Black mold on floors

Black mold on floors and under (sub)flooring can be a frightening thing to find in your home. We have all heard the horror stories on the side effects and how hard it can be to get rid of. If you have found it, chances are you are looking for a fast and effective remedy to have a mold-free home once again.

We can discuss how to do that in a few simple steps!

black mold on floors

Table of contents

Black mold growth

Black mold requires a moist environment to flourish and grows on materials that are high in cellulose. Since this accounts for much home-based material, it can cause it to grow on many surfaces within your house. If you notice black mold on your flooring, you will want to rectify it right away, as it can develop under the surface and spread.

Typically, it is found in basements due to basements being prone to high moisture levels. It can also develop around poorly sealed windows, bathroom areas or in kitchens.

It spreads from spores, which means that if you stir up the area, the spores will travel. This can be incredibly dangerous to inhale to humans. For health and home hazard reasons, it is imperative to efficiently remove from all affected surfaces.

You may notice a growth on wood, hardwood, laminate, vinyl, and concrete surfaces.

Why does black mold grow on floors?

It can be tricky to find, as it can grow on subflooring and joists. This means it can grow under carpets, tiles and other types of flooring which can be difficult to spot. It requires a moist environment to grow and thrive, thus it will be in areas that experience moisture. This can include kitchens and bathrooms.

Since it grows from spores, once inside of your home, these spores gravitate toward these naturally damp areas. After they have established a favorable area to grow, it can then spread. Spores are tiny, airborne reproductive cells that mimic the function of seeds. If they are stirred up, they can travel to other areas.

How to identify black mold under flooring?

There can be key indicators that moldy areas are growing inside of your home. A huge telltale sign is when a room in the home has a musty smell. If you notice this happening in one specific area, this can be a cue to check the room for traces of it.

This is especially true if you notice an area with visible signs of water damage. If there is a scent of mustiness accompanied by water damage, you may need to look deeper than the surface to discover the source.

Recommended read: How to identify black mold

Black mold on floor joists

If you pull up the flooring, the issue presents itself as a greenish-black gelatinous material. When wet, it can appear to be gooey. When it runs out of a water source, it can appear powdery and black.

Joists are just one portion of the floor that can contain black mold. If you gently pry up the flooring and notice black mold on the joists, you will need to remove it right away. Since spreading can be an issue on the joists, assistance from a professional may be beneficial.

Mold on subfloor

The subfloor is the hard material of your floor between the top layer and the floor joists. Usually, your subflooring is made from plywood or oriented strand board. Because wood is a mold-favorite, it can get on the subflooring and floor joists, spreading under the surface.

If you discover there is mold on the subflooring, you will want to remove it carefully. There are a few mixtures that you can spray onto the mold to kill and remove it- such as measured doses of Borax and water.

This can be an issue in both main areas and basements. While you can treat subfloors yourself, you can also look to a remediation specialist for this.

how to remove mold from flooring

How to remove mold from flooring?

Depending on the flooring material, you can use at-home removal remedies to kill and remove it from affected surfaces.

You will want to be very careful, as breathing in spores can be hazardous to your health. Since you will be working with both chemicals and moldy surfaces, it is best to wear gloves, a mask, and safety glasses.

When finished, always be sure to put washables immediately in the washer to not spread any spores that may have gotten on your clothing.

Remove from hardwood floors

Before you begin treating hardwood, you will want to make sure the wood is completely dry. Drying will help you during cleaning and prevent further growth.

If it has penetrated the wood or is deeply engrained in the hardwood, you will want to use a scarping tool or heavy sandpaper to remove it.

If the hardwood hasn’t been penetrated, you can use vinegar and water, soap and water, bleach and water or another household solution to kill it. Hardwood can be affected by heavy chemicals, so do be mindful.

Remove from wood floors

As with hardwood, you may notice warping or staining from the affected areas. It can also seep through the wood, causing it to be deeper than it first seems.

You can then add an 8:1 ratio of diluted bleach and water. Spray on the area and allow it to sit for several minutes. Bleach will prevent further spreading and kill existing mold.

If it seems to have penetrated the wood, you can use a scraping tool or brush to match the depth of growth.

Remove from vinyl flooring

To remove a growth from vinyl flooring, mix 2 tablespoons of bleach into one quart of warm water in a spray bottle. Shake well. Apply it to the moldy surface on the vinyl flooring.

With gloves and mask on, you will want to dip a scrub brush into the solution to scrub away the surface mold on the vinyl area. You can towel dry when finished.

Rinse the floor to see if any residue remains on the vinyl. If not, you may now mop the floor and dry it very well.

Remove from laminate flooring

For laminate floors, it will need to be cared for with minimal chemical use. Chemicals can damage the laminate.

First sweep away any dirt or debris with a broom or vacuum cleaner on the laminate. Mix equal parts of vinegar, rubbing alcohol and water into a bucket.

Spray onto the laminate surface where it is showing. Scrub gently. Rinse and repeat if necessary. When done, be sure to dry the laminate surface completely.

Remove from concrete floors

For concrete floors, commonly in basements or the garage, be sure to start by scrubbing the area with a broom to loosen up the moldy surface. Then, mix water and detergent that does not contain any ammonia ingredients. Pour it onto the floor and work the mix with a broom or scrub brush to ensure it is getting into all the grooves to help removal.

Fill a bucket with clean water. Begin to mop up the area of affected concrete. Once the area dries, you can visibly see how much mold is left on the concrete, if any. Next, you will add a water and bleach mixture to the concrete area. Allow it to sit and then rinse again.

The last measure is to add trisodium phosphate to your bleach mixture. Once you saturate the concrete area with this, it should kill any that remains. You can allow this to dry. This removal method should kill what exists and prevent any further outbreaks on the concrete. Read our full guide on how to remove black mold from concrete.

Black mold prevention tips

Some tips to prevent any further outbreaks include:

  • Finding the original cause of the growth and rectify it.
  • Ensure you have preformed proper removal.
  • Always try any damp areas and do not allow water to collect.
  • Always have proper ventilation in moisture-prone areas.
  • Keep an eye on indoor humidity levels.
  • Check basements, bathrooms, and kitchen sink areas for signs of water damage to prevent growth.

Consult a remediation professional

If you have tried at-home remedies for removal but do not feel confident that the issue has been resolved, never be afraid to contact the professionals! They will be more than happy to guide you and resolve your issue once and for all.