Of any building material, concrete may be the easiest to overestimate. The first time I had a concrete basement floor, it seemed like upkeep would be the least of my concerns. Sure, it might need padding and carpet to make it comfortable. But when it came to stains and odors, I assumed it could easily shrug off the worst messes and tolerate my most aggressive cleaning solutions.
Fast-forward to the dog’s first accident, and reality hit me like a ton of bricks. Not only did the concrete flooring soak up the pee like a sponge, but I needed to choose my cleaners carefully if I expected to remove those pet urine odors without causing permanent damage.
I’ll share what I learned from my experiences so you know how to remove odor from concrete floor surfaces in the safest, fastest, and easiest way possible!
Quick Tips Before You Start
Protecting your concrete floor and improving your cleaning results demands a few considerations before you start, regardless of your odor-removal method. My top three tips are:
- Sweep and vacuum thoroughly before cleaning
- Clean pet urine stains immediately (do not let them accumulate)
- Rinse cleaning solutions to prevent long-term wear
Sweeping and vacuuming is crucial before cleaning any surface. If you saturate dirt on the floor with a liquid cleaner, you’ll only spread it around and worsen the stain.
When pet urine is the problem, you must thoroughly clean every accident. Doing so will prevent future accidents in the same spot. More importantly, it will stop stains from accumulating. Uric acid is severely harmful to concrete floors. As built-up acids lower the concrete’s pH, they can erode the material and even cause rebar deterioration, weakening the entire structure.
Concrete tolerates occasional weak acids, like your average distilled white vinegar. But allowing them to sit can etch and wear through sealants and concrete surfaces. Rinsing is critical to neutralize a cleaning solution’s effect on the concrete’s alkalinity. If you’re unsure of your cleaner’s pH or ingredients, play it safe and rinse the area with fresh water before letting it dry.
How To Remove Pet Urine Odor From the Concrete Floor
You can choose between numerous commercial products and DIY cleaning solutions to manage fresh urine stains. But when dog or cat urine has had time to sit, you’ll typically only get satisfactory results with an enzymatic cleaning solution or hydrogen peroxide.
Locating Urine Stains
If you smell the urine but don’t see it, get a UV flashlight. A UV light like the Vansky UV Flashlight will highlight old urine patches, reacting with the phosphorus in the stains to make them glow yellow. Using it will guarantee you hit every urine mark to make the smell disappear forever.
Pre-Treating Urine Stains in Concrete Floors
Before using an enzymatic cleaner on a urine stain, you can pre-treat the floor to remove any leftover dirt, bacteria, urine residue, and other contaminants that could affect the cleaner’s performance.
For minor urine spots, you can skip this step. As long as you thoroughly sweep the area, you should still see quality results, saving tons of time in the process.
If there is extensive urine damage across the entire floor, or you want to apply a concrete sealant, you should pre-treat with trisodium phosphate (TSP). The powdered, heavy-duty cleaner is highly toxic, requiring you to use protective clothing, gloves, and eyewear.
Follow these steps to pre-treat urine stains on the concrete floor:
- Combine ½ cup of TSP in a gallon of hot water, mixing well until dissolved
- Pour the TSP onto the urine patch, ensuring it reaches slightly beyond the edges of the visible surface stain
- Scrub well with a stiff scrub brush
- Let the product soak in for 10–15 minutes (add more TSP to the floor if the solution dries too quickly)
- Pour hot water over the spot to rinse the floor
- Vacuum the area with a wet vac to remove as much moisture as possible
- Leave the floor to dry for 24 hours or at least overnight
Note: Before applying enzymatic cleaners, ensure the area is dry of any lingering trisodium phosphate. TSP is highly alkaline and can destroy the enzymes in the cleaner and reduce its effectiveness. Let the floor dry for 24 hours whenever possible to give your enzymatic cleaner the best chance for success.
My Recommendation: Enzymatic Cleaners
An old pet urine smell will give you cleaning fits whether it shows up on your tile, carpet, or hardwood floor. And with concrete’s porosity, pet urine has the perfect opportunity to leave a long-lasting stain and challenging odors. When it’s stuck deep in your concrete floor, the best solution to remove urine entirely is an enzymatic cleaner, such as:
- BioKleen Bac-Out Pet Stain Remover
- Rocco & Roxie Stain & Odor Eliminator
- Zeiff Pro-Grade Multi-Purpose Probiotic Enzyme Cleaner
Soap and other conventional cleaning products wash over embedded uric acid crystals without removing them. The bacteria and enzymes in enzymatic cleaners break down targeted urine compounds to make them whisk away.
An active product, the enzymatic cleaner will continue breaking down any urine it reaches, ensuring you eliminate every last trace. Complete removal is the only way to keep urine odors from returning. As most enzyme cleaners are pH-neutral, you can let them sit to do their job without worrying about harming your concrete.
How To Use an Enzymatic Cleaner for Concrete Floor Odors
Spray an enzymatic cleaner liberally over the urine stain, adding more if you notice it drying too quickly. To slow evaporation, cover the spot in plastic wrap. The cleaner will sink into the concrete, degrading any uric acid crystals and urine residue it passes. Repeat the process until the urine odor is gone.
Hydrogen peroxide is one of the best household stain removers, an effective oxidizer that clears away discoloration and the pet urine odor. If you have a deep pee or poop stain that an enzyme cleaner won’t remove, hydrogen peroxide can lighten it and restore the look of the concrete surface. Here’s how you can use it on a tough pet urine stain:
- Mix a cup of hydrogen peroxide with a drop of dish soap and one teaspoon of baking soda
- Pour the blended solution over the affected area, and scrub it in with a firm scrubbing brush
- Let the solution sit for at least 15–30 minutes
- Rinse the spot well with hot water
- Repeat as necessary until the stain is gone
Note: You can also treat the spot with hydrogen peroxide alone. Although you lose the added cleaning power of soap and baking soda, you don’t have to worry about rinsing soap residue afterward. The hydrogen peroxide can sit until it converts to water and will harmlessly dry and evaporate away.
Vinegar and Baking Soda
Vinegar and baking soda can make an easy, gentle, and effective stain and odor-removal combo when you’re dealing with fresh pet urine. The mild disinfecting power of vinegar will help remove microbes, while both components can reduce the urine smell. Follow these steps to use them together on a concrete floor:
- Mix distilled white vinegar with water in a 1:1 ratio in a spray bottle
- Spray the stain liberally with the solution and scrub it in
- Rinse the spot with fresh water
- Sprinkle a layer of baking soda over the area, and leave for at least an hour to finish deodorizing the spot
- Vacuum the baking soda when the time is up
Tip! If you don’t want to use trisodium phosphate (TSP), vinegar can make an effective initial surface prep before you use an enzymatic solution. Spray your vinegar and water solution, scrub it in, and rinse with fresh water. Once dry, you can apply the enzyme cleaner to finish the job.
Soap and Water
Another suitable surface prep for an enzymatic cleaner, soap and water can also handle minor recent dog or cat urine messes. Mild dish liquid, like blue Dawn, is pH-neutral and unlikely to cause issues with the concrete surface. Add a few drops of dish soap to hot water to make a sudsy mixture, and apply it to the stain. Scrub in the soapy water and rinse, and your floor should be stain-free!
Although I typically don’t recommend steam as a first choice in tackling urine in carpet, it can be practical for a concrete floor. A few passes with a steam mop, like the Bissell PowerFresh 2-in-1 steam mop, makes an excellent surface prep before you use an enzymatic cleaner. Porous concrete allows steam to penetrate deep to lift water-soluble contaminants, degrease, and sanitize the floor.
Most steam mops only require water to clean sealed and unsealed concrete surfaces. But when you’re dealing with a foul odor, a scented additive can go a long way in flipping the concrete’s smell from terrible to terrific, especially if you don’t have an enzyme cleaner handy. Products like Bissell Eucalyptus Mint Demineralized Steam Mop Water will instantly refresh the space after cleaning by adding a fresh aroma.
How To Remove a Musty Smell From Concrete Floors
Hydrogen peroxide and, to a lesser extent, vinegar make effective mold and mildew removers for concrete. You can also lean on classic bleach to safely eliminate a musty smell.
Cleaning Musty Odors With Bleach
Mix chlorine bleach with water in a 1:16 ratio. Dip a scrub brush in the solution, and scrub the affected area. Let the solution sit for 15–30 minutes. Rinse with fresh water, and remove excess moisture with a shop vac. Repeat the process if you still notice a musty smell from the concrete floor.
Warning! Chlorine cleaners can be hazardous to your health with improper use. Wear protective gear and ensure proper ventilation before using bleach, and always dilute it to a safe level.
For simpler odor removal, use a commercial cleaning product like RMR-86 Instant Mold and Mildew Stain Remover Spray. Although it also uses sodium hypochlorite as the active ingredient, RMR-86 is fast-acting and easy to use. Spray it on the musty-smelling spot, and the cleaner will refresh your concrete floor without scrubbing or rinsing.
How To Clean Gasoline Smells From a Concrete Floor
Oil and gasoline spills are frequent occurrences on a concrete garage floor. In most instances, leaving them to soak in can leave some powerful off-putting odors. Fortunately, gasoline evaporates eventually. Leave the doors and windows open, and the smell will fade in several days, depending on the stain’s severity.
If you simply can’t wait to deodorize your oil-stained concrete floors, several hassle-free solutions will relieve the smell. Tackle fresh, wet stains with a thick layer of absorbent material, such as kitty litter, baking soda, or cornstarch. For older, dried oil stains, use soap and water or a commercial degreasing solution.
How To Clean Oil Odors With Soap
Mix a few drops of dish soap in a bowl of warm water. Dip a scrub brush in the solution, and scrub the stain. Rinse with fresh water, and repeat until the odor is gone.
Degreasing solutions are the ideal options for efficiently removing oil-based staining across an entire floor and make an excellent pre-treatment to ready concrete for sealing. Cleaning products to consider include:
Follow the manufacturer’s instructions carefully when using any degreasing solution. Some contain harsh chemicals that require rinsing, while others can dry into the concrete. With concrete’s porous nature, removing the gasoline odor entirely may take several applications.
How To Remove Odors From a Concrete Floor
While cleaners like hydrogen peroxide and enzyme cleaners remove odors at the source, you can use a simple solution to make the room smell pleasant until you can clean it.
Open doors and windows will push out stale, smelly air, and room sprays can quickly mask the stench of mold, urine, and oil-based stains. Meanwhile, an odor eliminator like bowls of baking soda or activated charcoal packs will draw in odorous compounds to improve the air quality.
Warnings and Insights for Cleaning Concrete Flooring
Solid concrete surfaces may handle claws, heels, and heavy impacts better than most flooring, but there’s plenty that can wear it away chemically. The biggest concerns? Acids, sulfates, and salts, many of which appear in everyday cleaning solutions.
Acids are one of the more common threats to concrete. Low-pH cleaners can attack assorted cement compounds, dissolve aggregate, and disrupt the alkaline environment the concrete structure needs to stay stable. Meanwhile, substances like sulfates and salts interact with concrete components to add stress and increase the likelihood of scaling and cracking.
Concrete floors can vary in composition, affecting their resistance to chemicals. Some of the factors that can impact concrete’s resilience include:
- The concrete’s permeability
- Protective coatings
- The aggregate type
- The amount of cement
Identifying these variables and determining the concrete’s tolerances isn’t easy for the average homeowner. I recommend playing it safe and assuming your concrete floor is highly vulnerable.
In general, a neutral-pH or alkaline cleaner is preferable. Mild acids like vinegar can work into the mix, providing a safe cleaning solution with the proper approach and thorough rinsing.
How To Prevent Odors in Concrete Flooring
Apart from frequent cleaning, the most practical way to prevent odors from sinking into your concrete floor is with a sealant. After pre-treating and cleaning your floors, you can apply a film-forming coating like epoxy to keep liquids from penetrating the concrete surface.
For ease of use and to maintain the look of your concrete, a penetrating sealer, such as Siloxa-Tek 8500, will give long-lasting protection against urine, mold, oil, and numerous other stains.