Why is My Wood Floor Turning Black?

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wood floor turning black

Hardwood flooring continues to be the most popular flooring option available. It not only adds beauty to your home but also adds value.

Which makes it a real bummer when you see that your floor is turning black or has black dots all over it. Luckily, in most cases, this is a problem you can fix.

If you’re wondering, “why is my wood flooring turning black” here are the top reasons and how to fix it.

Key Takeaways:

Your wood floor could be turning black due to either moisture damage or an adverse reaction to metal that may be resting on it. Excess moisture is treatable with hydrogen peroxide or a wood stain treater. Metal spots need tannin spot neutralizers, which you can treat and leave for an hour before wiping dry. In dire cases, you may need to refinish the wood.

Top Two Reason Your Wood Floor is Turning Black

There are two reasons your wood floors are turning black. First, there’s been moisture damage caused by a spill, urine, or flooding that has caused your wood floors to mold. Secondly, your floor has reacted to metal sitting on it. Either way, the affected floorboards should be treated or replaced.

In my years of experience, I’ve found that prevention is often the best cure when it comes to black spots on wood floors. Try to clean up any spills promptly. If you have pets, train them to do their business outside or in a designated area to avoid urine stains. And always use coasters or pads under metal objects to prevent black marks. Small efforts can go a long way in maintaining the beauty of your hardwood floor.

Why Your Wood Floor is Turning Black

Black Mold Spots in Your Floor from Water Damage

The most common reason for a hardwood floor to turn black is because it’s growing mold caused by excess moisture. You can confirm this if the black spots on your floor are in areas where there have been flooding, spills, or urine messes.

I can’t stress enough the importance of treating the black spot as soon as you notice it. Remember that time is of the essence. If left unattended, the black spots could spread, becoming harder and more costly to fix. In severe cases, they might permanently damage your floor.

There are a few ways you can go about removing black spots caused by excess moisture.

Here are two of the most popular:

Treat the spots with hydrogen peroxide – If you have light-colored flooring, using peroxide to bleach the stains is a viable choice. (However, before you do this, you need to do a spot check to ensure no bad reactions.)

To use this method, dab the black spots with a cloth soaked in hydrogen peroxide. Allow to dry and repeat as many times as necessary.

Use a wood stain treater – A product explicitly formulated for wood stains (especially those for urine) may be able to lift the black marks. A popular product to try is Nature’s Miracle Hardwood Floor Cleaner.

 For best results, simply follow the directions on the stain remover of your choice.

If you’re using a product for the first time, I highly recommend testing it on a small, hidden area of your floor before applying it to a more visible area. This way, you can see how the product works and how your floor reacts to it without risking damaging a prominent part of your floor.

Black Spots Caused By Metal

If you have oak floors, you may notice black spots where metal or water, even in small amounts, has come into contact with your floor. (Like metal table legs sitting in place for an extended time, for example.)

This happens because oak flooring is very tannic, and the metal and water cause a chemical reaction, creating black marks.

The good news is that this is a much better problem to have than black mold. The bad news is that mold caused by excess moisture is more prevalent.

How to treat black spots caused by metal:

If you think you’re dealing with black spots caused by a chemical reaction, you can treat it with a tannin spot neutralizer. To use a product like this, you’ll need to treat the area with the tannin neutralizer, let it sit for 60 minutes, and wipe dry. Afterward, you’ll need to reapply the topcoat to the places you’ve treated.

What to Do If You Can’t Get the Black Marks Out of Your Floor

If you tried treating the black marks on your floors with a stain remover or peroxide and didn’t have luck, your next best option is to replace those floorboards or sand out the stains and have those areas refinished.

If the stain is large, you may need to have your entire wood floors refinished.

Frequently Asked Questions

Does water stain hardwood floors?

Yes, water can stain hardwood floors. Even worse, if you see black on your hardwoods after they were exposed to moisture, you’re probably dealing with mold. 

What causes white spots on hardwood floors?

White spots on hardwood floors are usually caused by heat or by spilling a hot liquid on them. You may be able to remove these spots by dabbing them with hydrogen peroxide or using a wood stain remover.

How do you remove brown water stains from hardwood flooring?

You can remove brown water stains from your hardwood the same way you would with black stains. Start by treating the spots with hydrogen peroxide or a wood stain remover. If that doesn’t work, you’ll need to replace the boards with stains or sand and refinish them.


If you’re wondering why your wood floor is turning black, the most common answer is that moisture has seeped into your floor, causing black mold. However, if the black spots are small and still relatively new, you may be able to remove them with a stain remover or peroxide.

For larger, set in black spots, you may need to replace your flooring or have it refinished.

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Katie Barton lives with her husband and three daughters in an 1800’s style log cabin in southern Ohio. She thinks cleaning is relaxing and is considered the organizing go-to person by her family and friends. She runs the blog Cabin Lane where she shares about cleaning, decluttering, and minimalism. See full biography here.

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