can prevent such problems from escalating. 


Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.