Remove Old Set-In Pet Urine Stains (Dog or Cat) From Carpet
DISCLOSURE: Some of our articles may contain affiliate links. If you use these links to make a purchase, we may earn a commission (at no cost to you). Thanks for supporting us!
In this post, I’ll show you EXACTLY how to remove pet urine stains from carpet! This process will be broken down into two parts. In the first part, we will use a cleaning agent to try and remove the urine from the carpet.
If a yellow, brown, red, or other colour stain remains after completing part one, this is likely a set-in stain. In part 2 we'll go over a stain removal method that can be used to break down set-in urine stains.
Part 1 - Spot Removal (Get The Urine Out of The Carpet!)
Part one is simple - We have urine in our carpet so lets try to take the urine out of the carpet. To do this, we need a cleaning agent. There are many different types of cleaning agents (spotters) to choose from - all purpose spotters, off the shelf spotters, degreasers, alkaline cleaners, detergents, and many more.
When it comes to urine, vomit, feces, or really any biological stain, it is best to use an enzyme cleaner as a cleaning agent. If you are not able to use an enzyme cleaner, a general all purpose spotter will work as well (more about this in a bit).
Lets take a minute to discuss enzyme cleaners. Enzyme cleaners contain many types enzyme cultures that break down organic matter. If you have a old dried biological stain, an enzyme cleaner will seemingly digest the stain and break it up so it can be easily removed from the carpet.
Enzymes not only work great for getting gunk out of your carpet, they are also great for breaking down many types of unpleasant odours. When it comes to urine, most enzyme cleaning products contain an enzyme called urease, which breaks down urea molecules, the primary odour causing substance, in urine.
An alternative to using an enzyme cleaner would be to use an all purpose spotter. This could be an all purpose spotter from your local grocery store (SpotShot, Resolve, or Folex), or even one of the homemade mixtures noted below. Note: when using a store bought spotter, simply follow the directions on the bottle.
Zero residue homemade all purpose spotter recipes:
1) Mix 1 cup of water with 2 cups of 70% isopropyl alcohol.
2) Mix 1/2 cup of household ammonia, with 2 cups of water.
3) Pure cooking vinegar (5% - 7% acetic acid)
If you intend to use an enzyme cleaner, I highly recommend a product called BioKleen Bac-Out Stain & Odor Remover. I have been using this product for years, and it can remove really tough stains, and break down foul odours.
Now that you've got your cleaning agent (spotter) picked out, let's get to the cleaning!
IN THE DEMO, I'LL BE USING THE FOLLOWING PRODUCTS:
Step 1 - Apply the enzyme cleaning solution or cleaning agent of your choice liberally over the stained area.
Biokleen Bac-Out Stain + Odour Remover is my preferred enzyme cleaner.
If you are not able to use an enzyme cleaner, feel free to use one of the other homemade cleaning agents noted above.
Step 2 - Gently agitate the stained area using an old toothbrush or a soft bristled brush. Then allow the cleaning agent sit and dwell for 5 minutes minimum. The dwell time will allow the salts in the urine to dissolve. The dwell time is also important to allow the enzyme cultures time to break down the urea, which is the main odour causing molecule in urine.
If you are dealing with a pet urine situation where the urine odour is quite pungent, you may want to increase the enzyme dwell time.
RECOMMENDED: How to Remove Pet Urine Odours From Carpet
Step 3 - Extract the urine and cleaning solution from the carpet using a wet/dry vacuum. If you do not have a wet/dry vacuum, you can use a stack of white towels to absorb the cleaning solution and urine from the carpet. Simply place the a towel over the stain, apply pressure, and allow the moisture to transfer to the towel. Repeat with as many clean towels as necessary until the moisture stops transferring to the towel.
Step 4 (Optional) - Even though BioKleen Bac-Out does not require rinsing, per the manufacturer instructions, I find it to be a little soapy and sudsy, so I like to rinse the product out of the carpet using water. Spray the affected area liberally with tap water.
Step 5 (Optional) - After spraying the water over the affected areas, use a wet dry vacuum to extract the water and cleaning agent residue from the carpet. Once again, if you are not using a wet/dry vacuum, you can use a stack of white towels to absorb the water and residue from the carpet. Simply place the a towel over the damp area, apply pressure, and repeat with clean towels until the moisture stops transferring to the towel.
If using a homemade cleaning agent that is made with vinegar, household ammonia, or isopropyl alcohol, rinsing is not required because these cleaning agents evaporate and leave zero residue.
Step 6 - We've removed as much of the urine from the carpet as possible in Part one - what remains is a set in stain. Let's discuss how to remove set-in urine stains in part 2!
Part 2 - Stain Removal (Remove Set-In Urine Stains)
If you are dealing with a dried, or an older urine stain, the pigments from the urine may have bonded to the carpet fibers resulting in a set-in stain. To remove a set-in urine stain we need to use a stain removal method. Stain removal methods are essentially chemical reactions that are used to break down organic pigments that are permanently stuck to the carpet fibers.
In this case, we are trying to break down urine pigments, known as urobilin pigments, that are permanently stuck to the carpet fibers. The process is simple - there are unwanted yellow pigments stuck to the outer surface of the carpet, so we use a chemical reaction to break the pigment (destroy the pigment), causing it to loses its colour properties.
When removing set-in urine stains, I always use good old 6% hydrogen peroxide. Hydrogen peroxide is a professional carpet cleaners best friend and is a key ingredient for stain removal.
Hydrogen peroxide is a colour safe bleach meaning that it is strong enough to break down many organic pigments, but it is not strong enough to break down the synthetic dyes that carpet manufacturers use to give our carpets colour.
When selecting a hydrogen peroxide product, it is important to use a 6% or a 20 Volume grade. I always use salon grade hydrogen peroxide, known as 20 Volume Clear Developer.
Now that we've discussed the theory, let's get to the cleaning!
IN THE DEMO, I'LL BE USING THE FOLLOWING PRODUCTS:
Step 1 - Dry the carpet as much as possible before starting Part 2. The carpet does not have to be completely dry but too much moisture will dilute the hydrogen peroxide and cause it to be less effective as a stain remover.
Using a spray bottle filled with 20 Volume Clear Developer (6% hydrogen peroxide), liberally spray the stained area.
Step 2 - Using a second spray bottle filled with household ammonia, or clear ammonia, lightly spray the stained area, maintaining a ratio of 3 parts hydrogen peroxide to one part ammonia. The ammonia is an important ingredient because it activates the hydrogen peroxide.
Hydrogen peroxide and ammonia should be kept in separate containers, only mix them when spraying them into the carpet.
Step 3 - Cover the stained area with a piece of plastic wrap. The plastic wrap is important because it prevents the ammonia from evaporating. If left uncovered, the ammonia will evaporate very quickly and the stain removal reaction will nearly come to a stop.
Step 4 - Place a pot of hot tap water on top of the stain. The water temperature can range anywhere from 40°C (104°F) to 70°C (158°F). Do not go above 70°C, as these hotter temperatures could damage your carpet. Allow the pot to sit in place for 30 minutes.
During the 30 minutes, the hydrogen peroxide will break down the unwanted urine pigments that are stuck in the carpet.
Step 5 - After 30 minutes, we can see that the stain has been 100% broken down. Use a stack of dry white towels to absorb the remaining liquid from the carpet.
Hydrogen peroxide and ammonia completely evaporate, leaving zero residue behind in the carpet.
Step 6 - Here is the final result! Be sure to check out the video instructions below.
How to Remove Pet Urine Stains (Dog or Cat) From Carpet - Video Instructions
No Dilution Needed: Do not dilute the 6% hydrogen peroxide or household ammonia. Use them as-is for optimal results.
Handle Delicates with Care: Avoid using these methods on delicate materials such as wool, silk, or other natural fibers. For these items, it's best to consult a professional cleaner.
Test in an Inconspicuous Area: Always test any stain removal method in an inconspicuous area on your carpet before full application. This can be done on a scrap piece of carpet or in the corner of a closet.
Avoid Direct Sunlight: Stain removal should not be conducted in direct sunlight. Close the blinds to prevent exposure to harsh sunlight when using hydrogen peroxide.
Ventilation for Ammonia: Household ammonia can have a strong odor. We recommend opening a window to enhance ventilation and reduce the odor. Rest assured, the ammonia odor dissipates completely as the carpet dries.
Safety First: During spot and stain removal, it's best to keep your children and pets in another room to ensure their safety.
Protect Your Skin: Always wear plastic gloves to shield your skin when handling hydrogen peroxide.
Never Mix with Bleach: Never mix household ammonia cleaner with bleach. This combination produces a toxic gas called chloramine, which can lead to shortness of breath and chest pain.
Use at Your Own Risk: These methods are offered for informational purposes, and we recommend using them at your own risk.