Removing black urine stains from hardwood floors

Our beloved pets are likely to have accidents from time to time. Especially if you’re toilet training a puppy or caring for an elderly pet.

Unfortunately, their little accidents can leave unsightly stains on hardwood flooring. 

If pet urine isn’t cleaned up immediately, it will soak into hardwood flooring. Once the acidity of pet urine penetrates the wood a black stain will form.

You may also notice warps or splitting of the wood due to the excess liquid. Left untreated, the scent of urine will encourage pets to repeat accidents in the same spot. 

You can remove black urine stains from hardwood floors using either:

• hydrogen peroxide
• white vinegar and grapefruit oil
• bicarbonate of soda (baking soda)
• enzymatic cleaner
• commercial cleaners

There may be affiliate links in this article. You can read more about this in my disclosure.

Why do urine stains turn black on hardwood floors?

Pet urine is often acidic and may break down the protective finish on hardwood flooring.

Once the urine has penetrated through the hardwood finish, the stain will turn black. It’s best to clean urine immediately to avoid staining the wood.

If a black stain has formed, don’t panic. You can return your hardwood flooring to its former glory by using one of the following methods.

Follow cleaning with a hardwood sealant or penetrating oil to protect your flooring.

Hydrogen peroxide 

Hydrogen peroxide is a chemical that is often used as a bleaching agent or as an antiseptic. It can be used to disinfect and deodorise pet urine stains.

Deodorising will help to prevent further accidents in the same spot. 

You can buy hydrogen peroxide at most high-street chemists or in bulk quantities on Amazon.

You’ll need 3% concentration for use on hardwood flooring. Stronger solutions may bleach the wood a lighter colour. 

If you already have a higher strength hydrogen peroxide at home, this can be diluted with water. To work out the water-to-peroxide ratio needed, you can use the Hydrogen Peroxide Dilution Calculator by Happy Hydro Farm.

For this method, you’ll need hydrogen peroxide, a spray bottle, rubber gloves, and a soft cloths or a towel.

1. If needed, dilute the hydrogen peroxide with water to make a 3% concentration 
2. Pour the 3% peroxide solution into a spray bottle
3. Spray evenly over the stain
4. Leave to soak for 30 minutes
5. Wipe with a clean damp soft cloth or towel

Always protect your skin with rubber gloves when using hydrogen peroxide.

White vinegar and grapefruit essential oil

Grapefruit essential oil has antiseptic qualities. When paired with the acidity of white vinegar, it can make a powerful stain remover.

Plus, the grapefruit scent will cover up the unpleasant smell of white vinegar. 

Grapefruit oil also acts as a natural repellant for cats and dogs. By applying it to the stained area, you can prevent future accidents in the same place.

You can find grapefruit essential oil and white vinegar for sale on Amazon. Make sure to buy pure grapefruit essential oil with no added ingredients.

For this method, you’ll need white vinegar, grapefruit essential oil, water, a spray bottle, and a soft cloth.

1. Mix together a 1:1 ratio of white vinegar and water in a spray bottle 
2. Add a few drops of grapefruit essential oil to the spray bottle
3. Spray the mixture onto the stain and scrub with a soft cloth
4. Wipe clean with a clean soft damp cloth

Bicarbonate of soda

Bicarbonate of soda (baking soda) is a safe, eco-friendly, and affordable household cleaner.

When used on pet urine stains it will break down the acidity, draw out moisture, and deodorise the area. You can purchase bicarbonate of soda at the supermarket or in bulk quantities on Amazon.

You will need bicarbonate of soda, water, and a soft cloth for this method.

1. Sprinkle bicarbonate of soda evenly across the stain
2. Leave to sit for one hour
3. Remove the bicarbonate of soda with a soft damp cloth

If this doesn’t work, you can try making a bicarbonate of soda paste. Simply mix water and bicarbonate together until it forms the consistency of toothpaste.

Spread a thin layer evenly across the stain and leave for one hour. Wipe away with a clean soft damp cloth and dry with a clean towel.

Enzymatic cleaner

Enzymatic cleaners can break down organic matter like urine, blood, and sweat. They are often used to disinfect medical equipment contaminated by bodily fluids. 

Most surfaces, including hardwood flooring, are safe to use with enzymatic cleaners. Still, it’s best to test any new cleaning product on a small inconspicuous area before use.

You can make your own DIY enzymatic cleaner at home. Bear in mind that it needs to ferment to be effective, so it will take a month to make.

To make DIY enzymatic cleaner, you’ll need an old soda bottle, sugar, yeast, citrus peel, and water.

1. Chop 300g of lemon or other citrus fruit rind into small pieces
2. Place the chopped citrus peel into a clean soda bottle
3. Add 100g of brown or white sugar and one teaspoon of yeast
4. Pour in one litre of filtered water
5. Shake the bottle well for 30 seconds to mix
6. Unscrew the bottle to let out any gases that have built up before replacing the lid tightly
7. Write the date on a label and attach it to the bottle
8. Leave to ferment for one month in a warm place (above 35 C for best results)

During fermentation, the yeast will convert the sugar into alcohol and carbon dioxide. For the first two weeks, it’s important to unscrew the bottle lid three times a day to release the build-up of carbon dioxide.

Otherwise, your soda bottle may explode from the pressure. After two weeks, you will only need to vent your bottle once a day as most of the sugar will have been converted.

Once fermented you will need to strain the liquid through a sieve to remove the citrus peels. Store your DIY enzymatic cleaner in an airtight container. 

To clean urine stains on hardwood floors, you can pour the cleaner straight into a spray bottle. Spray the cleaner onto the urine stain and rub the area with a soft cloth.

Then wipe away with a soft damp cloth and dry with a clean towel

Commercial cleaners

You can also buy ready-made cleaners designed specifically to target pet urine stains. Commercial pet stain removers can be a more convenient way of cleaning than DIY methods but will usually be more expensive. 

Your local pet shop will have a range of pet stain removers to choose from. When shopping for a pet stain remover, make sure the product is suitable for use on hard floors.

For a ready-made enzymatic cleaner, try the Extreme Pet Stain and Odour Remover by Simple Solution. It’s non-toxic and designed specifically for hard surfaces like hardwood flooring.

Protecting hardwood floors from future accidents

Whilst it’s possible to remove black urine stains from hardwood flooring, it’s easier to prevent them.

If your pet is prone to little accidents, invest in a box of puppy training pads. Simple Solution Dog and Puppy Training Pads are designed to absorb up to six cups of liquid whilst also neutralising odours.

There are reusable pads available for those worried about the environmental impact of disposables. 

To protect your hardwood flooring further, you can apply a hardwood sealant. This provides an extra barrier and extends the time it takes for pet urine to penetrate the wood.

Sealants will usually need to be reapplied every two to five years. When applying sealant, make sure to open any windows as the smell can be quite strong.

Before using a sealant, it’s important to be aware that sealants can change the colour and shine of your hardwood flooring. 

You may prefer to use a penetrating oil like Furniture Clinic’s Wood Danish Oil. Unlike sealants, penetrating oils are designed to soak deep into the wood for better protection.

People tend to find penetrating oils leave a more natural finish when compared to hardwood sealants. This is likely because the oil soaks into the wood, whilst the sealant sits on top.

For penetrating oils to work best, use them every time you clean your hardwood floors. 

Last update on 2023-06-04 / Affiliate links / Images from Amazon Product Advertising API