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There is nothing worse than trying to get rid of the foul urine smell from pets, dogs, and cats out of the concrete of your garage floor or basement. It seems like no matter how much you clean, the smell just won’t go away. We will cover the best methods for getting rid of pet urine odor in your concrete as well as how to seal the garage floor or basement to block any odors that may remain from concrete with particularly heavy urine issues.
Most concrete with pet urine odor needs to be treated in a two-stage process. Sometimes it may even require an additional stage depending on the type of urine odor remover or pet enzymatic product that is used. It also helps to use a wet vac if you have one, particularly if you have a basement with urine odors and no drain available. Carpet cleaners can work in a pinch for vacuuming up liquids as well.
Pet urine odor and stains won’t go away with normal cleaning
Our guess is that you may have already tried cleaning the urine stains to remove the odor in the concrete and without good results. The stain may or may not be gone, but the smell remains. That is why it’s important to learn why the urine odor still exists and why conventional cleaning methods do not work. Doing so can save you some time and expense.
Concrete is actually porous like a sponge. If liquid is allowed to sit for a period of time, it will absorb most anything. This is why it’s hard to get stains out of concrete.
When urine is introduced to concrete and allowed to dry, the uric acid crystals present in urine bond tightly to the concrete. Unfortunately, these crystals form deep within the pores and capillaries of the concrete since the urine was allowed to soak – sometimes multiple times for days or even months.
Despite numerous cleanings, uric acid crystals are insoluble and will not bind with regular soaps and other cleaning agents. Thus, the crystals stay attached to the concrete and the smell remains. The smell may dissipate temporarily after a good cleaning, but as soon as any type of moisture is introduced again, it can come back just as strong as before. Basements can be particularly susceptible to this.
The reason for the smell returning is that uric acid crystals will release a gas as soon as moisture (humidity for example) is introduced. This gas is what creates the pungently strong odor. The best way to stop the smell is to use an enzymatic cleaner that attacks and breaks down the uric acid crystals and separates them from the concrete.
In order to get the best results from an enzymatic pet urine cleaner, there are a couple of important steps that must be taken beforehand. First, you must identify the exact areas in the concrete affected by the urine. Next, it’s important to properly clean the area to rid the concrete of bacteria and other residual urine elements. Contrary to popular belief, most enzymatic cleaners do not remove bacteria.
How to identify urine odor stains in concrete
Many times the source of pet urine odor can easily be identified, such as an area where pets where kept in a pen. However, sometimes it may not be so easy to detect.
This is often the case for people who have moved into a home that previously had pets, only to find that the garage floor reeks of a foul urine smell. Stains may have previously been cleaned thus hiding the source of the odor.
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One tool that does a good job at identifying pet urine is a U.V. light or black light. These here from Amazon do a good job.
Close the doors and then turn on the black light. Hold it no more than three feet off the concrete as you scan the floor in sections. Old urine stains will stand out as blue, green, or yellow markings on the concrete.
We like to encircle the far outside area with arrows pointing towards the urine stain. Chalk works well for this providing you don’t get it wet. Be sure to check the first two feet of your walls from the floor up as well. Sometimes pets will urinate on the walls which will require removing and replacing the affected section of drywall to get rid of the smell.
If for some reason the U.V. light does not reveal any stains, the old standby that will work is your nose. This takes longer but it is effective. Open the doors to air out the garage and get rid of the immediate smell. After that, get down on your hands and knees and start sniffing. Trust us; you will know when you find it!
Clean the pet urine stains with TSP
Once you know where the urine stains are, the first step will be to scrub the area with a strong solution of ½ cup TSP (Trisodium Phosphate) to 1 gallon of hot water. TSP mixed at this ratio is very strong. Gloves and eye protection should be worn for safety.
What the TSP does is remove all the bacteria, most if not all of the stain, as well as remove other residue left from the urine. It will leave only the uric acid crystals behind. This will allow the enzymatic pet urine cleaner to work faster and more efficiently at removing the uric acid crystals.
Pour the hot TSP solution onto the urine stain or identified area and scrub it with a short bristled nylon brush. A deck brush works well for this. Make sure that you keep the area wet for at least 10 minutes or more to allow it to soak into the concrete. The solution will follow the same paths as the urine did and will need some time to work its way down into the concrete.
Do not be surprised if the smell increases as you soak the concrete. It is a combination of urine residue and the uric acid crystals reacting and releasing gas from contact with the water.
Once the area has been scrubbed and allowed to soak long enough, pour clean hot water over the treated area again and then vacuum up the water with the wet/vac. Carpet cleaners will work for this as well. You will want to do this at least twice. For heavily treated and soiled areas, three times would be better.
This hot water rinsing will remove the TSP solution and help to suck up any remaining urine residue that is in the concrete. Treat any additional areas in the same fashion (scrub, soak, rinse) and then allow the concrete to dry at least overnight. 24 hours or more is best. Pet urine enzymatic cleaners work best when the concrete is completely dry before treatment.
As a note, the TSP may create a whiter looking area or areas on your garage floor since it is getting the concrete very clean. If that is the case, you may want to scrub the rest of your concrete after you are done with the same TSP solution in order to achieve a more consistent (and clean) look to the floor.
Using a hose with a high pressure nozzle works fine for this in order to speed up the rinsing process. You are just removing dirt at this point and not sucking up urine residue. We have more tips for cleaning a garage floor here.
Apply pet urine enzymatic cleaner to concrete
Pet enzymatic cleaners work by using bacteria (the good kind) to digest malodors, waste, and stains. These bacteria produce enzymes that break down the molecules of the uric acid crystals into smaller bits. This allows the bacteria to digest the smaller bits and break them down into the two basic components of carbon dioxide and water.
Because you are working with concrete and not carpet, we suggest using a product that is available in a concentrate or gallon jugs and not something that comes in a spray bottle. Unlike carpet, you will need to use liberal amounts of the cleaner.
The reason for this is that most enzymatic products need some sort of an exchange with air. Since most of the uric acid crystals are deep in the concrete, it takes more time for the required air exchange. It will also take time for the concrete to absorb the enzymatic cleaner. Since some of the cleaner will evaporate on the surface as it soaks in, more will need to be used.
A product we can recommend that has worked wonders for us in the past is Rocco & Roxie Professional Strength Stain and Odor Eliminator.
It has stellar reviews and we know of more than one kennel that uses this as their go-to odor eliminator. Further more, it’s available in gallon jugs and does an excellent job when given time to work. You can find it here on Amazon.
There are many other products with good reviews that you can shop for here if you prefer. We recommend staying away from the products that require mixing with a carpet shampoo as these will not be as effective on concrete.
Be sure to follow the directions of the product you choose. Pour it onto the stained area and then start scrubbing it in with a deck brush. Keep it wet for at least 10 minutes or more. You want the concrete to absorb as much of the solution as possible.
For the best results, cover the wet area with a cheap painter’s tarp to help avoid evaporation of the solution. This will give it more time to soak into the concrete. Rinsing is not required. The enzymatic cleaner will break down the uric acid crystals into carbon dioxide and water which will dissipate on its own.
Particularly bad smelling areas may require multiple treatments. This is because it will take time and more enzymatic cleaner to soak into the concrete and do its work. Remember, you may be dealing with an area that allowed the concrete to soak in urine for weeks or months.
Sealing concrete from pet urine odors
On rare occasions it may require sealing the concrete to prevent any residual pet urine odor from working its way back to the surface. Sometimes people want to do this regardless of the fact that the odor is gone, they just don’t want to take the chance of it returning.
The only type of sealer that will work is a garage floor coating. The reason is that garage floor coatings are film forming and do not breathe. They will block odor molecules from transferring through the coating. Acrylic sealers and penetrating sealers will not work. They are breathable and will allow the odor molecules to pass through.
Applying a garage floor coating requires grinding or acid etching the concrete before application. If you know that you will be applying a coating before you treat your garage for pet urine odor, we recommend treating the concrete after you grind or acid etch.
The concrete prep process will open the pores of the concrete and allow pet enzymatic cleaners to be absorbed into the concrete more easily. It will allow slightly more air transfer as well. The result will be a quicker and more effective use of the cleaner.
Once the coating is applied and has cured, it should effectively block any odors that remain in the concrete.
I have no windows that open in my basement. What do I need to be safe to use this?
Hi Nancy. You will be safe as is. There are no fumes to worry about with TSP or Rocco & Roxie.
I purchased this product because of the positive responses. I will have to tell you…I choked because of the off gassing when I sprayed this onto 10 year old concrete pee (we purchased an older home and the previous owner’s ‘crated’ 3 dogs in the laundry room). We moved the laundry and are hoping to turn the space into a Butler’s pantry if I can get the smell out. I truly think the smell or ‘fume’s’ is due to the product doing it’s job….will update after 2 treatments! Praying this works!!
Thanks for the feedback, T. You did clean the area first with TSP, correct?
We did….and the second application to the concrete/seal plate seems to have done the trick! The smell was minimal on the second application and after 2 days we can’t detect any odors. Very happy campers!
Great to hear, Tonya!
Tonya – what products did you buy/use? TSP and Rocco & Roxie? I too have concrete basement w/ cat urine that been sitting for years.
Hi Brandon. Tonya used both the TSP and Rocco & Roxie. Also, be sure to check your walls. Cats have a nasty habit of spraying walls and you may need to replace some drywall.
We ripped up the carpet in my spare bedroom and our cats have decided to pee on the concrete. I was trying to see if this would work even though it is inside the house? We want to put wood floors down after the concrete is cleaned. Thanks!!
Hi Amanda. Yes, it will indoors as well as out. Just clean the concrete well with the TSP solution first. Rinse and use a shop wet vac to get the residue. It will help to cover the odor removing solution with plastic while it does it’s job.
The floors in my house are all concrete. There are dog urine stains. Long story,, I am not able to do your recommend cleaning. There us to much floor. Do have any other suggestions?
Hi Elvin. We recommend doing it in sections or room by room. You don’t have to do the entire house at once. You won’t get rid of the odor if you don’t clean.
Thank you
Thank you for your article, very helpful. I am dealing with a home on concrete slab. Tenant had 30 unsupervised cats. Urine and feces everywhere! We have removed carpet, pad and scrubbed concrete with alkaline cleaner, acid rinse and then xcide odor remover. Smell is no better. I will try tsp and Rocco enzyme. Any recommendation for sealer? I do want to use epoxy for health reasons. Thanks again
Hi Susan. Any water-based or 100% solids epoxy will seal the concrete since the coating does not breathe. Water-based and 100% solids epoxy are low to no VOC products.
Hi there, tsp is banned in nys. Could I use tsp-pf? Or is there something better than that. Also, what are your thoughts on odoban? Thanks!
Hi Michaela. It’s the phosphate in TSP that kills the bacteria. So phosphate free TSP will not work. We suggest using Simple Green d Pro 3 Plus for the initial cleaning and killing of the bacteria. Make sure to let it soak in and dwell for a while so that it can get down into the concrete. It’s the dwell time that kills the bacteria. After it has dried thoroughly, you can then apply the Rocco & Roxie.
Shea, I read that Borax will be an effective substitute for TSP in killing the bacteria. Do you agree? Thank you for this wonderful article.
Hi Dona. It’s not as potent a solution as TSP. However, it may work fine if allowed to dwell and soak into the concrete. Try to keep the concrete wet with the borax solution by covering it with plastic such as trash bags. This will slow down evaporation and allow it to stay wet longer and soak in to do its work.
Thank you Shea, will use the plastic bags tip.
Shea, I’m glad I found your article. It was very informative. I want to paint the concrete in my house after cleaning. Do I need to seal first to remove the smell and then paint or can I paint and then seal. Thanks
Hi Anne. What do you mean by paint exactly? Are referring to a durable resinous coating (not paint) or actual latex acrylic paint? And is this for inside the actual house or in the garage?
Painting a concrete living room floor inside the house using a latex paint.
OK, thanks for clarifying that. The only type of product you can put down that would seal-in any odors would be a non-breathing film forming coating. These are materials such as epoxy, polyurea, polaspartic, and etc. Penetrating sealers that are applied to bare concrete are breathable and will allow odor molecules to pass through. Paint is not a sealer and is breathable as well. Your best bet is to just make sure that you completely eliminate the odors before you paint. The other option would be to rough up the surface of the paint with 120 grit sandpaper after it has dried and then apply a clear epoxy or water-based polyurethane for concrete (not wood floors) to the paint.
Thank you.
Thanks for this great article.
My area with urine odor is a walkway with plants beside it. It will be hard to saturate the area without some solution going into the dirt. Will the TSP damage the plants?
Thanks
Hi Sandra. If you can limit the amount that gets in the plant beds you will be better off. TSP is very alkaline and can do some damage if it comes in contact with the plants or the plant bed gets saturated. It would be even better if you could dig a small trench next the walkway where any runoff will go. This will prevent it from freely spreading into plant beds. Saturate your plants with fresh water just before you start.
We installed a red brick patio and in the winter my dog had apparently used it to go pee (cold feet I’m sure) but you can smell it now and Id like to try this method but I want to make sure it work ruin the color of the brick. Why do you suggest?
Hi Nicole. I can’t say for sure that it would not have any effect on the brick. What I suggest you do is test a very small area with both the TSP and the odor eliminator in order to verify that you will not experience any color change.
If the basement floor has been cleaned with bleach twice is there a need to still use tsp to kill the bacteria before using the enzyme cleaner?
Hi Susan. If the bleach was allowed to dwell long enough to get down in the pores to do its job, then it should be OK. Bleach works well on hard, non porous surfaces, but it can take some time with porous surfaces such as concrete.
Thank you for the article. Sealer/primers like KILZ and Zinsser BIN are advertised as effective pet odor blocking sealants able to be used on indoor concrete. Would these be suitable as a last step indoors before new flooring is installed? Thanks!
Hi Aaron. Those products have been known to work, however, unlike a resinous coating (epoxy for example) they still breathe. If the concrete underneath ever gets damp from ground moisture, the odor molecules that are activated can still come through the paint.
Excellent article! Thank you for posting it.
Where can I buy TSP?
Hi Lorena. You can usually find it at your local home improvement centers or hardware stores.
I have a carport that was converted to a bedroom. The only had a dog and I smell urine when I go in the room. We have rmoved the carpet and plan on installing a vapor barrier before we install vinly palnk flooring. Will this eliminate the odor or do I need to clen first?
Hi Cindy. We highly recommend cleaning and deodorizing the best you can before installing the new flooring. Odors have a tendency of eventually finding their way around the edges of vapor barriers and announce their presence to the unsuspecting nose when the proper conditions exist.
Am I understanding correctly that since I plan on using a garage floor sealant on my concrete sub-level living room floor, that it is okay to use muriatic acid to etch the concrete PRIOR to deep cleaning with the TSP? Yes? No? Explain further the etching process. Thanks!
Hello Cindy. Yes, as the article states, it works best to etch first and then use the TSP when trying to kill off the bacteria. This allows the TSP to soak in more and get better dwell time to do its work. Once the concrete is neutralized and completely dries (not just the surface), you can then apply Rocco & Roxie or similar product. However, if this is an interior living space and not a garage, then you do not want to use muriatic acid. The fumes of a muriatic acid solution require good ventilation and can cause damage to interior metal furniture, appliances, and etc. We suggest using a good etching alternative such as Acid Magic. Also, if you plan to seal the concrete in order to prevent odors from passing through, it will require a 2-part epoxy coating or similar product.
How hot temperature-wise should the solution water and hot rinse water be for best performance?
Thank you!
Hi Cindy. I’m assuming you are referring to the TSP solution. You want to get it real warm to hot, but not so hot that it’s difficult to work with.
Can you put laminate flooring over water-based polyurethane? We are in the process of cleaning a very heavy cat urine scent. It’s in the downstairs bathroom and we don’t want to leave the floor as cement. We pulled up the old laminate to day and it was horrible.
Hi Teara. Yes, laminate flooring is free-floating so it can be installed over a coating. Just make sure remove as much of the smell as you can first with the above steps. Just makes sure that the polyurethane coating you plan to apply is for bare concrete floors and not for wood floors and furniture. The correct type of polyurethane will not be found in home improvement stores and usually has to be purchased online from a concrete coating vendor.
A very old sewer drain on top of the soil in the crawl space under my house corroded. The pipe was replaced but the urine smell lingers and I can smell it. What could I use for the soil around the new PVC?
Hi Joseph. Treating soil is different than concrete. Most people eliminate or reduce odors in soil by spreading a layer of lime on the area and then gently soaking it by sprinkling water on it so the solution can penetrate. It may take a couple applications.
How long does the product smell stay strong? I want to put Kilz Restoration on top of it prior to laying carpet . How long should I wait to paint? I treated the cement floor this morning and product smell is still quite strong tonight with fans and good ventilation. I used half of the big bottle on a 300sq ft room and just let it sit and slowly dry. I did not have urine smells but the odor of a sick and dying kitty being treated with very stinky medications. . I had my carpet covered with plastic and absorbent pads but the dying cat odor infiltrated all the textiles which I had to remove. I pulled the carpet and pad and have treated the concrete. How long before the product smell dissipates?
Hi Denise. An enzymatic odor remover needs time to work and break down the molecules and digest the waste. It’s not something you apply and the smell goes immediately away. It can take up to a few days.
We are doing a basement storage room floor. I did 4 tsp scrub/water rinse… I plan to etch then do the Rocco stuff (I got from your link Thx). How long do you recommend between etch and rocco and then rocco and garage floor paint? The etch we got says to wait 4 hour to overnight from etching to painting but we plan to add the rocco step as there have been mice in the past and we are bringing our cats in so we want to make sure nothing there… we have not noticed any smells in the area but there was lots of mice poop and a dead mouse.
Oh and thanks for your article… super helpful.
Hi Cassie. In order for the odor eliminator to do its job, it’s imperative that the concrete be completely dry. That means it has to be dry within the concrete as well as on the surface. With all the liquids that have been introduced to the slab, we suggest letting it dry for at least 48 hours. Basements floors typically like to hold moisture due to the closed in atmosphere. It would help to run a fan over the floor to facilitate with the drying process.
Hi! Thanks for this super-informative article! Our dining room floor is currently bare, unsealed concrete and our geriatric dog has been peeing on it for months— we clean it but the odor always remains. We are planning to seal it after we follow your advice, so to clarify the steps:
1. Etch with Acid Magic (due to it being an interior floor)
2. Scrub with TSP solution/rinse (2-3 times)
3. Allow area to dry thoroughly (24-48 hours)
4. Apply Rocco & Roxie, saturate, cover with plastic, allow to soak in
5. Once dry, seal with epoxy
Do you have an epoxy product you’d recommend?
Thanks again for the help!!!
Hi Joelle. You have the steps correct. In regards to the epoxy, you will want to use a water-based epoxy or a 100% solids epoxy. Neither have VOC’s to worry about. Solvent-based epoxy will produce too much of an odor that will linger for days inside since it will not have the type of ventilation that a garage does. Examples of a water-based product would be Rust-Oleum EpoxyShield. RockSolid is a more durable coating and will do well for indoors also.
Hi, I was just at the hardware store looking for a 100% epoxy concrete sealer. Everything says it is acrylic. What should I be looking for on the can to ensure it is the proper concrete sealer? Thanks!
Hi Adam. You will not find 100% solids epoxy coatings from a hardware store or your local home improvement center. They only carry residential quality coatings. Examples are your low solids water-based epoxy kits (Rust-Oleum for example) or 1-part epoxy paint which is acrylic concrete paint fortified with a little bit of epoxy resin. You need to purchase it from vendors online that specialize in concrete coatings. As an example, we have a list of our sponsors in this article here, many of which carry this type of product. They are not your only choice, but we know from experience that they carry commercial quality products. What is your ultimate goal for the coating and what are you planning on using for?
Thanks for the reply. We had a cat that peed on our mudroom floor. We thought we got all the stains out but kept smelling the urine on humid days. We finally ripped out all of the tile and the first little bit of drywall and have begun the cleaning process. Looks like the cat was going where we couldn’t see. We started with the TSP solution, and next the enzyme. We want to seal the concrete now before we put new flooring down. As for the 2x4s that got damaged, we will have to find another solution (we can’t take them out as they are structural). We don’t have the money to redo the slab or have someone redo the support studs so we have to try and make-do. We will clean and seal the best we can and then hopefully it is minimized at least on the humid days.
OK, that helps. If it’s for a room that only sees foot traffic, then one of the 2-part residential quality epoxy products would work to seal the concrete. Rust-Oleum EpoxyShield water-based or RockSolid are examples. Of the two, RockSolid it tougher and has a glossier finish. Both will be less expensive than a 100% solids. Of course, you can still use 100% solids epoxy if you like. For the wood studs, we suggest using something such as Kilz to seal in the odor. This is an example here.
Thank you so much!
I have always use enzyme formula whenever my pet peed on the carpet and it works well, but did that work for the CONCRETE or the floor under the carpet?
Hi Heather. No, treating the carpet will not have any effect on the concrete or subsequent flooring under the carpet. You have to treat each type of flooring separately.
Hi! Is there an epoxy sealer that you would recommend that is reasonably priced? Everything that I’m seeing is about $75-$175 for a kit. We are renovating our basement and the cement gets a smell when it gets wet. Once we clean and seal it we will be recovering the cement with carpet and Vinyl Laminate Plank flooring so we don’t need the fancy Rust-Oleum Epoxy Shield kit or RockSolid which seems to be used for garage floors to make them look nice. Is there a plain and simple epoxy that is cheaper since it will just be covered up anyways? If you could include links to your recommendations that would be fantastic!
Thanks so much for all the info!
Hi Alisha. Shop Valspar, Quikrete, EpoxyShield, or H&C Shield-Crete epoxy. These are all examples of the least expensive epoxy coatings your can find. This one from Amazon is an example. These are the cheap, residential quality epoxy coatings. You will not find anything less expensive because it does not exist. Epoxy is a 2-part thermosetting coating (not paint) and can’t be manufactured at $30 a gallon like paint is.
Shea,
Do you have an email that I can reach you to ask a few questions?
Thanks
Hello PJ. You can reach us via email using the Contact button at the bottom of the website page or email us directly at [email protected]
Is there a temperature range that is best to perform the applications? Also, does the hot water rinse of the TSP solution need to be vacuumed up rather than just rinsed? Thank you.
Hi Laura. There really isn’t an optimal temperature range. However, lower humidity is better than higher humidity when using the TSP solution to clean with. The rinse water of the TSP solution does not have to be pulled up with a wet vac. It can just be rinsed clean.
Hi,
We had an odor and fire restoration company work on the concrete basement floor (assuming cat urine allowed to sit on floors forever from previous owner) but the smell is still awful. Not sure what treatment they used but can I go ahead and do the epoxy seal without more cleaning first, to seal out the odor? It’s been raining for three days and it’s so bad you can’t breathe in the house. It’s usually more tolerable when the laminate floors were in (but still had), which is why we pulled them up to try to find the source.
Hi Samantha. Basements are tricky when it comes to applying an epoxy coating. Epoxy is a non breathable coating which is why it works well at blocking odors. However, basements typically have issues with moisture vapor since the concrete is below grade. Unless vapor barriers where installed before the concrete was poured, the concrete will absorb moisture from the ground and transmit that moisture through the concrete. That is why many basements are notoriously damp or have a musty smell. If epoxy is applied to concrete in a basement that has moisture vapor issues, it will delaminate and peel up after a period of time due to the amount of moisture that collects underneath the coating. It will actually cause the concrete directly under the coating to deteriorate. If the smell is worse when it rains, it mostly likely is due to moisture that is coming up through the concrete and causing the uric acid crystals to release the smelly gas. What you need to do is conduct a proper moisture test on the concrete floor when it’s damp or raining outside. This will help to determine if you can apply a coating or not. Out of curiosity, were the walls of the basement checked for urine? Cats are known for spraying on the walls. All the cleaning on the floor will not help if the walls are saturated with urine.
My question on the TSP and Rocco & Roxie. My cat’s litter box is in an unfinished part of my utility room. It contains our A/C, furnace, and gas water heater. Are these products safe to use around that area? Also, can I apply a coat of Kilz primer after it’s done to seal it?
Hi NP. Yes, they are safe to use in that area. If you use Kilz, we suggest this one here.