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Signs that You Have Mold Under Your Hardwood Floors

Signs that You Have Mold Under Your Hardwood Floors

Mold under hardwood floors is a major problem for many homeowners. It’s especially troublesome in areas with high humidity, such as the kitchen, bathroom, and basement.

However, mold under your hardwood floors doesn’t mean that you should replace your flooring. Instead, when you notice mold growing under your flooring, you must address the root problem and kill the mold. 

Here are some common signs of mold under hardwood floors and how to deal with the situation:

Brown Patches on the Floorboards

You might mistake small brown patches on your hardwood floors as dirt or dust. However, the patches might be due to mold growth. 

While the brown patches are not always visible to the naked eye, mold can grow on any surface that’s porous and damp enough for it to take hold.

You can check for these patches by looking at areas where your walls meet the floor or around skirting boards and architraves. 

A Musty Odor

Mold often occurs in places that are exposed to water. If you notice a moldy smell in your home, it might be that the moisture from leaks is causing an early form of mold. 

Mold produces gas over time; therefore, as the mold grows, so will the odor. 

Stains, Discoloration and Warping Boards

When your basement or crawl space floods, it might leave behind water that seeps into the cracks in your hardwood floors. 

A small amount of accumulated water can cause serious problems. Therefore, checking your surfaces and pipes where water leaks occur is best to avoid further complications with your hardwood floors. 

Fungal Growths on the Wood or Subflooring

If your hardwood floors start looking a little fuzzy, some fungal growth might be ongoing. 

Spongy Flooring

You are most likely dealing with mold if you walk across your hardwood floor and notice that it feels spongy or squishy beneath your feet. 

Suppose you encounter the above signs of mold in your home. In that case, it’s best to carefully examine the areas prone to moisture, such as under the carpets, below the sink, basement, kitchen cabinets, and around appliances that utilize water. 

Once you identify the mold problem, fix it as soon as possible because mold can damage your hardwood floors and your family’s health. 

How to Remove Mold under Hardwood Floors

Do not hesitate to take immediate action when you find mold in your home. First, consider what causes mold on your hardwood floor and how to deal with the issue. For example, if there’s a leakage in your house, ensure that you fix it before you proceed with mold removal.

If you can’t remove the mold completely, consult a wood flooring expert for further guidance. 

Before you start the mold removal process, it would be best to carry uncontaminated items to a mold-free area. For example, seal and take the furniture outside immediately, throw away easily replaceable items if they’re full of mold, place all washable carpets and furniture in the sun and place them after the house is complete.

Next, open doors and windows to allow air circulation in the room. After this, you’ll pry away the baseboard wall trim in the infected area and pull up any transitional floor trim. 

You can remove the whole floor flooring; however, if you think that the mold has only affected a small floor area, you can only patch that area. Remove only the trim needed to access the floor area infected by mold and two feet extra. Once you do this, you can observe to remove mold properly. 

Observe your hardwood flooring; if you need to treat it, pile it from one side and first focus on treating the subfloor. You should start from the corner of the room and pry up hardwood boards. 

You can kill mold under your hardwood floors using these methods:

Use Bleach to Kill Mold

You can use bleach to kill mold, as detailed below:

What You Need:

  • Bleach
  • Water
  • Bucket
  • Spray bottle
  • Paper towels
  • Face dust mask
  • Protective hand gloves


  • Wear a face mask and put on hand gloves.
  • Make a bleach solution in the bucket by mixing water and bleach at a ratio of 8:1. 
  • Mix the solution properly and put it in a spray bottle.
  • Spray the bleach solution in the moldy area and let it sit for several minutes. 
  • Use a paper towel to wipe up the bleach solution.
  • The bleach solution should kill any live mold before it spreads.

Use Vinegar to Kill Mold

The vinegar solution is perfect for removing mold under your hardwood floor. Here’s how to do it:

What You Need:

  • Distilled white vinegar
  • Water
  • Bucket
  • Face dust mask
  • Protective hand gloves
  • Paper towels
  • Spray bottle
  • Broom


  • Wear a face mask and put on your hand gloves.
  • Open the windows to keep airflow inside the room.
  • Mix a cup of vinegar with a gallon of water in a large bucket. 
  • Pour the solution into a spray bottle, treat mold-affected areas, or apply it directly from the bucket if you have large areas to address. 
  • Mop the liquid over the subfloor and wait 10 to 15 minutes to give the solution some time to soak the mold so that it doesn’t release spores.
  • Scrub the area with a broom or brush, apply a new solution again, and wait for another ten minutes. 
  • Wipe the space clean with warm water and let the area dry.
  • If the mold persists, repeat the entire method until you remove the entire mold. 

Use Mold Remover

You can use mold remover to ensure that you remove the entire mold under your hardwood floors. Many kinds of mold removers in the market can get the job done quickly. You can choose one that suits your needs. 

Hire a Professional

Once you’ve identified that you have mold under your hardwood floors, you can seek professional help to help you fix the issue.

You might not know the extent of the mold issue, and it might be a cumbersome job that requires special equipment; therefore, it might be advisable to hire an expert to do the job. 

How to Prevent Mold on Hardwood Floors

Mold can be a serious issue for your health and your home’s integrity. However, you can prevent this issue by doing the following:

  • Maintain a humidity level of 40% or less by using dehumidifiers and air conditioning.
  • Ensure that you use vacuums that are made specifically for hardwood floors.
  • Keep your home well-ventilated.
  • Do not let spills sit on the floor for too long; clean them immediately.
  • Use a squeegee to remove any excess moisture from your floors.
  • Air your hardwood regularly to help avoid mold growth.
  • Apply lemon or cedar essential oils to hardwood floors to protect against molds and bacteria.

Several reasons, such as not cleaning your floors thoroughly enough or humidity in your home, can make your hardwood floors moldy. 

However, if you want to keep your home mold-free and save time and money, you should avoid having too much moisture on your floors by implementing the tips above.