How To Get Urine Odor Out Of Concrete

How To Get Urine Odor Out Of Concrete

Can you please tell me more about the odor neutralizer? I am working with concrete that has been used in a dog day care / kennel for a couple of years. So far I have tried a degreaser/cleaner, enzymes (which included covering the floor with plastic for 24 hours to keep it wet), white vinegar, a high-tech odor neutralizer, and finally bleach, both straight and diluted. I have power-washed at the start, and again after each of these treatments. The bad odor has been reduced but it is still present.

Thanks for asking. Concrete is porous so what you have is a situation where dog urine has been soaking into the porous surface (it sounds like continuously) for a couple years. At least some of the products you have used are working.

The enzymes work by digesting the urine residue. The reason you keep them wet its two-fold.

  • One: They have to be wet to be active. When they dry they do nothing.
  • Two: To get them to soak into the concrete far enough to reach the urine, which would be in pretty deep.

Bleach uses oxygen to break down the urine. It will work also if it can reach the urine in enough concentration and for a long enough time to work (which for oxygen is fast). Washing is good and it will remove the urine it can get to. You do need to be careful with power washing though because it can drive the urine even deeper into the concrete depending on how you do it.

Neutralizer you asked about also has to come in contact with the urine to change the molecules. So your challenge is to get one of these (a good product) deep enough into the concrete. Where the urine is after a couple years of soaking in. One suggestion is to apply a product and keep it wet for several days. The longer it is wet, the deeper it will penetrate. Also, make sure that the urine smell is not coming from surrounding items. Is there wood close that might be contaminated or fabric or even dirt? Urine will wick up several inches into other materials when present.

It is common not to be able to completely remove all the odor in a situation like yours (e.g., concrete or even wood). So an option used by professionals is to seal the concrete. After you have removed the majority of the odor, you can then seal the concrete with a good pigmented shellac, varnish or acrylic sealer. These sealers have microscopic holes left in them when they dry. These holes are larger than the odor molecules so odor can still get through the sealer. If you apply two coats of sealer this will help eliminate that issue. The end result is a completely satisfactory odor neutralized environment.

Get back to me with any additional questions.


  1. Ned Yuzefowich

    I have tenants that have allowed their dog to urinate and deficate on a tar and gravel roof to the point that it was covered in dog feces. Other tenants stated this has been happening for 3-4 months every day.
    Can the urine and feces break down the tar roof. If so by what process? One roofer said the roof is contaminated. Another stated that the ammonia and acidity has damaged the roof? Will the urine odor stay in the tar and smell during hot humid days. Both stated that the roof has to be replaced is this true?

    • Dog Urine

      Let me start by saying I am not an expert on roofs. I am aware though that the tar (and tar materials) are used to seal the roof and protect the building from moisture. The gravel is used to protect the tar from the sun deteriorating it and breaking it down. I don’t believe that if the roof is in otherwise good condition that the urine and feces would damage the ability of the tar to seal out moisture. And it certainly would not harm the gravel so that it could not do its function. Yes the roof would be contaminated. Anything the urine and feces comes in contact with would be contaminated. It can be decontaminated by the use of chemicals without replacing the roof. Several type of chemicals will decontaminate urine. Bio/enzymes are the primary organism used to break down sewage in treatment plants. These chemicals have to come in contact with the urine residue to break it down. You would want to clean the roof as completely as possible fist and then treat with a good chemical that will break down the urine residue and not harm the tar. As these chemicals break down the residue they eliminate the odor. When urine leaves the body it is slightly acid (uric acid) and it immediately begins to change. The Uric acid begins to be broken down into ammonia and carbon dioxide. The ammonia is highly alkaline (ph 11+). As the acidic urine reacts with the ammonia that is being created it forms alkaline salt crystals. When dried urine is re moistened it gives off ammonia gas. The odor of ammonia gas is one part of the distinctive odor that helps us to identify and locate urine. The other component of urine‚Äôs odor is off-gassing from bacteria that grow abundantly in warm, dark places. I do not know exactly how this process would affect the tar materials on the roof. Thank you for the question.

  2. kristen wilson

    Hi there!
    My husband and I recently bought a house with the contingency the old owners will pay and fix the smell of dog urine from the basement. Apparentley the dog was peeing in a couple of spots for a long time.
    Problem is they did have a professional power washing place come out and do the basment a couple days ago. Well I wentr over there to check it yestereday to see if it was gone and I smelled that pluse the wash smell together. Before I even reached the basement! It was being aired out and I’m not sure if it will be completley gone. It sure does’nt smell like it!
    They do stll have to fix it, is there any chemical or sealer I should reccomend to the current owners!?

    • Dog Urine

      Two keys to getting effective results when killing the odor associated with dog urine. One is using a chemical that works and the other is getting the chemical in contact with the urine residue. There are several types of chemicals that are effective in killing this odor. There are good and bad products in each type. Oxidation is one type that works quite well. Clorox bleach is an oxidizing product. It will work well but it has to come in contact with the urine residue for a long enough period of time to do the job. If the dogs have been urinating in the spots you mentioned for months or years then the urine has built up and soaked deep into the concrete. You of course want to make sure each area affected gets cleaned and treated heavily enough to reach the residue and counteract it. I am assuming it is concrete and an unfinished basement. If it is finished with carpet and pad and Sheetrock walls etc. then you have a larger challenge. The principles of odor removal remain the same for the different situations but different materials need to be dealt with individually. The chemical needs to contact the urine. If you are using a enzyme product, it has to come in contact with the residue and stay moist for a long enough period for the enzymes to digest the urine molecules. For concrete I would try Clorox bleach and keep it wet long enough so it can soak deep into the concrete. If necessary use two coats of a pigmented shellac concrete sealer after as much odor as possible has been eliminated.

  3. Delia Burton

    If I had a dime for every time I came to! Superb post!

  4. Great information for these tough situations! Another benefit of shellac is that is safe and non toxic once dry. The solvent used in shellac is ethyl or denatured alcohol that quickly evaporates to form a seal on just about anything.

  5. I can actually put my nose up to the upholstery where he has soiled it and can detect no cat urine smell. I bought the Starter Kit and was amazed that it really does remove the smell of urine.

    • Dog Urine

      Thanks! SUN is excellent on neutralizing all organic odors. Especially urine. All types of urine, including cat urine and of course what we specialize in, dog urine. I am glad it worked out for you. If you get SUN to the urine residue (that is in contact with it) it will remove the smell.

  6. Panama foundation

    ………………………………..Male Dog UrineGwen Crocker – Imperial MO Wednesday July 06 2011 ……………Very happy! …………………………..SUN – male cat urine-GONE!!!!!Esther Mott – Phoenix AZ Monday July 04 2011 ……………This product is unlike any other ever! Im a landlord and constantly have a problem with tenants and their cats which is the WORST kind of urine I tell everyone I know about this stuff!……………………….

  7. Get Smell Out of Concrete

    In my experience, I have found that direct sunlight, white vinegar and enzyme cleaner to be effective at cutting through the ammonia in urine and rendering it odorless. When all else fails, I will close the concrete with concrete sealer.

    • Dog Urine

      Sun light does neutralize some odors just as it does have an effect on dyes. Many times you will see the colors in carpet faded or removed next to a south facing sliding glass door when there is direct sun light on the carpet. Vinegar is acidic and will neutralize some alkalinity in urine. You use white vinegar because it has no coloring added to it that might stain the carpet . Fresh urine is acidic and with time changes to alkaline so putting vinegar on fresh urine is adding acidity to acidity. Which is not recommended. The enzymes in a good enzyme cleaner will digest and break down the molecules in urine rendering it odorless and enzymes also remove some of the staining from urine. It takes time for the enzymes to digest the urine residue so the area needs to be kept damp for a period of time (hours to days). If the enzymes dry out they are no longer active. A sealer will help but the microscopic openings (holes) in sealers are larger than odor molecules. This means even after sealing some odor can still find its way through the sealer. A second coat of sealer helps but make sure you remove as much odor as possible with cleaning and effective odor treatments before sealing.

  8. Is it possible to use your product if I still have a 7 month old puppy urinating on the slate deck she uses

    The odor is awful and even though I walk her several times a day she still urinates and poops out back.

    the deck is new and we hate using it cause of the odor. I vlean it daily with all sorts of dog products and bleaches.. help

    • You can use our products and I would suggest our Severe Urine Neutralizer SUN product for your application. It will eliminate the smell of any urine it comes in contact with. This means if the urine has soaked down into the Slate or grout, or has run along and gotten around edges or under the slate into the wood, the SUN solution needs to get those those areas and spots also. Again it will eliminate the odor of urine residue it comes in contact with but do nothing for urine it does not contact.
      As long as the puppy continues to urinate in that area you will need to continue to treat the new urine with SUN solution for it to work on the new urine.
      You can also try Clorox bleach on it as long as the area is not damaged by the bleach. The SUN and Clorox work differently but Clorox is pretty effective on urine also. It also needs to come in contact with the urine to work on it. Many times the challenge is to find and get the treatment (whatever you are using) to the urine residue. Three steps to eliminating the odor 1. Find the urine(all of it). 2. Treat all the urine with a product that is effective at eliminating the odor. 3. Use the product as directed. For example Enzyme products take hours to work so you have to keep them damp long enough for the enzymes to break down the urine thus eliminating the odor. If you do these steps you will get rid of the odor.
      Hope this helps.

  9. What about old cat urine in basement?

    • Concrete is porous so the urine can soak down into it. If you use out Severe Urine Neutralizer SUN just mix it up and apply it to the urine contaminated spots. Apply it heavy enough so it can soak into the concrete and cover it with plastic so it will soak in and not evaporate. As long as the SUN solution comes in contact with the urine residue it will eliminate the odor. It does not matter if it is old or new urine.

  10. Here is the situation. I bought an apartment Condo. Shortly after purchase I was informed by the previous tenant that the tenant before him allowed his dog to urinate on the floor. Apparently the smell comes up with humidity. He said “no big deal, seal it with kilz.” I ripped out all the flooring right down to the bare concrete. The concrete is 2″ thick. I was about to put 1.5mm underpad glued to concrete, with luxury vinyl plank over top. Professionally installed. They will be grinding the floor to level. They informed that I likely CANNOT seal the concrete as the glue for the underpad won’t stick to it.
    What do I do? The flooring is 7 grand. If I don’t fix it I have a really nice apartment that smells like piss in the summer. I’ve heard about enzyme cleaners. They want you to soak it into the concrete. My fear is it will penetration and drip into the unit below me.
    Perhaps the smell was only in the carpet? It is cold now and I don’t smell anything. The carpet was absolutely disgusting. There was also extensive tobacco smoke. That I have almost fixed. The dog urine is a head scratcher.

    • Thanks for the question. They should be able to use a glue for the pad that will stick to the Kills. I use to do it all the time. I put pad glue over all types of painted floors and it stuck just fine. It does depend on what they are using but I just used the basic glue for gluing pad to floor and it stuck painted or not and with Kills.
      Any odor neutralizer solution (including Enzymes) need to come in contact with the urine residue to work on it unless you use one that just masks the smell but those don’t remove/cover the smell for long.
      Concrete will absorb moisture but if you over wet it it could find its way through to the unit below. Most likely it would be around edges and through seems/cracks in your floor rather than right through the concrete. Concrete absorbs but the moisture will usually evaporate before it actually absorbs completely through the concrete and drips down. You have removed most of the urine residue/ odor with the carpet and pad but it could be in the concrete also. The standard procedure at this point (carpet and pad gone)is to treat the concrete the best you can without wetting it to the point of soaking through. That is you spray and pour the odor removing solution on as heavy as you dare making sure it is not heavy enough to run through and then after that dries seal the concrete with a good shellac sealer or Kills. If you don’t dare seal it for the reasons you said then you would have to skip that step. Each step helps reduce and eliminate the odor but there are times when it still comes through after you have done all you can. Usually the process will eliminate the smell but there is never an absolute guarantee. Sorry I could not be more encouraging. Probably the easiest is to ask them to use a glue that will stick.

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