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 salts allow crystals to reform as soon as moisture (humidity for example) is introduced. This releases a gas that has a 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.
Clean the pet urine stains with TSP
After you have identified where the urine is located, 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.
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 stains, 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 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.
Steps for removing pet urine odors from concrete
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How do you get the smell out of a concrete floor?
What kills the smell of dog urine?
Make a solution of baking soda, peroxide and any dish detergent. The combination of the three is often powerful enough to drive away even the strongest of urine smells. Mix together 8 fluid ounces of peroxide, 3 tablespoons baking soda and a few drops of dish detergent.
How long does pee smell last on concrete?
After 4–8 hours, you can clean the area again with warm water, and then let it dry. The smell should be completely gone, but in the unlikely case that some remnants are still present, you may need to repeat the process.